... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Risks Comparable to NEOs . ... The Increasing Rate of Discovery of Asteroids . ... Comet and Asteroid Collision Probabilities . ... Extreme albedo comets and the impact hazard (PDF Format) . ... Asteroid Impact Animations . ... Workshop on Scientific Requirements for Mitigation of Hazardous Comets and Asteroids - 2002 . ... The Spaceguard Survey Report, 1992 (PDF) . Tsunami from Asteroid/Comet Impacts . ...

Next: Star Formation Rate and Up: No Title Previous: Calculation of Evolutionary Tracks . To start calculations, we choose the distributions of the initial binary parameters: the mass of the primary ZAMS component, , binary mass ratio, , orbital separation a . ... whereas the mass ratio distribution is not. ... The zero assumption often made is that the mass ratio distribution has a flat shape, that is binaries with a high mass ratio occur as frequently as those with equal masses. ...

... Астронет | ... Переменные Звезды | ... Микролинзирование . ... На протяжении последних нескольких лет в рамках проекта MACHO проводятся наблюдения микролинзирования звезд Большого Магелланова Облака - спутника нашей Галактики. Эффект микролинзирования заключается в гравитационной фокусировке света звезды массивным объектом, находящимся на луче зрения между звездой и наблюдателем. ... Согласно некоторым гипотезам, линзами могут являться реликтовые черные дыры или "нейтралинные звезды". ...

... The sample of the Local Volume galaxies (distance smaller than 10 Mpc) gives a unique opportunity to study the properties of galaxies including the weakest objects: the absolute magnitude M B -10 and the virial mass M vir 10 9 M x263C;. ... Luminosity function of the Local Volume galaxies. ... The luminosity functions for galaxies are presented: red dashed line - from the 2dFGRS survey (Norberg et al. 2002); blue dash-dotted line - from the SDSS survey (Blanton et al. ...

... Science . ... Science Users Information > Science and Technical Meetings > Conferences 2010 > Central Massive Objects: The Stellar Nuclei - Black Hole Connection . ... Science Users Information . ... Observing with ESO Telescopes . ... Science Software . ... ESO Science Newsletter . ... An ESO workshop for observers and theorists to discuss recent progress in our understanding of the formation and evolution of black holes and star clusters in the centres of galaxies and their connection to each...

... Since the reddening found for the stars in Table 13 was small, no reddening correction was attempted. ... These diamonds indicate the positions of very low mass, 3 Myr old, objects from the work of Burrows et al. ... This optical V versus R - I scheme is a very powerful method of detecting very low mass (VLM) objects. ... Because of this, young brown dwarfs are intrinsically no more difficult to observe in the optical than low mass stars at the age of Orionis. ...

Some peculiarities of orbits of observed comets. ... Icarus, 2005 Simulation and reality Distribution of anti-perihelia of short-period comets with e 0.9 ( ecliptic coordinates ) Distribution of anti-perihelia of short-period comets with e 0.9 ( ecliptic coordinates ) Distribution of anti-perihelia of long-period comets with 0.9 e 1 ( ecliptic coordinates ) ­ ...

... Up: Data Analysis and Processing Techniques . ... Also, a method for quality control of CCD observations is suggested. ... Everyone who observes a celestial object using a CCD detects moving celestial objects as a ``by product''. ... We hope that our investigations may be useful for near-Earth space control and also for searches of the moving celestial objects through analysis of old and new CCD frames obtained at any amateur or professional astronomical observatory. ...

The magnetic properties of Main Sequence Stars, White Dwarfs and Neutron Stars Lilia Ferrario Mathematical Sciences Institute Australian National University Properties of MWDs High Field MWDs ~ 106 - 109 G (~14% ,Liebert et al. ... 2006). ... Orion also exhibits a highly abnormal massive-star mass function (Pflamm-Altenburg & Kroupa 2006) Origin of magnetic fields Interstellar magnetic fields are trapped in collapsing protostars and survive to the compact star stage (strong fossil field hypothesis). ...

Next: Summary of the present Up: Discussion Previous: Discussion . As shown in Table 1 , among 104 observed emission-line objects 66 (63%) were classified based on the character of their spectra and their absolute magnitudes as H II /BCGs or probable BCGs. Since the main goal of the HSS is an efficient search for new BCGs, the fraction of this type among all confirmed ELGs of the first priority list ( 68 %, or 63 % among all emission-line objects) is encouraging. ...

The H II complex N 44 in the Large Magellanic Cloud (LMC) provides an excellent site to perform a detailed study of star formation in a mild starburst, as it hosts three regions of star formation at different evolutionary stages, and it is not as complicated and confusing as the 30 Doradus giant H II region. We have obtained Spitzer Space Telescope observations and complementary ground-based 4 m uBVIJK observations of N 44 to identify candidate massive young stellar objects (YSOs). ...

In 1950 Jan Oort noticed that . no comet has been observed with an orbit that indicates that it came from interstellar space, . ... From this he proposed that comets reside in a vast cloud at the outer reaches of the solar system. ... Unfortunately, since the individual comets are so small and at such large distances, we have no direct evidence about the Oort Cloud. ... Its orbit is intermediate between the Kuiper Belt and what was previously thought to be the inner part of the Oort Cloud. ...

... Bispectrum Speckle Interferometry of the Massive Protostellar Object S140 IRS 1: Evidence for Multiple Outflows . ... P21W Bispectrum speckle interferometry is emplyed to explore the deeply embedded young stellar object S140 IRS 1 and its environment. ... The diffuse structures around IRS 1 seem to trace the interaction of energetic outflows from IRS 1 with the circumstellar material. ...

... no comet has been observed with an orbit that indicates that it came from interstellar space, . ... From this he proposed that comets reside in a vast cloud at the outer reaches of the solar system. ... Unfortunately, since the individual comets are so small and at such large distances, we have no direct evidence about the Oort Cloud. ... T he Kuiper Belt is a disk-shaped region past the orbit of Neptune roughly 30 to 100 AU from the Sun containing many small icy bodies. ... Small Bodies .. ...

... The object is remarkable because of its low estimated mass and age and because it is associated with a mid-infrared source, an indication of a surrounding dusty disk. Based on the comparison of our spectrum with similar spectra of field M-dwarfs and atmospheric models, we obtain revised estimates of the spectral type, effective temperature and luminosity of the central object. ...

... Events . ... The Event Horizon Telescope: Observing Black Holes with Schwarzschild-Radius Resolution . ... Galaxy lies a super massive black hole - 4 million times more massive . ... Universe to spatially resolve and image a black hole Event Horizon. ... For the much more massive (6 billion solar mass) black hole . ... for assembling a submm-VLBI Event Horizon Telescope. ... emission near the event horizon of super massive black holes. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

Short-Period Comets: Origin and Terrestrial Impact Hazard . ... The model is consistent with the basic observed distributions of near-parabolic comets, short-period comets, Centaurs and high-eccentricity trans-Neptunian objects.This model requires that initial objects in the early Solar System are concentrated to the outer planetary region, and the physical lifetime of comets in the inner planetary region at the present epoch is an increasing function of initial perihelion distances. ...

The radial distribution of metallicity of star-forming galaxies in a galaxy cluster can inform us about the mass assembly and enrichment history of the galaxy cluster. ... Both galaxy clusters are cool-core clusters at redshift z т?? ... The gas-phase metallicity of star- forming galaxies in MACS1115+01 exhibit anti-correlation with projected distance т??0.15 ТБ 0.08 dex/Mpc, whereas the radial metallicity distribution of RXJ1532+30 is statistically flat (т??0.09 ТБ 0.12 dex/Mpc). ...

Dust around Herbig Ae/Be Stars: Porous, Cometary-like Grains? ... This brings up the question, which we try to answer here, of how the grain porosity affects the observational manifestations of the dust shells of HAeBe stars: the excess infrared emission, anomalous extinction in the ultraviolet, and the peculiar behaviour of colour indices and linear polarization during deep brightness minima observed for about 25% of HAeBe stars (UX Ori, WW Vul, etc). ...

AGES observations of Abell1367 and its outskirts Cortese L.1, Minchin R.F.2, Auld R.R.1, Davies J.I.1, Catinella B.2, Momjian E.2, Rosenberg J.L.3, Taylor R.1, Gavazzi G.4, O'Neil K.5 & The AGES Team 1. ... AGES-A1367 Observations Area covered: 5x1 sq. deg. ... Properties of the AGES-A1367 Sample More massive galaxies appear to be redder, have higher surface brightness and lower gas content than dwarf systems, as found in optically selected samples. ...