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Armagh Observatory
Annual Report
Calendar Year 1998
Prepared by the Director
M.E. Bailey
This report briefly summarizes research and other activities of the
Armagh Observatory during the calendar year 1998.
Contents
1 Introduction 1
2 Principal Areas of Research 1
3 Staff Movements 2
4 Staff 2
5 Visitors and Seminars 3
6 Research 3
6.1 M. de Groot, Senior Research Associate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
6.2 W.M. Napier, Senior Research Fellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
6.3 C.J. Butler, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.4 J.E. Chambers, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.5 J.G. Doyle, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.6 C.S. Jeffery, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.7 M.D. Smith, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.8 M.E. Bailey, Director . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7 Public Understanding of Science 11
7.1 Press, Radio, Television and Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.2 Astropark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.3 Heritage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8 Items of Concern 12
A Armagh Observatory Staff, 1998 13
B Refereed Journal Publications, 1998 15
C Armagh Observatory Seminars, 1998 18
D Talks by Armagh Observatory Staff, 1998 19
E Identified Media Mentions, 1998 21
F Public Queries, 1998 24
G Astropark Display Panels 27

1 Introduction
The Armagh Observatory, founded in 1790 by Archbishop Richard Robinson, is a modern astronomical
research institute with a rich heritage. It is situated close to the centre of the City of Armagh in grounds
which include the Armagh Planetarium and a scale model of the universe known as the Armagh Astropark.
The Observatory, which is one of the UK and Ireland's leading scientific research establishments, receives
baseline support from the Department of Education Northern Ireland (DENI) to maintain the grounds,
the Grade A listed building and some 15 core­funded research and support staff.
In addition to these established posts, there is a fluctuating population of short­term research staff,
currently numbering 18. These include research students, postdoctoral research assistants, senior research
associates, and visitors, many of whom are engaged on fixed­term research contracts for periods ranging
from one to three years or more. Overall, around 25 astronomers of graduate or postdoctoral status are
actively studying Stellar Astrophysics, the Sun, Solar System astronomy, and the Earth's climate.
Facilities at Armagh Observatory for computing and data reduction are mostly excellent and include
a local Starlink node funded by the Particle Physics and Astronomy Research Council (PPARC). Ob­
servatory staff receive regular awards of telescope time and research grants from the PPARC and other
organizations.
Research interests of Observatory staff currently include (i) Stellar Astrophysics (including star for­
mation, astrophysical jets, the Sun, cool stars, hot stars, helium stars, star­spots, flares, circumstellar
dust), (ii) Solar System Astronomy (including celestial mechanics, planet formation, dynamical evolu­
tion of comets and asteroids, interplanetary dust), and (iii) Solar System -- Terrestrial Relationships
(including solar variability, climate, accretion of interplanetary dust and cometary impacts). In addition,
Observatory staff maintain an active programme of Public Understanding of Science (PUS), via lectures,
popular astronomy articles and interviews with the press, radio and television. Further details concern­
ing the research interests of all the Observatory staff may be obtained from the Observatory web­site at:
http://www.arm.ac.uk/.
The Mission Statement of the Armagh Observatory and Planetarium is:
To advance the knowledge and understanding of astronomy and related sciences through the
execution, promotion and dissemination of astronomical research nationally and internation­
ally in order to enrich the intellectual, economic, social and cultural life of the community.
The Armagh Observatory participates in the UK Research Assessment Exercise, held in 1992, 1996
and again in 2001. Staff at the Observatory achieved a Grade 4 in the Physics Unit of Assessment (on a
seven­point scale 1­5 \Lambda , with 5 \Lambda the highest) in each of the 1992 and 1996 RAEs. This grade corresponds
to `Research quality that equates to attainable levels of national excellence in virtually all sub­areas of
activity, possibly showing some evidence of international excellence, or to international level in some and
at least national level in a majority.'
2 Principal Areas of Research
Staff at the Armagh Observatory carry out research in the following principal areas:
1. Stellar Astrophysics, including star formation, astrophysical jets, the Sun, so­called `cool' stars,
evolved hot stars and helium stars, star­spots, flares, the physics of stellar chromospheres (the
transition layer between the stellar surface and the extremely hot outer layers of stellar atmospheres
known as the corona), the mechanisms of coronal heating in active stars including the Sun, the
environments around evolved stars, and stellar clusters.
2. Solar System Astronomy, including celestial mechanics, numerical and semi­analytic methods, the
origin and dynamical evolution of comets, asteroids and meteorites, the evolution of interplanetary
dust; the formation of Edgeworth­Kuiper belt objects, the origin and evolution of planetary systems,
and the structure and evolution of extra­solar planetary systems.
3. Solar System -- Terrestrial Relationships, including solar variability and climate (mediated by Sun­
spot and solar flare activity, and galactic cosmic rays), the effects of accretion of cosmic dust and
larger bodies (comets and asteroids) on the Earth, the impact hazard posed by comets and asteroids,
and the possible link between interplanetary bodies and the historical and climatological records.
Staff at the Observatory have also carried out research on (i) meteor streams, (ii) testing the apparent
quantization discovered in extragalactic redshifts; and (iii) climate change at Armagh during the past
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two hundred years. The Armagh climate series, which is one of the longest in the world from a single
site, is of particular interest in being (a) virtually continuous since its inception in 1795, and (b) only
slightly affected by surrounding urban development.
A few highlights from 1998:
ffl Brendan Byrne Memorial Meeting: a highly successful conference with more than 60 participants
from 15 countries, 1998 September 2--4. The proceedings of the conference Solar and Stellar Activity:
Similarities and Differences, edited by C.J. Butler & J.G. Doyle, were published as volume 158 in
the ASP Conference Series.
ffl 1998 Robinson Lecture: delivered by Professor John C. Brown of the University of Glasgow, As­
tronomer Royal for Scotland. Professor Brown's lecture `Life in a Stormy Universe' was well received
and published in summary form in the Irish Astronomical Journal 26, 21--22, 1999. The lecture
was followed the next day by a Schools Lecture `Black Holes and White Rabbits'. The events were
well attended and enjoyed by all.
ffl Media Coverage: The Observatory is the principal point of contact for astronomy in both Northern
Ireland and the Republic of Ireland, with frequent mentions in the national and international press,
and on radio and television. The 147 identified occasions on which the Observatory was noted in
one or another medium during the calendar year 1998, up almost 40% from the number in the
previous year, are listed in Appendix E. The success of this activity, which promotes astronomy
and disseminates the research output of the Observatory to a non­professional audience, highlights
the strength of public interest in astronomy and related sciences, and in particular in work currently
carried out at Armagh.
ffl External Grant Income: Total external grant income was $195k during the financial year 1998/1999,
a significant fraction (47%) of the DENI recurrent grant­in­aid. Total external income during the
year was $213k.
3 Staff Movements
The Grounds and Meteorological Officer, Mr John McGinn, left the Observatory at the end of 1998 June
for a new position in the south of England prior to seeking work abroad. Pending an external review of
the grading of the position, completed towards the end of 1998, the post was left vacant with essential
grounds maintenance work being carried out by contractors. During this time, meteorological readings
were taken primarily by the Librarian with assistance from other staff.
Two new PPARC PDRA grants came into effect during the year, namely those relating to David J.
Asher and Darko Jevremovi'c. These in effect replaced two other postdoctoral grants (relating to Victor
Clube's Leverhulme Fellowship and Alex J. L¨obel's PPARC PDRA position), which finished during the
same period.
Dr Michael D. Smith joined the Observatory as Research Astronomer on 1998 October 1. Dr Smith
has research interests in star formation, stellar and galactic jets and magnetohydrodynamics.
Five new postgraduate students were welcomed to the Observatory: Ms Sandra Jeffers (studying for
an M.Phil.), Mr Ferhat Ozeren (visiting from Ankara, Turkey), Ms Pilar Monta~n'es Rodr'iquez, Mr Enric
Pall'e Bag'o, and Mr Il'ia Roussev (all studying for a Ph.D.). Mark Bailey and John Chambers began
co­supervision of another Ph.D. student, namely Mr Nick Sleep, who is a part­time student working
primarily with Dr Barrie W. Jones of the Open University.
Four students were awarded the degree of Ph.D. in 1998, namely Mr Duncan C. Foster, Ms Mar'ia
Teresa Eibe, Mr Pedro J. Amado and Mr Luis Sarro. A fifth student, namely Mr Alan D.S. Coughlin,
gained an M.Phil.
4 Staff
The staff position at the Armagh Observatory on 31 December 1998 is shown in Appendix A. Individuals
are identified by their 3­letter (sometimes 2 or 4) Starlink computer username (full e­mail address:
xxx@star.arm.ac.uk), together with their job­title and an indication of their principal function in the
Observatory. Funding to support these staff comes primarily from the DENI grant­in­aid ($443k) and
external income ($213k), the latter mostly in the form of research grants obtained through competitive
application and peer review from the PPARC.
2

The Observatory runs an extremely lean administration, currently comprising three staff (mc, ambn,
lfy), one of whom (lfy) is shared equally with the Planetarium. The gross cost of salaries for this
administrative support is less than 7% of total income. In addition, the Observatory is fortunate in being
able to draw on some very capable support staff (two computer staff, one Librarian/PRO/Archivist,
and one Grounds/Meteorological Officer), whose salaries together account for a further ¸11% of total
income. It is a credit to all these staff that the entire administrative, academic and grounds support for
the Observatory is achieved at a total cost for salaries of less than 20% of the total income.
5 Visitors and Seminars
The Observatory maintains an active research visitors programme, encompassing students, post­doctoral
research assistants and more senior researchers, and hosts a research seminar approximately once per
week during the academic year. The calendar year 1998 saw working visits from 9 astronomers of post­
doctoral status or higher, with additional visits by three Ph.D. students based elsewhere. During 1998
Observatory staff also supervised 6 school work experience students, 4 A­level summer students under
the Nuffield scheme, 4 QUB undergraduates on project work, 1 Trinity College Dublin (TCD) final­year
undergraduate project, and 5 other undergraduates on miscellaneous summer work. The programme of
research colloquia for 1998 (numbering 33 separate talks) is listed in Appendix C. It is notable that more
than 20 of these seminars were provided by external speakers.
A further aspect of the visitors programme is the high frequency of visits by members of the public
and by small groups. Observatory tours are usually conducted by the Librarian, who in 1998 showed
approximately 1000 individuals from more than 16 countries around the Observatory. This number is up
by 100% compared to the previous year, a remarkable result which suggests heightened public interest
in astronomy in Armagh City and District, and indicates the success of the Armagh Observatory's `open
door' policy to attract members of the public, groups and societies.
It is recognised, however, that visitor numbers should be kept under review, and that they should
not increase to the extent of impeding or interfering with the primary research activity and objectives of
the institution. A new policy of attracting electronic visitors (`e­visitors'), via the Observatory's web­site
(http://www.arm.ac.uk/), was introduced during the year, and it is anticipated that steady improvements
in the number of visits to the Observatory's web pages will take place in future years. The number of
e­visits is already measured in tens of thousands per year.
Visitors during 1998 included nearly 20 group tours, ranging from specialist groups and societies (e.g.
the Armagh and District Radio Club, the Clerical Reading Society, Astronomy Ireland, and the Irish
Astronomical Association), to school children (e.g. the Heartstone Project, the John Scottus School,
Dublin) and local groups (e.g. the Armagh and Dungannon Soroptimists, the Armagh Natural History
and Philosophical Society etc.). In addition, the Observatory received a number of VIPs, including
Mr Lembit ¨
Opik MP, a party of senior civil servants from Bangladesh, Professor George Bain (QUB
Vice­Chancellor) and Professor John Brown (Astronomer Royal for Scotland).
6 Research
The scientific reputation of the Armagh Observatory depends largely on peer assessment of sometimes
highly technical scientific publications, and on the one­to­one interactions between Armagh Observatory
staff and other research scientists, whether at conferences, or in collaborative research projects between
the Observatory and groups in other countries. A subset of the total research and other public output,
namely the list of refereed journal publications during 1998, is given in Appendix B. A second subset,
namely the list of more than 50 public talks delivered by Observatory staff during 1998, is given in
Appendix D.
These examples illustrate the variety of routes by which the research results of Observatory staff are
communicated, namely through talks or popular articles in the local, national or scientific media; at
conferences, seminars and workshops; in books; in refereed scientific publications, journals or conference
proceedings; and in a variety of non­refereed articles, some of which nowadays are in entirely electronic
form (e.g. contributions to CD­ROMs such as `Deep Impact: An Interactive and Educational Guide
to Comets and the Universe', United International Pictures & Dreamworks Pictures, April 1998). All
these forms of public output, which are substantial, help to raise the national and international profile of
astronomy, and in particular of astronomy at Armagh.
A further indicator of the Observatory's research activity is the amount of external research income,
raised mostly through a competitive process of grant application and peer review. In 1998, the total
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external grant income was ¸$195k, representing a substantial fraction (47%) of the total DENI recurrent
grant in aid. Research activity and external income generation are areas where economies of scale work
extremely well: larger research groups attract the lions share of available research council funding and,
in view of the Observatory's current size, there remains room for improvement, given investment in
additional research staff.
The remainder of this section summarises some of the research results obtained in 1998 by the Ob­
servatory's senior research staff and associates.
6.1 M. de Groot, Senior Research Associate
Dr Mart de Groot continued his research into the behaviour of Luminous Blue Variables (LBVs):
1. In collaboration with Drs Van Genderen (Leiden, Holland) and Sterken (Brussels, Belgium) papers
XV and XVI in the series `Light Variations of Massive Stars' were published. These dealt with
the brightness variations of several massive stars in the two nearest neighbour galaxies, namely six
stars (R85, R99, R103, R110, R123 and R128) in the Large Magellanic Cloud (LMC) and two (R42
and R45) in the Small Magellanic Cloud (SMC). Several of these stars were identified as genuine
LBVs, pulsation periods were determined for all of them, and theoretical models were discussed.
2. As a part of the same collaboration, paper II in the series `Cyclicities in the light variations of
LBVs' was published. It dealt with R40 in the SMC which was found to be subject to normal S Dor
(slow pulsation­like) phases.
3. Also in the same collaboration, another paper on the brightness variations of one of the brightest
stars in our Galaxy, j Carinae, was completed. This confirmed earlier findings, and also allowed
refinement of the previous model in terms of the complicated interaction of the colliding winds from
the two stars present in this binary and the hot luminous disk around one of them.
4. Research on the peculiar LBV P Cygni continued with regular observations done by the Automatic
Photoelectric Telescope Service in Arizona. An investigation in collaboration with Dr Markova
of the Bulgarian National Observatory and Dr Scuderi of the Catania Astrophysical Observatory
(Italy) into the behaviour of P Cygni's spectral lines, especially in relation to the star's brightness
variations, was started and almost concluded. This should be published by the end of 1999.
5. On the invitation of the Editor of Space Science Reviews, an article reviewing our present knowledge
of P Cygni was written in collaboration with Dr Israelian from the Astrophysical Institute of the
Canaries, Spain. At the time of writing this report it has been accepted for publication.
6. In preparation for a study of the brightness variations of P Cygni during the last 50 years, many
observations were collected from a variety of sources and subjected to detailed analysis to arrive at
a set of data that is as homogeneous as possible; this is not an easy task when so many different
observers and instruments are involved!
7. Two summer students from QUB worked on a project to investigate a possible correlation between
the behaviour of a selected number of spectral lines and the simultaneous photometric variations
of P Cygni. Some tentative conclusions were drawn, but these need further investigation as under
item 4. Two further summer students, grant­aided under the Nuffield scheme, worked on different
data sets of LBVs to find (quasi­)periods in a number of them, supporting research related to that
under point 1 above.
8. PUS: On the invitation of the Cura¸cao Astronomy Club the total solar eclipse of 1998 February 26
was observed, and two lectures delivered on the origin and future of the Universe. Four extensive
radio interviews about the eclipse were given for three different radio stations, for a total of 4 hours
45 minutes.
6.2 W.M. Napier, Senior Research Fellow
Dr Bill Napier continued his research into the origin and evolution of interplanetary dust, the effects of
dust and small­body impacts on the Earth, and the analysis of extragalactic redshifts.
1. A variable zodiacal cloud model was developed in order to investigate the variable accretion rate
of extraterrestrial dust on the Earth. The model considers a population of comets, injected at
random into short­period, Earth crossing orbits, where they disintegrate, producing dust. The dust
4

particles so produced undergo mutual collisions as well as spiralling into the Sun under the influence
of radiation pressure. Preliminary results show that large fluctuations in the dust population are
likely to result.
2. An analysis of the recession velocities of nearby galaxies (103 with velocities less than 500km s \Gamma1 ,
out to a distance of ¸10Mpc) was carried out with a view to checking whether a redshift periodicity
of 37.5km s \Gamma1 exists in this dataset, as had been found in other extragalactic datasets. The new
analysis yielded a local cosmological expansion of 62 \Sigma 5 km s \Gamma1 Mpc \Gamma1 , closely similar to the corre­
sponding values 64 \Sigma 6 and 63 \Sigma 4 found by the two groups studying Type Ia supernovae. However,
the most significant (and extraordinary) result to emerge from this study was the confirmation that
there is indeed a periodicity of 37.5 km s \Gamma1 in the recession velocity of these nearby galaxies, a
result previously found by Napier and a co­author in a more accurate dataset extending to 2600km
s \Gamma1 .
3. Reviews of the small­body impact hazard, and the dust hazard, on timescales relevant to civilization,
were prepared and published.
4. Miscellaneous activities: student supervision at various levels (e.g. two QUB undergraduates, one
school work experience student), and acting as external examiner to a Ph.D. student at the Uni­
versity of Wales at Cardiff. The alleged meteorite crater near Belleek was investigated early in the
year with Mark Bailey and Tom Mason and shown not to be meteoritic.
5. PUS: five presentations were made, ranging from IAU Symposium 194 (Armenia) to colloquia
and popular talks. In addition, a popular review (`Comets, Dragons and Prophets of Doom')
was published in the PPARC journal Frontiers, and a novel (`Nemesis'), a thriller with a science
base exploring the issue of the asteroid impact hazard to civilization, was written and published by
Hodder Headline plc. These outreach activities resulted in wide media coverage, including interviews
for television documentaries, full­page reports in the national press as well as interviews on national
BBC radio. The book `Nemesis' has currently sold more than 15,000 hardback copies. The PPARC­
funded STEM course on scientists and the media was found to provide a useful introduction to
dealing with the various mass media.
6.3 C.J. Butler, Research Astronomer
Dr John Butler has carried out activities in the following main areas:
1. Observation and modelling of stellar flares: Two observing runs were undertaken (with D. Jevre­
movi'c) in 1998, as part of this project, one at the Observatoire de Haute Provence and the other
with the William Herschel Telescope (WHT) on La Palma. The second run provided excellent high
time­resolution optical spectrophotometry of a flare on the nearby active dwarf AD Leo, using a
new drift­scan technique on a CCD. This is believed to be the first time that optical spectroscopy
of a stellar flare has been obtained with a time­resolution better than 5 seconds.
A computer model, based on the MULTI model atmosphere code, has been used to fit the time
profiles of the emission lines of hydrogen. Whilst broad overall agreement in the shape of the profiles
is found, there are differences in their detailed behaviour and in the relative fluxes of the lines as
modelled and observed. Further computations are in progress.
D. Jevremovi'c has continued to write up his thesis on the behaviour of the Balmer lines during
stellar flares.
2. Angular momentum of late­type cluster members: This programme (with Dr Armin Thiessen) has
continued during the year with the preparation and submission of a paper containing the results
obtained by Duncan Foster on the cluster Stock 2. An observing proposal for direct imaging time
on the 40­inch Ritchey­Chr'etien Telescope at Siding Spring Observatory received an award of a
week in February 1999.
3. COROT: Several applications were made for high­dispersion spectroscopic time on 2­metre class
telescopes to assist our French colleagues in the selection of suitable targets for this very interesting
space project on stellar seismology. No allocation of telescope time was made for 1998, but one
week has been granted by the South African Astronomical Observatory (SAAO) in 1999 July.
5

4. Climatology: A new PhD student, Enric Pall'e Bag'o, has started a project on the link between solar
activity and cosmic rays on clouds and their possible influence on the Earth's mean temperature. A
preliminary examination of the sunshine data for Armagh and three other Irish sites indicates (1) a
gradual increase in the cloud factor since the late 19th century, probably as a result of the gradually
increasing sea surface temperature associated with global warming. A correlation between the cloud
factor and solar cycle length is apparent, but it is not yet clear if this represents a true physical
connection.
5. Meteorology: Collaboration with two external scientists has allowed some progress to be made
in the compilation of those daily meteorological readings not previously entered on to computer.
David Smyth of the University of Edinburgh has undertaken the verification of the daily rainfall
data previously compiled and some additional data are currently being compiled by the Department
of Agriculture Northern Ireland.
Professor Alistair Dawson of the University of Coventry is currently compiling the pressure data for
a joint study on the pressure oscillation of the North Atlantic region over the past two centuries.
6. Historical Studies: Several short biographies of previous members of staff at Armagh and Dunsink
Observatories have been written.
7. Conference: A three­day conference entitled `Solar and Stellar Activity: Similarities and Differences'
was organised and held in Armagh in 1998 September to commemorate the life's work of Dr Brendan
Byrne. It was attended by more than 60 scientists working in the field, many of whom had previously
collaborated with Dr Byrne. The proceedings of the meeting were edited by C.J. Butler and J.G.
Doyle and published by the Astronomical Society of the Pacific in their conference series.
8. Administration: An Equal Opportunities policy was agreed and ratified by the MSF Union and the
Observatory's Governing Board. Discussions on Grievance, Disciplinary Procedures and Conditions
of Employment, continue.
9. Further Research Plans: Future progress in the flare modelling project will require an additional
Ph.D. student to take over from Darko Jevremovi'c (djc). If appointed he/she will be supervised
jointly by John Butler and Gerry Doyle, with assistance from djc. We propose to use similar codes
to those employed by djc to model solar flares as well as other stellar flares for which we already
have data in hand. An XMM proposal for this project has been made.
The cluster programme is currently handicapped by the lack of success in obtaining additional
spectroscopic time on telescopes of 2--4 metre class. Applications have been made for time on the
Isaac Newton Telescope (INT) and the WHT which could allow further progress to be made. A
switch in emphasis to wide­field imaging, if successful, promises to be a faster route to the end
result than the previously attempted techniques involving high­resolution spectroscopy.
Examination of the influence of solar activity on cloudiness via the sunshine data will continue.
Also it is planned to use the new data banks on cloud factors to make a thorough reappraisal of
the effect of cosmic rays on cloud factors.
6.4 J.E. Chambers, Research Astronomer
Dr John Chambers has made detailed computer simulations of the origin and formation of the Earth and
the inner planets. These build upon earlier work by Chambers and George Wetherill, of the Carnegie
Institution of Washington, whose computer calculations had predicted that planets would tend to have
elliptical orbits rather than the almost­circular ones we see in the Solar System. If true, this would have
profound implications for the habitability of extra­solar planets, as elliptical orbits induce large swings
in climate. The new simulations have a more interesting range of outcomes. Several calculations yielded
Earth­like planets moving on almost circular orbits, which allows them to have stable climates. However,
a significant fraction of planets are likely to have highly elliptical orbits, so that they are unlikely to be
able to support life.
A new algorithm has also been developed for solving the N­body problem --- a tough computa­
tional task necessary to understand many aspects of astrophysics. In particular, the new method has
considerably speeded up computer simulations of planet formation, making it possible to get a better
understanding of how the Earth, the Moon, the planets, and the asteroids formed.
Michael Brown (a final­year student at Trinity College, Dublin) extended earlier work on the stability
of planetary systems. He finds that many systems become unstable if one waits long enough. This
6

instability is especially likely if the planets have a wide range of masses, due to the occurrence of chaotic
motion generated by repeated configurations of the planets.
Other activities include:
1. Successful application for an NRC grant (USA) for a one­year sabbatical to work at NASA/Ames
Research Center, California. In­depth investigations of the origin of the Earth and Moon, the
inner planets, and the asteroid belt will be carried out in collaboration with planet expert Dr Jack
Lissauer.
2. On­going research collaborations, for example with: J.J. Lissauer and E. Rivera at NASA/Ames
Research Center, on the formation of the inner planets and the Moon; A. Morbidelli and J.­M.
Petit at the Observatoire de Nice, on the origin and early evolution of the asteroid belt; M.A.
Murison at the US Naval Observatory, on developing better computer algorithms for solving the N ­
body problem; G.W. Wetherill at Carnegie Institution of Washington on planet formation and the
formation and evolution of the asteroid belt; N.W. Evans and S. Tabachnik at Oxford University,
on possible primordial belts of asteroids in the inner solar system.
3. Presentations: included lectures at University of Durham, the University of Oxford and Queen
Mary College, London, on the origin of the terrestrial planets and on the formation of planetary
systems. In addition, lectures were given at various national and international astronomy meetings,
including Lisbon (Portugal), Namur (Belgium) and Madison (USA).
6.5 J.G. Doyle, Research Astronomer
During 1998 Dr Gerry Doyle was involved with three PPARC PDRA research grants, and was also a
co­organiser of two international conferences (the COSPAR Symposium `Activity Observed in the Sun
and in Similar Stars', and the Armagh Cool Star Workshop `Solar and Stellar Activity: Similarities
and Differences'). He was Associate Scientist with the CDS and SUMER instruments on SOHO. Many
refereed and other papers or research notes were published during the year, while research visits were
undertaken to NASA (Goddard), and the DIAS (Dublin). He acted as external examiner to a Ph.D.
student at the University of Glasgow.
Gerry Doyle leads the solar physics group at Armagh, with a particular focus on using data from
satellites such as SOHO to infer the structure of the Sun's surface layers and its outer atmosphere or
corona. One of the main questions in this field is how the corona is heated to temperatures in excess
of one million degrees compared to the surface temperature of 6,000K. Over the years many different
theories and models have been proposed, most of these based around wave­type heating.
Nano­flares In the mid­eighties, John Butler and Gerry Doyle, while comparing the radiative energy
output from the quiet corona of some twenty stars similar in many ways to our own Sun, found that
there was close to a one­to­one correspondence with the total amount of energy radiated by flares on
these stars during a period of say one day. We suggested the term micro­flaring to describe this result,
and proposed that the outer atmospheres of these stars were heated via flare­like activity.
At around the same time, an astronomer (E. Parker) in the USA was working on a similar idea but
applied to the Sun. His suggestion was similar to ours, but the scale was slightly different. He suggested
that the outer atmosphere was heated by a large number of very small events, each having the energy of
only a billionth that of a large solar flare, hence the term nano­flare.
What has SOHO seen? SOHO is a joint ESA/NASA mission, which was launched in 1996 with
an array of different instruments, designed to study various aspects of solar activity, including heating
of the solar corona. Over the last few years, we and others have obtained many different sequences of
observations which have allowed us to search for fast time­scale enhancements in radiative intensity, line­
shifts (i.e. the line centre being shifted from its normal rest wavelength), and whether there is evidence
that these events recur with certain periods.
Previous observations have shown that there is a slight shift from the rest wavelength of lines formed
between the chromosphere, which has a temperature of 20,000K, and the corona. However, all of the
previous work suggested that this line shift should disappear at about 250,000K. With SOHO we have
shown that this is not the case, in fact the line shift changes from being red­shifted below 400,000K (i.e.
it is moving away from us, in other words down towards the surface of the Sun) while hotter gas (at
temperatures in excess of 400,000K) moves towards us, i.e. upwards, away from the Sun.
7

We have now started to develop models to explain this. Our present models suggest that some form
of magnetic reconnection takes place at a temperature of about 250,000K, thereby producing mostly
down­flowing material below this value (For example, the strong C IV line formed at 100,000K shows
precisely this behaviour.) On the other hand, the strong Ne VIII line formed at 500,000K shows the
opposite behaviour. Output from detailed spectral modelling clearly shows that both lines are initially
at their rest position, but following a nano­flare the spectral lines start to move in opposite directions at
a few km s \Gamma1 in very good agreement with observations.
We have now followed up our early observations with some long time­series studies involving a line
formed at 250,000K. This is extremely interesting because one can clearly see a series of short impulses,
each lasting only about 30 seconds, occurring every 200 seconds and sometimes more often. We believe
that this is strong evidence in favour of micro­flaring and are currently up­dating our modelling codes to
make it easier to vary the key input parameters such as energy, duration of the nano­flare, initial electron
density and temperature etc.
Although we believe that nano­flaring is a prime source for coronal heating, we do not believe that it is
the main one. In fact it is likely that several different mechanisms are working simultaneously, depending
on the local conditions of the plasma. For example, observations taken from regions close to the solar
limb (again taken in a spectral line formed at 200,000K) show a clear periodicity of perhaps 20 to 30
minutes in the intensity, which takes us back to some of the early theories on wave heating. Although
a great deal has been learned about the Sun from SOHO, there is still a lot more to be done, not only
observationally, but also from theoretical modelling.
6.6 C.S. Jeffery, Research Astronomer
During the final stages in its life, a star is transformed in ways which remain poorly understood. It is well
known that, at the end of hydrogen burning, a star expands to become more luminous and cooler --- a
red giant. Thereafter, a low­mass star may contract and expand several times over, becoming alternately
hotter/smaller (subdwarfs) and cooler/larger (giants) than the Sun. Each transformation is a response
to changes in chemical composition in the stellar interior as nuclear reactions convert one source of fuel
into another. In some cases these changes can take less than ten thousand years, in contrast to the Sun's
hydrogen­burning lifetime of about ten billion years. Consequently, the number of stars currently in these
late stages of stellar evolution is comparatively small.
The goal of our research is to trace how stars progress through these stages until they ultimately
become white dwarfs. However, there are major difficulties. For most stars, we do not know how far
away they are or precisely how large, luminous or massive they are. Secondly, we cannot look inside stars
in order to deduce what chemical changes have taken place. We therefore use a variety of indicators,
including the chemical composition of the stellar surface, pulsational properties, and binary companions
to deduce this information.
The surfaces of extreme helium giants --- very luminous stars devoid of hydrogen -- carry a `fossil
record' of the star's previous evolution. An analysis of three such stars, begun in 1997 with the help of
summer students Hamill and Jeffers, demonstrated the oxygen and carbon­rich nature of these stars and
pointed to large­scale mixing between the surface and a highly­processed interior, these changes occurring
sometime in the recent past. This work also led to the improvement of the modelling software used in
the analysis and will be crucial in future research at Armagh.
Extreme helium giants evolve rapidly and pulsate. Measurements of their spectra in ultraviolet
light are sensitive to small changes in temperature. An analysis of about 150 spectra obtained with the
International Ultraviolet Explorer (IUE) was begun with the help of summer student Starling and showed
that measurable changes are taking place in a number of helium giants.
The extremely helium­rich subdwarf V652Her was studied intensely. A chemical analysis proved
that its surface is predominantly nitrogen­rich, pointing to an evolution quite distinct from that of the
helium giants. New observations were obtained with the William Herschel Telescope and will lead to a
very accurate description of its pulsation properties, whilst a theoretical study of its pulsations provided
additional new insights. Meanwhile, new theoretical models of pulsation in this and other helium­rich
subdwarfs identified a potential new class of variable star.
Extreme helium stars and helium­rich subdwarfs are examples of a larger class of stellar remnant
broadly identified as hot subdwarfs. Previous work, with Drilling and others, on the spectral classification
of hot subdwarfs has continued. Just as the Hertzsprung­Russell diagram for normal stars eventually
helped to explain the evolution of young stars, the classification diagram for subdwarfs will help to
explain the evolution of stellar remnants. Simon Jeffery and Ph.D. student Pilar Monta~n'es Rodr'iguez
began to calibrate the classification diagram using model atmospheres.
8

The origin of the largest class of hot subdwarf --- the subdwarf B stars --- remains a puzzle. Essentially
naked helium cores, red giant stars stripped of their hydrogen­rich outer layers, the method for the
removal of hydrogen is not known. One possibility is that the hydrogen could have been transferred onto
a binary companion. The detection of infrared calcium lines in several sdB stars in 1997 demonstrated the
unambiguous signature of a cool companion. Simon Jeffery and Ph.D. student Regina Aznar Cuadrado
made further observations of sdB binaries in order to measure precise dimensions for both stars.
Much of this work is part of an ongoing programme with substantial results on V652Her due for early
completion, and other theoretical work and new observations already carried out.
Other activities included:
1. Telescope time and research grants: observations of binary and pulsating subdwarf B stars were
made with the Isaac Newton and William Herschel Telescopes in La Palma. A PPARC research
grant awarded for studies of pulsations in stellar remnants and announced in late 1998, will provide
for a 3­year postdoctoral position, commencing 1999 July.
2. Collaborative visits, conferences, and talks: a parallel session was organised and a presentation
made on spectral analysis at the National Astronomy Meeting held in St Andrews in March 1998.
Collaborative research visits were made to Japan (under the auspices of a 3­year British Council
award) and to La Palma, to work with colleagues Hideyuki Saio and Don Pollacco. Colloquia were
given on both occasions.
3. PUS: The Armagh Astropark interpretation project progressed to the completion of designs for 5
display panels (now installed in the Astropark). Copies of these panels are included in Appendix G.
This work was supplemented by a project to refurbish the interior of the Schmidt telescope dome
to make it accessible to visitors and to provide an area for scientific displays (realised with the
assistance of summer students Marshall and Tipper). Simon Jeffery also made a presentation of
new results on the origin of gamma­ray bursts and wrote invited articles for popular astronomy
magazines on the evolution of stars and on the origin of water on the Moon. He attended a
PPARC­funded training course on Science and the Media.
6.7 M.D. Smith, Research Astronomer
Dr Michael Smith has focused mainly on the earliest stages of stellar evolution: the processes leading to
star formation from an initially unstable, collapsing cloud of gas, and the energetic outflows --- jets and
winds --- associated with the formation and early evolution of protostars and pre­main­sequence stellar
objects.
The observed events associated with star formation are related to diverse physical and dynamical
mechanisms. Research has begun in Armagh to determine the relationships between these mechanisms
and hence to uncover how low­mass stars like our Sun, as well as more massive stars, even star clusters
and stellar systems, form.
The basic building sites for stars are gigantic clouds of cool molecules. The clouds are in limbo:
their tendency to gravitational collapse is held up by strong magnetic fields and turbulent motions. The
turbulence, revealed by spectroscopic observations, takes the form of chaotic motions at speeds exceeding
the speed of sound. The balance is crucial to the appearance of our Universe; without it, the rate at
which stars form would be (or, more correctly, would have been) about 30 times faster.
We have ideas about what may be the source of the turbulence (internal jet streams, external shock
waves, stellar winds or the Galactic shear) but progress has been hampered by our ignorance of this
brand of turbulence: supersonic molecular magnetohydrodynamics. Together with colleagues Mac Low
(New York) and Burkert (Heidelberg), we have employed numerical simulations to show that all forms
of turbulence decay extremely fast. A range of Mach numbers and magnetic energies has been explored,
from which the need for the turbulence to be constantly regenerated has been concluded.
In contrast to our everyday experiences with gases and fluids, magnetic fields are almost frozen into
the star­forming material. The pressure of the magnetic field must eventually be relieved if the embryonic
star, or `protostar', is to arise. Michael Smith is studying how this occurs. It turns out that the field can
gradually slip out of the denser clumps of molecules by a process called ambipolar diffusion (a decoupling
process: charged ions become rare, and the neutral molecules then slip between them). Alternatively,
the magnetic lines of force can reconnect into new configurations which allow the magnetic pressure to
escape or to change form.
At first, a protostar is extremely difficult to detect. It is deeply embedded in its parent molecular cloud,
totally obscured at infrared wavelengths as well as in the visible. Spectacular jets of molecules, however,
9

betray its presence. Such jets have been observed emanating from the very youngest protostars. We have
been engaged in discovering the cause of the jets and their effects on the parental clouds. Michael Smith
has undertaken numerical experiments, using a molecular hydrodynamics code, to try to understand some
of the observed structures. The project involves Yorke (Jet Propulsion Laboratory, California), Zinnecker
(Potsdam) and students V¨olker and Suttner (W¨urzburg). A major aim is to disentangle environmental
and protostellar factors. Three­dimensional simulations demonstrate the consequences of jet dynamics:
precession, pulsation, shear and spray.
It has recently been recognised that the respective evolution of the jets emitted from the protostar and
the reservoirs of accumulated ejected gas (termed the `bipolar outflows') could evolve synchronously with
that of the protostar, the surrounding accretion disc, and the residual cloud (termed the `envelope'). An
attempt has been made to unify these basic components within a simple model framework. The model
makes the least controversial assumptions to derive the relationships between outflow mechanics, jet
dynamics and protostellar luminosity. Stages in jet behaviour are thus recognisable, as well as diagnostics
for the age of an outflow. The model also emphasizes our lack of understanding: the high rate at which
energy is liberated and momentum is transferred into the bipolar outflow requires a remarkably efficient
mechanism for jet formation.
Other activities and results during 1998 are summarised as follows:
1. detection of hot molecules with the Infrared Space Observatory; distinguishing shock and fluorescent
excitation in DR 21; and constructing infrared and submillimetre maps of the high­mass outflow
W75N, a gigantic outflow generated in the wakes of bow shocks.
2. Michael Smith has also been involved in preliminary discussions concerning the formation of a
European­wide Star Formation Network, and has given seminars on the subject of stellar jets at
the University of Newcastle and at the Armagh meeting of the Astronomical Science Group of
Ireland.
3. Future research in this area will continue with an intensified observational programme employing
ISO data and new infrared data to understand individual outflows, and with a new focus on star for­
mation on larger scales, namely the galactic­size `Starbursts' seen in external galaxies. In addition,
Michael Smith and Mac Low (New York) will study ambipolar diffusion employing new numerical
and analytical techniques, and will examine in detail the formation of bow shock waves and the
fragmentation caused by unstable behaviour which leads to current sheets.
6.8 M.E. Bailey, Director
Professor Mark Bailey completed work with the former PDRA Vacheslav Emel'yanenko on the capture of
Halley­type comets from the long­period cometary flux. He also completed a paper with Ph.D. student
Scott Manley on collision probabilities between small solar system bodies, and together with PDRA David
Asher and visiting research fellow Vacheslav Emel'yanenko provided the explanation for the unexpected
outburst of Leonid fireballs on the morning of 1998 November 17. M.Phil. student Sandra Jeffers began
a study of the size and number distribution of potential projectiles in the inner solar system that may,
by physical collision with comets, dominate the process of cometary physical evolution.
The motivation for investigating the dynamical capture of Halley­type comets bears on the long­
standing question of the origin of short­period comets, defined to be those with periods P !200 yr. There
are fundamentally two different types of short­period comet: those with periods P ! 20 yr, referred to
as Jupiter­family comets; and those with slightly longer periods 20 ! P ! 200 yr, called Halley­types.
The Jupiter­family comets, it appears, largely originate from orbits resembling those of a class of objects
called Centaurs, a group of objects which move through the outer planetary system (roughly between
Saturn and Neptune) in low­inclination orbits, and which in turn are believed to derive largely from a
belt or disc of objects beyond Neptune, known as the Edgeworth­Kuiper belt.
Halley­types, on the other hand, are produced as a result of planetary perturbations acting on initially
very long­period cometary orbits originating in the Oort cloud, a vast nearly spherical cometary reservoir
extending roughly halfway to the nearest star. Given the observed long­period flux, the calculated
transfer probability from such an orbit to a Halley­type orbit, and the dynamical lifetime of the latter,
it is straightforward to predict the number of observed Halley­type objects.
The calculated result, however, is at least two orders of magnitude too large. Therefore, either the
observed Halley­type sample is enormously incomplete (for example, the comets could be covered with
a layer of very dark, insulating material, and therefore be not easily found), or the comets must be
destroyed by some process during their dynamical evolution, possibly disintegrating to dust.
10

Either of these possibilities presents new avenues for research. For example, if the Halley­type objects
are simply very dark, essentially asteroidal in form, then their absolute numbers in space are sufficiently
high as to dominate the terrestrial cratering rate for objects larger than ¸5--10 km in diameter. On the
other hand, if these Halley­type `asteroids' do not exist, the structure of the meteoroid streams produced
by the disintegration of Halley­type comets becomes an even more urgent problem to address.
These arguments led to research publications on the nature and origin of the dominant impactors on
the Earth, the implications for the resulting impact hazard to civilization, and the collision probabilities of
comets and asteroids with respect to the terrestrial planets and other objects. The work carried out with
Asher & Emel'yanenko provided an exceptionally interesting confirmation of the complex structure of
meteoroid streams produced by Halley­type comets, in this case the Leonid meteoroid stream associated
with comet 55P/Tempel­Tuttle.
In addition to astronomical research, M.E. Bailey attended several conferences (e.g. the Thessaloniki
International Seminar on Current Issues of Astronomical and Planetary Concern, 1998 April; and the
ESO (Garching) conference on Minor Bodies in the Outer Solar System, 1998 November), and presented
a large number of seminars and public talks, notably at the Seventh European Astrofest meeting (Kens­
ington, 1998 January), at the Thessaloniki meeting, and to astronomical societies in the UK and Ireland.
Many press, radio and television interviews were carried out, including appearances in several television
documentaries concerning comets and asteroids.
7 Public Understanding of Science
7.1 Press, Radio, Television and Film
Following two years aided by the appearance of unusually bright comets (Hyakutake in 1996 and Hale­
Bopp in 1997), the Observatory might be excused for making a reduced public impact in 1998. In fact,
however, staff were in even greater demand to express a professional opinion about one or another new
result in astronomy, and often made the news concerning aspects of their own research. The number of
identified media mentions in 1998 (namely 147) is up by almost 40% compared to the equivalent number
(108) noted in 1997, itself a substantial improvement on the 45 in 1996. The Observatory can now
expect an average of at least one substantial (i.e. national) media mention per week, and is the leading
professional point of contact for astronomy in both Northern Ireland and the Republic of Ireland.
From time to time the Observatory also issues press releases on meteorological and astronomical topics
of local or general interest, and on news items that specifically concern Armagh Observatory staff or their
research results. In 1998, the Librarian issued 28 such media releases, of which at least 22 were published
in the local or national press in one form or another, an extremely high `hit' rate. The Librarian (and
occasionally other staff too) also answers many requests from members of the public on different aspects
of astronomy, the list of ¸180 such requests during 1998 being included for information in Appendix F.
Looking to the future, the Librarian produced a solar eclipse leaflet in readiness for the 1999 August
11 total solar eclipse, the first such total solar visible from the UK mainland for two generations. This
leaflet, also available from the Observatory's web­page (http://www.arm.ac.uk/eclipse99.html), has been
in much demand.
7.2 Astropark
Dr Simon Jeffery, working with the assistance of summer students, has produced the first of a number of
fine display panels to be placed in the Armagh Astropark, illustrating various aspects of astronomy and
of the exhibits on view there. Copies of these display panels are included for information in Appendix G.
The Observatory is committed to developing and improving the facilities in the Armagh Astropark, and
will seek to improve this public facility as and when time and other resources allow.
7.3 Heritage
The Armagh Observatory is a unique establishment, and continues to flourish as a working astronomical
observatory on its original site. The history of the Observatory encompasses the whole of modern as­
tronomy, while the Georgian Grade A listed building, with its many unique and distinctive architectural
features, houses one of the most valuable scientific archives and book collections in Northern Ireland.
The Observatory also has an important collection of historic instruments and other documents, which
can be used to illustrate the wide range of scientific work carried out at the Observatory for more than
200 years, from the late 18th century to the present.
11

These are important assets, and the Governors of the Armagh Observatory and Planetarium have an
unrivalled opportunity to develop a centre for the public understanding of science, explaining the history
and motivation for the development of astronomy and related sciences over more than 200 years, and the
context in which present research is carried out. The Observatory is currently investigating possibilities
for obtaining Heritage Funding to develop this side of its activities, the proposal to include the restoration
of three of the Observatory's historic telescopes and their domes. This project will be progressed during
1999 and 2000 with the assistance of the architect Stephen Leighton, and David Sinden of the Sinden
Optical Company.
8 Items of Concern
ffl JANET Access: The Observatory continues to require internet access to the Joint Academic Net­
work (JANET) on the same basis as UK university departments. The present arrangement, namely
a `sponsored connection' with the Queen's University of Belfast (QUB), provides a bandwidth of
only 256 kbps. This is barely sufficient for current requirements and does not provide a long­term
solution to the needs of a modern astronomical research institute into the next millennium, par­
ticularly in the light of increasing use of the internet world­wide. A cost­effective 2Mbps primary
connection to JANET would require an uplift in funding of ¸$35k per year.
ffl It is notable that the Observatory operates with a very high ratio of core research activities to
the cost of administrative and support staff, and with a similarly successful ratio of external grant
income to DENI grant­in­aid. Further economies of scale, consolidation of the present high level of
research activity, and further increases in external income would be achievable were the DENI to
invest in additional research infrastructure and research staff positions.
ffl DENI Recurrent Grant­in­Aid: increases in the DENI grant continue to fall substantially behind
rising costs, as indicated in the following Table 1. The results described in this report have been
achieved against a background of a reduction in real funding levels; the level of research output and
external income generation are unlikely to be sustainable if such cuts continue. Were the DENI
to reward success and provide the Observatory with a stable funding regime, much more could be
achieved.
Total DENI DENI Income External Refereed
Financial Year Grant­in­Aid Normalised to Grant Income Journal
($000s) 1993/1994 prices ($000s) Publications
1993/1994 445.0 445.0 35 13
1994/1995 425.6 414.9 58 22
1995/1996 468.5 442.1 172 19
1996/1997 480.0 442.3 264 45
1997/1998 473.2 425.7 275 42
1998/1999 443.0 383.1 195 43
Table 1: DENI grant­in­aid over the years. The third column shows the value of the announced grant­
in­aid for each financial year normalised to 1993/1994 prices, the values corrected for rising costs by
the Retail Prices Index. The number of refereed publications refers to the corresponding calendar year
(e.g. publications in financial year 1998/1999 corresponds to calendar year 1998). It is notable that the
total external income in 1998/1999 was $213k. The DENI grant­in­aid for 1999/2000 was announced at
$458.5k (equivalent to $390.2k at 1993/1994 prices).
12

A Armagh Observatory Staff, 1998
Title, Name and Starlink Username Position Notes Base Cost
Centre
1 Professor Mark E. Bailey meb Director OBS OBS
2 Dr C. John Butler cjb Research Astronomer OBS OBS
3 Dr John E. Chambers jec Research Astronomer OBS OBS
4 Dr J. Gerry Doyle jgd Research Astronomer OBS OBS
5 Dr C. Simon Jeffery csj Research Astronomer OBS OBS
6 Dr Michael D. Smith mds Research Astronomer OBS OBS
7 Dr Bill M. Napier wmn Senior Research Fellow OBS OBS
8 Dr Mart J.H. de Groot mdg Senior Research Associate Retired Home OBS
9 Mr Geoff Coxhead gc Software/Hardware Support OBS OBS
10 Mr H. Martin Murphy hmm Starlink Manager OBS OBS
11 Mrs Margaret Cherry mc Accounts Officer OBS OBS
12 Mr John McFarland jmf Librarian/PRO/Archivist OBS OBS
13 Mrs Aileen McKee ambn Secretary/Admin. Support OBS OBS
14 Mr Lawrence F. Young lfy Joint Administrator OBS/PLA OBS/PLA
15 Grounds/Meteorological Officer Post Vacant OBS OBS
16 Assistant Groundsman Post Vacant OBS OBS
17 Dr David J. Asher dja PDRA PPARC OBS OBS
18 Dr Dipankar Banerjee dipu PDRA PPARC OBS OBS
19 Mr Darko Jevremovi'c djc PDRA PPARC OBS OBS
20 Dr Alex J.R. L¨obel ajrl PDRA OBS OBS
21 Dr Armin Theissen ath PDRA PPARC OBS OBS
22 Dr S. Victor M. Clube svmn Visiting Research Fellow Home OBS
23 Ms Sandra V. Jeffers svj Research Student (MPhil) F/T QUB OBS OBS
24 Ms Regina Aznar Cuadrado rea Research Student (PhD) P/T QUB OBS OBS
25 Mr Enric Pall'e Bag'o epb Research Student (PhD) P/T QUB OBS OBS
26 Mr Scott P. Manley spm Research Student (PhD) P/T QUB OBS OBS
27 Mr Kassios Mitrou kam Research Student (PhD) P/T Athens Athens Self
28 Mr Ferhat F. Ozeren ffo Research Student (PhD) F/T Ankara OBS OBS
29 Ms Elena P'erez P'erez epp Research Student (PhD) P/T QUB OBS OBS
30 Ms Pilar Monta~n'es Rodr'iguez pmr Research Student (PhD) P/T QUB OBS OBS
31 Mr Il'ia Iankov Roussev ilr Research Student (PhD) P/T QUB OBS OBS
32 Mr Jim V. Scotti jvs Research Student (PhD) P/T QUB Tucson OBS
33 Mr P. Nick Sleep Research Student (PhD) P/T Open Univ. Home Self
34 Mr Luca Teriaca lte Research Student (PhD) P/T QUB OBS OBS
Armagh Observatory staff position at 1998 December 31.
13

B Refereed Journal Publications, 1998
1. Asher, D.J., Steel, D.I., 1998, ``On the possible relation between the Tunguska bolide and Comet
Encke'', Planet. Space Sci. 46, 205--211.
2. Asher, D.J., Izumi, K., 1998, ``Meteor observations in Japan: new implications for a Taurid
meteoroid swarm'', MNRAS 297, 23--27.
3. Asher, D.J., Clube, S.V.M., 1998, ``Towards a dynamical history of `proto­Encke''', Cel. Mech.
Dyn. Astron. 69, 149--170.
4. Bagnulo, S., Doyle, J.G., Andretta, V., 1998, ``Observations and modelling of spectral energy
distributions of carbon stars with optically thin envelopes'', MNRAS 296, 545--563.
5. Banerjee D., 1998, ``Magnetoatmospheric oscillations in flux tubes'', IAJ 25, 113--118.
6. Banerjee, D., Teriaca, L., Doyle, J.G., Wilhelm, K., 1998, ``Broadening of Si VIII lines observed
in the solar polar coronal holes'', A&A 339, 208--214.
7. Butler, C.J., Coughlin, A.D.S., Fee, D., 1998, ``Precipitation at Armagh Observatory 1838--
1997'', Proc. Roy. Irish Acad. Biology and Environment 96B, 123--140.
8. Byrne, P.B., Abdul Aziz, H., Amado, P.J., Arevalo, M.J., Avgoloupis, S., Doyle, J.G., Eibe,
M.T., Elliott, K.H., Jeffries, R.D., Lanzafame, A.C., Lazaro, C., Murphy, H.M., Neff, J.E., Panov,
K.P., Sarro, L.M., Seiradakis, J.H., Spencer, R.E., 1998, ``The photosphere and chromosphere of
the RS Canum Venaticorum star, II Pegasi. II. A multi­wavelength campaign in August/September
1992'', A&AS 127, 505--519.
9. Chambers, J.E., Wetherill, G.W., 1998, ``Making the terrestrial planets: N­body integrations of
planetary embryos in three dimensions'', Icarus 136, 304--327.
10. Corradi, R.L.M., Aznar, R., Mampaso, A., 1998, ``Orientation of planetary nebulae within the
Galaxy'', MNRAS 297, 617--623.
11. Coughlin, A.D.S., Butler, C.J., 1998, ``Is urban spread affecting meteorological observations at
Armagh Observatory?'', IAJ 25, 125--128.
12. Davis, C.J., Smith, M.D., Moriarty­Schieven, G.H., 1998, ``A textbook case of bow shock entrain­
ment in a YSO outflow'', MNRAS 299, 825--833.
13. di Martino, M., Carusi, A., Dotto, E., Lazzarin, M., Marzari, F., Migliorini, F., 1998, ``Dynamical
and physical properties of comet­asteroid transition objects'', A&A 329, 1145--1151.
14. Doyle, J.G., Banerjee, D., Perez, M.E., 1998, ``Coronal line­width variations'', Solar Phys.
181, 91--101.
15. Doyle, J.G., Short, C.I., Byrne, P.B., Amado, P.J., 1998, ``Chromospheric and coronal
activity levels in the nearby faint M dwarf Gl 105B'', A&A 329, 229--232.
16. Doyle, J.G., van den Oord, G.H.J., O'Shea, E., Banerjee, D., 1998, ``Waves in the solar
transition region'', Solar Phys. 181, 51--71.
17. Drilling J.S., Jeffery C.S., Heber U., 1998, ``Spectral analysis of the extreme helium star LSS 3184''
A&A 329, 1019--1027.
18. Erd'elyi, R., Doyle, J.G., Perez, M.E., Wilhelm, K., 1998, ``Center­to­limb line width measure­
ments of solar chromospheric, transition region and coronal lines'', A&A 337, 287--293.
19. Emel'yanenko V.V., Bailey M.E., 1998, ``Capture of Halley­type comets from the near­parabolic
flux'' MNRAS 298, 212--222.
20. Gunn, A.G., Mitrou, C.K., Doyle, J.G., 1998, ``On the rotation­activity correlation for active
binary stars'', MNRAS 296, 150--164.
21. Harris N.W., Bailey M.E., 1998, ``Dynamical evolution of cometary asteroids'', MNRAS 297,
1227--1236.
15

22. Hecht J.H., Clayton G.C., Drilling J.S., Jeffery C.S., 1998, ``Ultraviolet Observations of the hot
R Coronae Borealis­type star V348 Sagitarii during a deep minimum'', ApJ 501, 813--822.
23. Jeffery C.S. 1998, ``Spectral analysis of the high­gravity extreme helium star LSIV+6 ffi 2'', MNRAS
294, 391--398.
24. Jeffery C.S., Hamill P.J., Harrison P.M., Jeffers S.V., 1998, ``Spectral analysis of the low­gravity
extreme helium stars LSS 4357, LS II+33 ffi 5 and LSS 99'', A&A 340, 476--482.
25. Jeffery C.S., Pollacco D.L., 1998, ``The detection of binary companions to subdwarf B stars'',
MNRAS 298, 179--184.
26. Jevremovi'c, D., Butler, C.J., Drake, S.A., O'Donoghue, D., van Wyk, F., 1998, ``Ultraviolet
and optical flares on Gl 866'', A&A 338, 1057--1065.
27. Mac Low, M.­M., Klessen, R.S., Burkert, A., Smith, M.D., 1998, ``Kinetic energy decay rates of
supersonic and super­Alfv'enic turbulence in star­forming clouds'', Phys. Rev. Lett., 80, 2754--2757.
28. Manley, S.P., Migliorini, F., Bailey, M.E., 1998, ``An algorithm for determining collision
probabilities between small solar system bodies'', A&AS 133, 437--444.
29. Migliorini, F., Michel, P., Morbidelli, A., Nesvorn'y, D., Zappal`a, V., 1998, ``Origin of multikilo­
meter Earth and Mars­crossing asteroids: a quantitative simulation'', Science, 281, 2022--2024.
30. Moons, M., Morbidelli, A., Migliorini, F., 1998, ``Dynamical structure of the 2/1 commensurability
with Jupiter and the origin of the resonant asteroids'', Icarus, 135, 458--468.
31. Napier, W.M., 1998, ``NEOs and impacts: the Galactic connection'', Cel. Mech. Dyn. Astron.
69, 59--75.
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17

C Armagh Observatory Seminars, 1998
Date
Speaker
Affiliation
Title
Wed
21
Jan
1998
D.
Jevremovic
Armagh
Balmer
Decrements
as
Diagnostics
of
Stellar
Flare
Plasma
Wed
4
Feb
1998
A.
Lobel
Armagh
Long­Term
High­Resolution
Spectroscopy
of
the
Cool
Hypergiant
Rho
Cassiopeiae
Wed
18
Feb
1998
T.
Mason
Armagh
Planetarium
The
Belleek
Event
Wed
25
Feb
1998
M.E.
Bailey
Armagh
NEO
Hazards:
Dynamical
Constraints
on
Impactor
Populations
Wed
4
Mar
1998
S.P.
Manley
Armagh
Collisions
in
the
Solar
System
Thu
12
Mar
1998
F.
Murtagh
University
of
Ulster
Environmental
and
Climatic
Modelling
of
Relevance
to
Astronomy
Wed
25
Mar
1998
D.
Campbell
Meteorological
Office,
Belfast
The
Climate
of
Northern
Ireland
Wed
8
Apr
1998
D.
Lynden­Bell
Queen's
University
Belfast
Extraordinary
N­Body
Problems
Wed
22
Apr
1998
J.
Venables
Meteorological
Office,
Aldergrove
Weather
Forecasting
Wed
6
May
1998
C.
Ruggles
Leicester
and
QUB
Prehistoric
Astronomy
in
Ireland
and
Britain
Wed
13
May
1998
L.
Teriaca
Armagh
Redshifts
in
the
Solar
Chromosphere
and
Transition
Region:
Observation
and
Analysis
Wed
13
May
1998
R.
Aznar
Armagh
The
Evolutionary
Status
of
Subdwarf
Binaries
Wed
20
May
1998
P.
Dufton
QUB
Chemical
Composition
of
Our
Own
and
Other
Galaxies
Wed
27
May
1998
I.
Banks
Ballynahinch
Men's
Health
and
Risk
Taking
Tue
2
Jun
1998
J.
Cohen
NRAL,
Jodrell
Bank
Magnetic
Fields
in
OH
Maser
Regions
Wed
3
Jun
1998
I.
Sanders
Trinity
College
Dublin
Meteorites
as
Constraints
on
Astrophysical
Models
for
Nebular
Processes
Tue
9
Jun
1998
S.
Bagnulo
University
of
Vienna,
Austria
Modelling
of
Magnetic
Fields
of
Chemically
Peculiar
Stars
Wed
10
Jun
1998
D.
Roscoe
University
of
Sheffield
Mach's
Principle
Revisited:
A
Quasi­Fractal
Universe
and
its
Dynamics
Wed
24
Jun
1998
H.
Pretka
Astronomical
Observatory,
Poznan
Planetary
and
Galactic
Perturbations
in
the
Motion
of
One­Apparition
Comets
Wed
1
July
1998
J.E.
Chambers
Armagh
Symplectic
Integrators
---
a
New
Way
to
Make
Planets
Wed
8
Jul
1998
D.
Pollacco
Isaac
Newton
Group,
La
Palma
Planetary
Nebulae
and
their
Central
Stars,
including
Sakurai's
Object,
a
Recent
Born­Again
Red
Giant
Wed
15
Jul
1998
B.
Miller
Leiden
Observatory
Globular
Clusters
and
the
Evolution
of
Elliptical
Galaxies
Tue
21
Jul
1998
R.
Walsh
University
of
St.
Andrews
Bright
Tangles
on
the
Sun:
Heating
Active
Region
Loops
Wed
22
Jul
1998
J.
Nuth
III
NASA
Goddard
Space
Flight
Center
Silicate
Annealing,
Herbig
AeBe
Stars
and
the
Formation
of
Comets
Wed
29
Jul
1998
I.
Bonnell
Institute
of
Astronomy,
Cambridge
Star
Formation
in
Clusters
Wed
9
Sep
1998
S.V.M.
Clube
Department
of
Physics,
Oxford
J.H.
Oort
and
the
Oort
Cloud
Wed
16
Sep
1998
D.J.
Asher
Armagh
Approach
Directions
of
Colliding
Asteroids
Wed
23
Sep
1998
D.
Banerjee
Armagh
Dynamical
Nature
of
the
Quiet
Solar
Atmosphere
Thu
29
Oct
1998
A.G.
Gunn
NRAL,
Jodrell
Bank
SETI
Observations
at
Jodrell
Bank
Fri
30
Oct
1998
S.
Isobe
National
Astron.
Observatory,
Japan
The
Japanese
Near­Earth
Object
Telescope
Project
Mon
16
Nov
1998
Nine
Speakers
Armagh
and
Beyond
One­Day
Solar
SystemWorkshop
Wed
25
Nov
1998
J.
McFarland
Armagh
An
Armchair
Tour
of
Armagh
Observatory
Wed
2
Dec
1998
A.
L¨
obel
Armagh
Modelling
the
Spectral
Energy
Distribution
and
Variability
of
Asymptotic
Giant
Branch
Stars
Seminars
at
Armagh
Observatory,
calendar
year
1998.
Organized
by
A.D.S.
Coughlin
and
D.
Banerjee.
18

D Talks by Armagh Observatory Staff, 1998
Date
Speaker
Location
Title
1998
J.
McFarland
Armagh
Observatory
66
Tours
of
Armagh
Observatory
given
in
1998
Wed
21
Jan
1998
D.
Jevremovic
Armagh
Observatory
Balmer
Decrements
as
Diagnostics
of
Stellar
Flare
Plasmas
Wed
21
Jan
1998
W.M.
Napier
Rutherford
Appleton
Laboratory
Quantized
Redshifts
Fri
30
Jan
1998
M.E.
Bailey
Seventh
European
AstroFest,
Kensington,
London
The
Threat
from
Space
Sat
31
Jan
1998
M.E.
Bailey
Seventh
European
AstroFest,
Kensington,
London
Comet
Hale­Bopp:
Origin
and
Dynamical
Evolution
Wed
4
Feb
1998
A.
L¨
obel
Armagh
Observatory
Long­Term
High­Resolution
Spectroscopy
of
the
Cool
Hypergiant
Rho
Cassiopeiae
Fri
6
Feb
1998
M.E.
Bailey
Irish
Physics
Student
Association
Meeting,
QUB
The
Increasing
Threat
from
Space
Wed
25
Feb
1998
M.E.
Bailey
Armagh
Observatory
NEO
Hazards:
Dynamical
Constraints
on
Impactor
Populations
Wed
4
Mar
1998
S.P.
Manley
Armagh
Observatory
Collisions
in
the
Solar
System
Mon
23
Mar
1998
M.E.
Bailey
Lurgan
Rotary
Club
Research
at
Armagh
Observatory
Apr
1998
J.E.
Chambers
Lisburn,
Portugal
N­Body
Simulations
of
Planet
Formation
Mon
6
Apr
1998
M.E.
Bailey
Thessaloniki,
Greece
The
Threat
from
Space:
Dynamical
Constraints
on
Impactor
Populations
Mon
6
Apr
1998
M.E.
Bailey
Thessaloniki,
Greece
Origin
of
Comets
and
the
Evolution
of
the
Oort
Cloud
Fri
17
Apr
1998
M.E.
Bailey
ASGI
Meeting,
Cork
The
Impact
Hazard:
Source
Populations
and
Dynamical
Constraints
Fri
17
Apr
1998
W.M.
Napier
ASGI
Meeting,
Cork
Galactic
Dark
Matter
and
the
Marine
Fossil
Record
Mon
27
Apr
1998
M.E.
Bailey
TCD
Astronomy
&
Space
Society,
Dublin
The
Threat
from
Space:
Dynamical
Constraints
on
Impactor
Populations
May
1998
J.E.
Chambers
London
Planetary
System
Formation
Theory
Mon
11
May
1998
C.S.
Jeffery
Armagh
Rotary
Club
Gamma­Ray
Bursts
Wed
13
May
1998
R.
Aznar
Armagh
Observatory
The
Evolutionary
Status
of
Subdwarf
Binaries
Wed
13
May
1998
L.
Teriaca
Armagh
Observatory
Redshifts
in
the
Solar
Chromosphere
and
Transition
Region:
Observation
and
Analysis
Jun
1998
J.E.
Chambers
University
of
Durham
Making
the
Terrestrial
Planets
Fri
5
Jun
1998
M.E.
Bailey
Queen
Mary
and
Westfield
College,
London
Impacts
of
Minor
Bodies
with
the
Earth
Sun
21
Jun
1998
M.E.
Bailey
IAA
Solstice
Spectacular,
Armagh
Planetarium
The
Increasing
Threat
from
Space
Presentations
by
Armagh
Observatory
staff,
1998
January
1
to
1998
June
30.
19

Date
Speaker
Location
Title
Jul
1998
J.E.
Chambers
Namur,
Belgium
A
Symplectic
Integration
Scheme
that
Allows
Close
Encounters
between
Massive
Bodies
Wed
1
Jul
1998
J.E.
Chambers
Armagh
Observatory
Symplectic
Integrators:
A
New
Way
to
Make
Planets
Wed
1
Jul
1998
M.
de
Groot
Salzburg,
Austria
The
Origin
of
the
Universe
Wed
8
Jul
1998
M.
de
Groot
Jongny,
Switzerland
The
Future
of
the
Universe
Tue
21
Jul
1998
M.D.
Smith
Jena,
Germany
Turbulence,
Protostars
and
Jets
Thu
30
Jul
1998
M.D.
Smith
Max
Planck
Institut
f¨ ur
Radioastronomie,
Bonn
The
Unification
Scheme
Thu
20
Aug
1998
W.M.
Napier
IAU
Symposium
No.
194,
Armenia
Quantized
Redshifts:
New
Physics
or
Old
Muddle?
Mon
24
Aug
1998
M.D.
Smith
Bad
Honnef,
Germany
Protostellar
Outflows
Sep
1998
C.S.
Jeffery
Tohoku
University,
Sendai,
Japan
Stellar
Remnants:
Chemical
Evolution
and
Binary
Companions
Sep
1998
C.S.
Jeffery
Isaac
Newton
Group,
La
Palma,
Spain
Stellar
Remnants:
Chemical
Evolution
and
Binary
Companions
Mon
7
Sep
1998
C.J.
Butler
British
Society
of
Soil
Scientists,
GlobalWarming:
Man
or
Nature?
Department
of
Agriculture,
Belfast
Wed
9
Sep
1998
J.
McFarland
Meeting
of
the
UK
Eclipse
Education
and
Solar
Eclipse
of
11
August
1999
Coordination
Working
Group,
BAAS,
Cardiff
Sun
13
Sep
1998
S.P.
Manley
EADN
Summer
School
on
Solar
and
Extrasolar
Planets
Collision
Probability
Determination
Wed
16
Sep
1998
D.J.
Asher
Armagh
Observatory
Approach
Directions
of
Colliding
Asteroids
Sun
20
Sep
1998
W.M.
Napier
Whirlpool
Star
Party,
Birr
Big
Bang
Cosmology
Wed
23
Sep
1998
D.
Banerjee
Armagh
Observatory
Dynamical
Nature
of
the
Quiet
Solar
Atmosphere
Oct
1998
J.E.
Chambers
DPS
Meeting,
Madison,
Wisconsin
How
Special
is
the
Earth's
Orbit?
Fri
9
Oct
1998
D.J.
Asher
Royal
Astronomical
Society,
London
Historical
Variability
of
the
Interplanetary
Complex
Sat
10
Oct
1998
M.E.
Bailey
Open
University
Graduate
Day,
Milton
Keynes
Orbital
Evolution
of
Small
Bodies
in
the
Solar
System
Sat
10
Oct
1998
M.E.
Bailey
Runnymede
Astronomical
Society,
Maidenhead
Populations
of
Impacting
Objects
Tue
13
Oct
1998
M.D.
Smith
Heidelberg,
Germany
The
Unification
Scheme
Wed
21
Oct
1998
D.J.
Asher
Irish
Astronomical
Association,
Belfast
Astrometry
of
Near­Earth
Objects
Thu
22
Oct
1998
C.S.
Jeffery
ASGI
Meeting,
QUA,
Armagh
The
Pulsating
Helium
Star
V652Her
Thu
22
Oct
1998
M.D.
Smith
ASGI
Meeting,
QUA,
Armagh
Protostellar
Outflows
Thu
5
Nov
1998
M.E.
Bailey
ESO
Conference
Garching,
Germany
Minor
Bodies
in
the
Outer
Solar
System:
Conference
Summary
Mon
9
Nov
1998
W.M.
Napier
Armagh
Rotary
Club
Nemesis
Thu
12
Nov
1998
M.D.
Smith
University
of
Newcastle
Numerical
Simulations
of
Jets
Mon
16
Nov
1998
J.E.
Chambers
Armagh
Observatory
Circumstellar
Discs
Wed
25
Nov
1998
J.
McFarland
Armagh
Observatory
An
Armchair
Tour
of
Armagh
Observatory
Thu
26
Nov
1998
M.D.
Smith
Max
Planck
Institut
f¨ ur
Astronomie,
Heidelberg
The
Inflow­Outflow
Questions
Dec
1998
J.E.
Chambers
University
of
Oxford
Making
the
Terrestrial
Planets
Wed
2
Dec
1998
A.
L¨
obel
Armagh
Observatory
Modelling
the
Spectral
Energy
Distribution
and
Variability
of
Asymptotic
Giant
Branch
Stars
Presentations
by
Armagh
Observatory
staff,
1998
July
1
to
1998
December
31.
20

E Identified Media Mentions, 1998
21

F Public Queries, 1998
24

G Astropark Display Panels
27

.
14