Next: A box, to include Up: To produce a region Previous: To produce a region . select cursor and circle . When in the image window, the mouse now has a box shape with an arrow at the upper left corner. The mouse buttons act as follows: . LEFT - to move the center of the circle at the position of the arrow point. ... RIGHT - idle. center the circle at the point source by positioning the arrow point and clicking on the LEFT mouse button. A circle will appear at the arrow position. ...

... Dark Energy (Part of the Hubble Discoveries Series): http://hubblesite.org/hubble_discoveries/dark_energy/ (Flash-based multimedia tutorial on the discovery and meaning of dark energy; includes information on the origin and fate of universe) . ... Cosmology Visualizations from the NASA Universe Forum: http://www.cfa.harvard.edu/seuforum/einstein/resources_visual.htm#featcos (A series of computer visualizations of the evolution and structure of the universe, available in a number of formats.) ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Equatorial coronal hole (top left), polar CH (top right), quiet Sun (bottom left) and quiet Sun with TCHs (bottom right) with the positions of all the corresponding identified brightening pixels over-plotted. ... We found that in comparison to the quiet Sun, the boundaries of coronal holes are abundant with brightening events including areas inside the coronal holes where closed magnetic field structures are present. ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Parkes radio telescope . ... This orientation-dependence has been incorporated into `unified schemes', which physically-link apparently disparate radio source types via the random orientation of a `parent' population on the plane of the sky. This paper summarises the `dual-population unified scheme' paradigm investigated by and discusses some of its implications with respect to radio source cosmology. ...

... The obtained results lead to the following conclusions: a) the heavy element enrichment had taken place in the Galaxy in a few bursts of its activity rether than in a continuons manner; b) these bursts occured during the callapse of the early Galaxy; c) the star formation had been inhibited in the time of the bursts; d) the metal enrichment did not proceed in the periods of star formation, between these bursts of activity. ...

... Articles | ... Forums . ... 230 deg . 49 deg . ... 130 deg . ... More Info . ... 210 deg . ... 168 deg . ... 249 deg . ... 195 deg . ... 271 deg . ... 110 deg . ... 338 deg . ... July 15 . 247 deg . ... 224 deg . ... 340 deg . ... July Phoenicids (PHE) . ... August 10 . 341 deg . ... 339 deg . ... 307 deg . ... 334 deg . ... 335 deg . ... 286 deg . ... 327 deg . ... 262 deg . ... 102 deg . ... 153 deg . ... 117 deg . ... December 2 . ... 123 deg . ... 100 deg . ... www.astronomy.net . ...

... 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. ...

... 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 . ...

... Triton: Neptunes Largest Moon . ... So, looking toward the Sun, extreme ultraviolet cameras onboard STEREO B were able to record a stunning movie of a lunar transit (aka solar eclipse), as the Moon tracked across the solar disk. ... Stars, Dust and Nebula in NGC 2170 . ... Visible above are red glowing emission nebulas of hydrogen, blue reflection nebulas of dust, dark absorption nebulas of dust, and the stars that formed from them. ... APOD: 2007 February 24- X rays and the Eagle Nebula . ...

... a) As source material for the high-school or college curriculum, especially in physics. astronomy and their history. (b) As a source of supplemental projects by high school students or by undergraduates. (c) As material for independent studies, In particular by motivated students who seek to know more about space . ... Those wishing to look up specific topics are advised to use the index file, accessible from the end of any "Exploration" file. ... files not listed and at other resource material. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...