... 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 . ...

... Archives . ... my first AAS. ... I was questioned by two attendees, acquainted before the AAS, if I can suggest them clustering methods relevant to their projects. ... classification vs. clustering or supervised learning vs. unsupervised learning : the former terms from the pairs indicate the fact that the scientist already knows types of objects in his hands. ... Tags: Classification , clustering , cosmology , spatial statistics , supervised learning , test , unsupervised learning . ...

Target names are used to provide unique designations for the targets that will be used throughout the proposal. These names will generally also be used in Phase II, and ultimately to designate targets in the HST data archive. ... This facility will be most useful if consistent naming conventions are used. ... If a target is not contained in these catalogs, other catalog designations may be used (e.g., 4U X-ray catalog designation, Villanova white-dwarf catalog number, etc.) ... Target Type . ...

... Structure of Data . ... Catalog . ... In SAI OCL Catalog, we introduce our work on investigation of the Milky Way system of open star clusters. The main goal of our study is a search for new clusters using huge surveys. 168 new clusters have been already discovered by us using J,H,Ks data from 2MASS point source catalog. ... For 141 new clusters, we found their physical parameters using J,H,Ks data from 2MASS catalog and, for a number of clusters, our UBVRI CCD observational magnitudes. ...

... The routines implemented are CLUSTER which has 8 options for hierarchical clustering and PARTITION which carries out non--hierarchical clustering. ... The former is non--hierarchical clustering or partitioning. The latter is hierarchical clustering. Brief consideration will show that a sequence of n-1 agglomerations are needed to successively merge the two closest objects and/or clusters at each stage, so that we have a set of n (singleton) clusters, n-1 clusters, ..., 2 clusters, 1 cluster. ...

... Next: Unsupervised Catalog Classification Up: Object Detection and Previous: Classification of Objects . ... Multi-resolution allows for image analysis in terms of different scales. ... This approach is used for the detection (and subsequent analysis) of globular cluster systems around elliptical galaxies, and for image characterization and object trawling in large image databases. ... The applicability of this approach to object detection in large image collections has been investigated. ...

... Editor's choices for the most educational Astronomy Pictures of the Day about clusters of galaxies: . APOD: 2006 March 21 - The Coma Cluster of Galaxies . ... APOD: 2005 November 22 - A Galactic Collision in Cluster Abell 1185 . ... A prominent example occurs on the left of the above image of the rich cluster of galaxies Abell 1185. ... Recent observations of Abell 1185 have found unusual globular clusters of stars that appear to belong only to the galaxy cluster and not to any individual galaxy. ...

... Observations . Objects . ... Canis Major . ... Canis Minor . ... Leo . ... Leo Minor . ... Ursa Major . ... Ursa Minor . ... Herschel 2500 . ... Herschel 400 (I) . ... Globular Clusters . ... AL Globular Club . ... AL Planetary Club . ...

... 2003, ApJL, in press . ... 2003, A , in press . HST/STIS observations of rotation of T Tauri jets . ... 2003, Proceedings of "JENAM 2002: The early stages if star formation", in press . ... 2003, ApJ, in press . ... S. Hotzel, J. Harju, C.M. Walmsley . ... E. Habart, A. Abergel, C.M. Walmsley, D. Teyssier . ... Codella, C., Bachiller R., Benedettini M., Caselli P. MNRAS, 2003, in press . ... Bianchi S., Goncalves J., Albrecht M., Caselli P., Chini R., Galli D., Walmsley M. 2003, A 399, L43 . ...

... M15: A Great Globular Cluster . ... Credit: The Electronic Universe Project Explanation: A globular cluster is a system of about one million stars that together orbit a galaxy. One of the brightest globular clusters in our Milky Way galaxy is the pictured M15, the fifteenth object on Messier's list of diffuse objects on our sky. ... Publications with keywords: M15 - globular cluster . Publications with words: M15 - globular cluster . ... M13: The Great Globular Cluster in Hercules . ...

Proposal Identi cation No.: P1134 Date Received: 1998-Feb- 1 19:19:37 Technical Page Proposal Type: Regular General Category: Pulsars Observation Category: Total Time Requested: 67 Hours Proposal Title: A Search for Giant Pulses from M33 and Nearby Globular Clusters ABSTRACT: We propose a search for `giant' pulses from Crab-like objects (in the spiral galaxy M33) and fast pulsars (in globular clusters) too weak to be detected by their average uxes. ... Maybe Part of the observing run. ...

... Indeed, one alteration of orbits can be the outright ejection of a planet. When several big planets are orbiting a star under each other's influence, the system is inherently unstable. ... We know of no good reason why the smallest objects with fusion should have the same mass as the smallest objects that can form by themselves. ... 6) Mission Definition . ... I don't think this mission is impossible, and will suggest a definition in a future article in Mercury. ... Good luck! . ...

IFP gallery SCORPIO (since 2000). Here some data observed on the 6m telescope with IFP installed in the SCORPIO focal reducer are presented. ... Velocity field . Mkn 1157 was observed 1 Sep. 2002 in the Ha emission line. Texp =32x240 sec, seeing 1.5", IFP260. ... This galaxy was observed September, 23 2000 in the Ha emission line, Texp=32x120 sec, seeing 2.5", IFP260. ... PV Cep was observed at the 6m telescope in May, 25 2003 in the [SII] 6716A with IFP501, Texp=36x200 sec, seeing 1.0". ...

... Tonight's Sky . ... Observing . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... The 109 objects in a March globular cluster marathon . ... In the March 2014 issue of Astronomy, I challenged readers with the question, How many globular clusters can you see in might night? Taking the Messier marathon as inspiration, I made a list of 109 globular clusters to track down in a single night in March. ... Get instant access to subscriber content on Astronomy.com! ...

... Science . ... Science Users Information > Science Activities > VLT/VLTI Science Verification > VIMOS . ... Observing with ESO Telescopes . ... Data Handling and Products . ... Science Data Products Forum . ... ESO Data . ... ESO Data Access Policy . ... VLT/VLTI Science Verification . ... VISTA Science Verification . APEX Science Verification . ... ESO Science Newsletter . ... A VIMOS-IFU Study of Early-Type Galaxies . ... NGC 1427 (03h42m19.4s -35d23m34s) . ... Program to be observed . ...

ATMoB "Open Cluster Observing Award " Guidelines Purpose: To promote observing among the membership of the Amateur Telescope Makers of Boston through participation in the Open Clusters Observing Awards program. Introduction: This awards program is oriented towards visually observing open clusters above magnitude 9.9. ... It turns out that a very unprejudiced and convenient method to dermine the limiting magnitude is to count the number of visible stars in certain areas on the sky. ...

... Contacts . 2012: . ... We refined the fundamental parameters of the components, the orbital periods, and the conditions of photospheric heating of the secondary component by the ultraviolet radiation of the hot component. ... The observations of the star clusters associated with ultra-luminous x-ray sources (ULXs) in four galaxies on the 6-meter and VLT telescopes have shown that all the ULXs are located within 200pc of very young star clusters (younger than 5 million years). ... Archive . ...

... Courtesy of NASA/ESA Observation data (J2000 epoch) Constellation Right ascension Declination Redshift Distance Type Serpens Caput 15h 17m 14.4s[] +21° 35 08[] 12,740±50 km/s[][1] 600±30 Mly (183±8 Mpc)[1] SA0(r) [citation needed ] [a] Apparent dimensions (V) 0.28 в 0.28[] Apparent magnitude (V) 16.0[] Notable features Ring galaxy Other designations PGC 54559,[] PRC D-51[] See also: Galaxy, List of galaxies Hoag's Object is a non-typical galaxy of the type known as a ring galaxy. ...

... Australia Telescope Compact Array . ... Compact Stellar Systems in the Fornax Cluster: Super-massive Star Clusters or Extremely Compact Dwarf Galaxies? ... We suggest that these objects are either super-massive star clusters (intra-cluster globular clusters or tidally stripped nuclei of dwarf galaxies) or a new type of low-luminosity compact elliptical dwarf (``M32-type'') galaxy. ... Keywords: galaxies: star clusters -- galaxies: dwarf -- galaxies: formation . ... Properties of the compact objects ...