... May 22, 1996 . Star Cluster in the Rosette Nebula . ... Explanation: Embedded in the center of the colorful and photogenic Rosette Nebula is a bright, young open cluster . The bright blue stars in this cluster, labelled NGC 2244, emit ultraviolet light that knocks electrons away from hydrogen atoms . ... The Rosette Nebula is thousands of light years distant, but light would take only about 100 years to cross it. ... Tomorrow's picture: The Violent Star Cluster 30 Doradus . ... About APOD | ...

... 2011 July 15 . NGC 3314: When Galaxies Overlap . Credit: Hubble Legacy Archive , ESA , NASA ; Processing - Martin Pugh . Explanation: NGC 3314 is actually two large spiral galaxies which just happen to almost exactly line up. ... NGC 3314 is about 140 million light-years (background galaxy) and 117 million light-years (foreground galaxy) away in the multi-headed constellation Hydra . The background galaxy would span nearly 70,000 light-years at its estimated distance. ... About APOD | ...

Astronomy Picture of the Day . Star Cluster in the Rosette Nebula . ... 22.05.1996 . ... The bright blue stars in this cluster, labelled NGC 2244, emit ultraviolet light that knocks electrons away from hydrogen atoms. ... The Rosette Nebula is thousands of light years distant, but light would take only about 100 years to cross it. ... Publications with keywords: star cluster - Rosette Nebula . Publications with words: star cluster - Rosette Nebula . ... Hot Stars in the Rosette Nebula . ...

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 . ...

... Tonight's Sky . ... Sky this Month . ... Star Atlas . ... stars . ... The Sky This Week: April 1 - 10 . ... Observing springtime deep-sky objects with a large telescope . ... Why do some stars appear to flash a variety of different colors when you look at them through a telescope? ... So, Earthт??s atmosphere will bend some colors from especially bright stars more so than others, which makes the source look like itт??s flashing colors. Get instant access to subscriber content on Astronomy.com! ...

... 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. ...

... self-absorption - the absorption of light shining on an object by a process similar to that which produced the light originally; if a cloud emits less light than it absorbs from other clouds behind it, this net loss of light, termed self-absorption , causes the foreground cloud to appear darker than the background field (the term is from spectroscopy, where small absorption dips sometimes occur in larger emission lines, making the latter look as if it is absorbing part of itself) . ... HISA Main ...

EMBARGOED UNTIL: 9:20 AM CST, January 6, 1999 CONTACT: John Biretta Space Telecsope Science Institute, Baltimore, MD (Phone: (410) 338-4917; Internet: biretta@stsci.edu) HUBBLE DETECTS FASTER-THAN-LIGHT MOTION IN GALAXY M87 Astronomers reported today discovering clouds which appear to move many times faster than the speed of light, shooting out from the region of a black hole at the center of the M87 galaxy. ... It's an illusion created by the finite speed of light and rapid motion," Biretta said. ...

In autumn 1994, two groups of astronomers announced that they had discovered Cepheid variable stars in a distant cluster of galaxies. ... As the term suggests, variable stars change in brightness over time. ... Variable stars are an ideal way to get high-school students doing real science, with real data, from the real sky. ... a sky chart to find the stars . ... Students can use the nearby stars to estimate the magnitude of Delta. ... Locate the star Delta in Cepheus and estimate its brightness . ...

... See Environment File. ... An SM expression is something that can appear on the right hand side of a SET command. ... A filecap file is a database used to describe the byte-by-byte format of binary files, to allow SM to read them (using the IMAGE command). ... The word list is used in a few places in the manual in the specific sense defined by the YACC grammar in `control.y' . ... Their peculiarities are described by a termcap file, allowing SM's command editor to run on (almost) any terminal. ...

A team of U.S. and German astrophysicists have made the first ever detection of X-rays coming from a comet. ... Following the initial detection, the team reported repeated X-ray emissions from the comet over the next 24 hours. ... One preliminary theory is that X-ray emission from the Sun was absorbed by a cloud of gaseous water molecules surrounding the nucleus of the comet, and then were re-emitted by the molecules in a process physicists call "fluorescence." ... Comets . ...