Observation Checklist . Instructions for remote observing with Arecibo . ... Enter an Observation Log . View the current Observation Log . View the Observation Log for the January 2006 run . View the Observation Log for the May 2006 run . View the Observation Log for the July/August 2006 run . View the Observation Log for the December 2006 run . View the Observation Log for the January/February 2007 run . View the Observation Log for the April 2007 run . ...

... Our Sun is part of a huge wheel-shaped collection of stars. ... Astronomers have long suspected it was a very massive black hole, and that every galaxy had such a central mass, created early in the history of the universe. ... However, unless that object happens to be headed directly at the black hole (a relatively small target) it will just swing around and fly away again, like a comet making a pass at the Sun. The velocity acquired in falling towards the black hole also helps it escape. ...

... We suggest simple method of the selection of distant galaxies based on their radio properties. ... RC0015+0503a , RC0015+0503b , RC0015+0501 , RC0034+0513 , RC0038+0449 , RC0042+0504 . ... RC0105+0501 , RC0110+0500 , RC0117+0503 , RC0126+0502 , RC0133+0459 , RC0135+0450 , RC0137+0539 , RC0143+0505 , RC0152+0453 , RC0154+0459 , RC0159+0448 . ... RC0209+0501b , RC0213+0516 , RC0226+0512 , RC0250+0512 . ... RC0302+0456 , RC0308+0454 , RC0311+0507 , RC0318+0456 , RC0355+0449 . ...

... The search for distant objects which can be both galaxies and quasars is one of the most important problems of observational astrphysics, because it allows one to determine cosmological parameters connected with the time of appearence and evolution of stellar systems, large scale structure of the Universe. ... Radio galaxies are important objects to be studied because they are sources of infrared-optical-ultraviolet continuum, emission lines and continual radio emission. ...

... 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. ...

... Visible Distribution of Galaxies. ... Features of Elliptical, Lens-Shaped, Spiral and Irregular Galaxies. Galaxies with Bar. ... Distribution of Surface Brightness of Surface and Spiral Galaxies. ... Color Characteristics of Galaxies. ... Methods of Galaxies' Mass Determination. ... Hidden Mass of Spiral Galaxies. ... Features of Dark Matter Distribution in E and SO Galaxies. ... The Whole Number of Galaxies and Their Density by the Results of Observation on the 'Hubble' Space Telescope. ...

... 2015 - 2016 . ... Eugene Higgins Professor of Astrophysics, Princeton University . ... December 8, 2015 . ... November 10, 2015 . ... University of the Sciences in Philadelphia author . ... Amateur Astronomer . ... 2014 - 2015 . ... June 9, 2015 . ... Digital Planetarium and the 2012 Transit of Venus from Hawaii . 2013 - 2014 . ... International Occultation Timing Association . ... 2012 - 2013 . ... 2011 - 2012 . ... Princeton University . ... Amateur Astronomers Association of Princeton, Inc., ...

... Bad Astronomy . ... Mad Science . ... Site Info . ... Public Talks . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... Who is this guy who calls himself "The Bad Astronomer?" ... First, yes, I am a real live astronomer (when people ask me what astronomers do, I tell them "They astronom !" ... These are emitted by powerful objects like black holes, exploding stars, and super-dense neutrons stars. ... Finally, am I really a bad astronomer? ... 2008 Phil Plait. ...

Abstract -- Abundances of heavy elements decreases with increasing galactocentric distance almost in all disk galaxies. ... To explain this gradient in young objects and in the interstellar gas one has to assume that a typical disk galaxy is an open system, i.e. it expels some synthesized heavy elements into the circumgalactic space and/or accretes intergalactic gas with zero metallicity, with rates of both processes depending on the galactocentric distance. ...