Circling a Black Hole at its Photon Sphere . ... One particularly interesting place near a black hole is its photon sphere, where photons can orbit in circles, a sphere 50 percent further out than the event horizon. Were you to look out from the photon sphere of a black hole , half of the sky would appear completely black, half of the sky would appear unusually bright, and the back of your head would appear across the middle. ... Disclosure: Video creator Robert Nemiroff is an editor for APOD.) ...

... 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. ...

... 2013 July 2 . Circling a Black Hole at its Photon Sphere . ... One particularly interesting place near a black hole is its photon sphere , where photons can orbit in circles, a sphere 50 percent further out than the event horizon . Were you to look out from the photon sphere of a black hole , half of the sky would appear completely black, half of the sky would appear unusually bright, and the back of your head would appear across the middle. ... About APOD | ...

... The TRACE images may be used without restrictions in publications of any kind. ... These two images, taken on 18 November 2000 at 15:54UT and 16:11UT, respectively, show such an event: the red circle in the image to the left shows a region where many loops are cooling, with bright loop tops (the intensity scales with the square root of the image to reduce the dynamic range). ... See also a collection of images related to the Sun, other cool stars, and solar-terrestrial effects . ... Images | ...

... SEARCH ASP SITE: Match ALL words Match ANY word . ... ASP Conference Series . ... Accidental Astrophysics: The Devil's In the Magnitudes, Part II . ... The star second to the Sun in brilliance is Sirius. ... Recall the magnitude system, passed down to us through a hundred generations of sky watchers, as a means of quantifying stellar brightness ("Accidental Astrophysics," May/June, p. 9). ... Yes, it is a magnitude difference, but that difference is due to the distance between us and the star. ...

... Circumstellar disc of beta Pictoris: constraints on grain properties from polarization. To appear in the Astronomy & Astrophysics . abs , src , ps ] . ... Dust influx to Titan from Hyperion . ... abs ] . ... Characteristics of bulges and disks in interacting galaxies . ... Dust grains around Herbig Ae/Be stars: porous, cometary-like grains? ... To appear in the Astronomy & Astrophysics Supplement . ... Finally, Links may lead you to more options (e.g. via the LANL preprint system). ...

... The blue bubble is a planetary nebula known as Abell 33. Planetary nebulae are created when an aging star blows away its outer layers of gas in a gigantic cosmic bubble. ... Creating the illusion of the cosmic diamond is a bright star along the rim of the nebula. ... The star is about 700 light years away, that is halfway between Earth and the nebula. ... At the centre of the ring, you can see the remains of the star that created this planetary nebula, now a white dwarf . ...

This month's Geminid meteor shower is expected to peak around the late evening of Tuesday 13th/early hours of Wednesday 14th. The shower is usually one of the best of the annual meteor showers, with many relatively bright, slow- to medium-speed fireballs. ... These meteors are believed to originate from the near-Earth asteroid, Phaethon, discovered by a NASA satellite in 1983. ... FOR FURTHER INFORMATION CONTACT: John McFarland at the Armagh Observatory, College Hill, Armagh, BT61 9DG. ...

Astronomy Discussion Forums . ... Atm ћ Astrophotography ћ Blackholes ћ Blackholes2 ћ CCD ћ Celestron ћ Domes ћ Education . ... New Model: How Do The Sun And Moon Appear To Move Across The Sky . ... Post Message | ... focused on the Sun and the Moon as they appear from the given location of the Earth surface: . ... www.astronomy.net . About Astronomy Net | ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... 2004: . ... An increase in star brightness is followed by a decrease in asphericity and wind velocity to the point where stationary and even accreting fraction of the wind appears in extremely bright objects together with a flowing out fraction. ... Based on an analysis of observations obtained with BTA and on the published data it was found that degree of abnormality of energy distribution in continuum of magnetic chemically peculiar stars increases with an increase of their rotation period. ...