- 1.
- Observation and modelling of stellar flares: Two observing runs
were undertaken (with D. Jevremovic) 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 time-resolution optical spectrophotometry of a
flare on the nearby active dwarf AD Leo, using a new drift-scan
technique on a CCD. This is believed to be the first time that optical
spectroscopy of a stellar flare has been obtained with a
time-resolution 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. Jevremovic has continued to write up his thesis on the behaviour
of the Balmer lines during stellar flares.
- 2.
- Angular momentum of late-type 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 40-inch Ritchey-Chrétien
Telescope at Siding Spring Observatory received an award of a week in
February 1999.
- 3.
- COROT: Several applications were made for high-dispersion
spectroscopic time on 2-metre 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.
- 4.
- Climatology: A new PhD student, Enric Pallé Bagó, 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 three-day 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 Jevremovic (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 wide-field imaging, if successful,
promises to be a faster route to the end result than the previously
attempted techniques involving high-resolution 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.
