... 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 . ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

... RATAN-600 data for the BL Lacertae objects (multi-frequency catalogue, Version 1.0) . GPS radio sources . ... BL Lacertae objects . ... The difference between these objects is the peak frequency of the synchrotron component of their spectral energy distribution (HBLs: high-energy peak, LBLs: low-energy peak, IBLs: intermediate). ... The observations were carried out with the RATAN-600 radio telescope during 2006-2011 at six frequencies: 1.1, 2.3, 4.8, 7.7, 11.2 and 21.7 GHz. ...

We present UV and optical spectropolarimetry of two highly polarized IRAS-selected quasi-stellar objects (QSOs), IRAS 13349+2438 and the broad absorption line QSO (BALQSO) IRAS 14026+4341. ... We construct full radiative transfer models of these systems consisting of a dusty sphere of modest optical depth illuminated axisymmetrically from within by a power-law QSO spectrum. We show that this simple model successfully reproduces the qualitative polarization properties of the objects. ...

... 6.09.1996 . ... Credit Copyright: The Clementine Project Explanation: What is the largest known impact crater in the Solar System? ... In general, the rocky terrestrial planets and moons are scarred and battered from frequent repeated bombardment by large objects during our Solar System's early years. ... Publications with keywords: impact crater . Publications with words: impact crater . ... 3D Barringer Meteorite Crater . ... Manicouagan Impact Crater on Earth . Barringer Crater on Earth . ...

In a recent study of z 0.1 active galactic nuclei (AGNs), we found that 21 cm absorption has never been detected in objects in which the ultraviolet luminosity exceeds L UV ~ 10 23 W/Hz. ... The fact that at L UV 10 23 W/Hz, both type-1 and type-2 objects exhibit a 50% probability of detection, suggests that this is not the case and that the bias against detection of H I absorption in type-1 objects is due purely to the inclusion of the L UV 10 23 W/Hz sources. ...

As a service to the astronomical community, we are recalibrating all archival Hubble Space Telescope Faint Object Spectrograph UV and optical spectrophotometry of active galaxies and quasars in order to extract uniformly calibrated spectrophotometric data for further detailed scientific investigations. ... NGC 4151 CLOUD F . NGC 5548 . ... NGC 4395 . ... NGC 4486 . ... NGC 4486 JET KNOT-A . ... NGC 4486 CLOUD-A . ... NGC 3031 . ... NGC 1068 . ... NGC 1068 CLOUD A . ... 1413+117A . ... NGC 4151 . ...

... The main topics of the Conference were: 1. ... Asteroid-comet hazard (origin and dynamic evolution of objects approaching the Earth, observations, physical properties, cataloguing, data bases, estimation of collision probability with the Earth and other bodies). ... 5) In this connection the problem of concluding the international political agreement within the frames of UN about common active counteractions to the bodies on the orbits leading to collisions with the Earth is urgent. ...

Nowadays at the Department the experimental and theoretical investigations, including astronomical and ionospheric observations, active experiments with space vehicles are taking place. ... Solar Corona physics and erruptive phenomenae. ... Stellar astronomy. ... The Department has organized and put into practice more then 50 expeditions for observation of Solar ecllipces, aurorae polaris, comets, meteor streams, controlled space experiments, and also for investigations of geophysical characteristics. ...

... 2003 July 5 . Centaurus A: X-Rays from an Active Galaxy . ... CXO , NASA . ... Astronomers were not disappointed, as Centaurus A's appearance in x-rays makes its classification as an active galaxy easy to appreciate. ... Blasting toward the upper left corner of the picture, the jet seems to arise from the galaxy's bright central x-ray source -- suspected of harboring a black hole with a million or so times the mass of the Sun. ... About APOD | ... NASA Official: Jay Norris. ...

... ESO, the European Southern Observatory . ... ESO's Governing Bodies . ... Travel to ESO Headquarters . ... Visits to ESO Sites . ... Architecture at ESO . Collaborations with ESO . ESO Acronyms . ... Galaxies . ... View shopping cart . ... Active Optics . ... This wide-field image shows the patch of sky around the distant active galaxy PKS 1830-211. This view was created from photographs forming part of the Digitized Sky Survey 2. ... ESO/Digitized Sky Survey 2. ... PKS 1830-211 . ...

... Tonight's Sky . ... The Magazine . ... Observing . ... Magazine . ... Product Reviews . ... View more active galactic nuclei . ... In the July 2013 article, Secrets of the brightest objects in the universe, I describe what astronomers currently know about quasars, which are the most luminous type of active galactic nuclei (AGNs). ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

An X-ray/radio sample of Active Galactic Nuclei Nuria Fonseca Bonilla Tutor: Stefano Bianchi Matteo Guainazzi An X-ray/radio sample of Active Galactic Nuclei Brief introduction Results Conclusions An X-ray/radio sample of Active Galactic Nuclei 1. ... Classification of AGN radio loud (powerful jets): e.g: radio galaxies, quasars, blazars... radio quiet radio quiet quasars (RQQs) Veron `06: MABS < -23 Seyfert Veron `06: MABS > -23 An X-ray/radio sample of Active Galactic Nuclei 3. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Solar System . ... Moon . ... Comets and Asteroids . ... What changed our view of Chariklo is the discovery of a ring system around it, the first such feature found around a Solar System body smaller than a gas giant planet. ... Almost certainly the rings were born when a collision with a smaller asteroid blasted millions of tonnes of debris off CharikloтАЩs surface. ... A ring system detected around the Centaur (10199) Chariklo (Braga-Rigas et al.) ...

... astro-ph . ... We present the goals and preliminary results of an unbiased, near-infrared, narrow-band imaging survey of the First Galactic Quadrant (10deg<l<65deg ; -1.3deg<b<+1.3deg). ... We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. ... Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes. ...

T he Siding Spring Survey (SSS) is a Near-Earth Object search program that utilises the 0.5-m Uppsala Schmidt Telescope at Siding Spring Observatory, N.S.W., Australia. ... The mission of the Siding Spring Survey is to contribute to the inventory of near-earth objects (NEOs), or more specifically, the potentially hazardous asteroids (PHAs) and comets (PHOs) that may pose a threat of impact and thus harm to civilization. ... Based on the CSS Mission page . ... Siding Spring Survey Main Page . ...

An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . ... a) Changes in the Solar System - Continued . The Cratered Face of the Moon Impact craters on the Earth, Moon, and other worlds are formed by the bombardment of chunks of rock and ice from space. ... So we conclude that the solar system experienced many more impacts in the distant past than today. ... The Changing Universe - Changes in the Solar System - Changes in Stars - Changes in the Universe | ...

... Kuiper belt objects are icy bodies in the outer solar system. ... Views of Kuiper Belt Objects . Object 1993 SC . This image shows a small part of the discovery frames of 1993 SC, one of the brightest Kuiper-Belt objects so far discovered. ... Assuming that Object 1993 SC reflects light much like other primitive asteroids and comets in the out solar system, the diameter is around 300 kilometers (186 miles), or just a quarter the size of Pluto's moon Charon. ... Comet Shoemaker-Levy 9 Impact . ...

. Cosmology . Very Early Universe . Cosmic Microwave Background Anisotropy . Dark Matter Models . Large Scale Structure . High Energy Astrophysics . Active Galactic Nuclei . Astrophysics of Compact Objects . Accretion Disks . Scientific Staff:

... For the past years I have been working on the problem of synthesis of light curves of close binary systems, consisting of a normal star and a compact object (point object with fixed X-ray luminosity). ... Possible existence of a bright spot on the disk's lateral surface is taken into account. ... The last of then will be published in Gordon and Breach Publishers ( Cherepashchuk A.M., Katysheva N.A., Khruzina T.S., Shugarov S.Yu. ... Cherepashchuk A.M., Katysheva N.A., Khruzina T.S., Shugarov S.Yu. ...