International Meteor Organization | International Collaboration in Meteor Science. The Very Large Telescope. <div class="box3"><b>Did you know? </b> The smallest detail distinguishable with the VLT's adaptive optics system is smaller than the size of a DVD on the International Space Station, as seen from the ground (about 50 milliarcseconds). </div> Did you know? The smallest detail distinguishable with the VLT's adaptive optics system is smaller than the size of a DVD on the International Space Station, as seen from the ground (about 50 milliarcseconds).
Did you know? Did you know? Did you know? Did you know? Did you know? Did you know? Did you know? Did you know? Science::.. The Astrophysical Journal. Impossible supernova confounds astronomers. Researchers in Canada have detected a highly unusual Type Ia supernova (SNLS-03D3bb) that is just over twice the usual brightness for such an event. The finding could cause experts to re-evaluate a fundamental measure that underpins our understanding of the universe’s expansion (Nature 443 308). Type Ia supernovae occur when the mass of a white dwarf approaches the Chandrasekhar limit of 1.4 solar masses -- usually by the accretion of matter from a nearby star.
These explosions usually have the same brightness and, as a result, serve as ‘standard candles’ for measuring distances in the Universe. “We've found a supernova that is so bright that it ought to have been impossible,” University of Toronto astronomer Andy Howell, lead author of the study, told physicsweb.org. “Now we have to take a hard look at our theoretical understanding of Type Ia Supernovae and figure out how this could have happened.”
Hypervelocity star. A star that is ejected at very high velocity (on the order of 1,000 km/s) from the center of a galaxy due to interaction with a massive central black hole. The existence of hypervelocity stars was first proposed in 1988. Computer models indicated that hypervelocity stars ought to be a natural consequence of binary stars coming close to the supermassive black hole known to exist at the heart of our own Milky Way Galaxy. When a binary swings too close to the central black hole, the intense gravity can tear the binary apart, capturing one star while violently flinging the other outward at enormous speed. In 2005, the first hypervelocity star was discovered by astronomers using the Multiple Mirror Telescope in Arizona. Known as SDSS J090745.0+024507, it is 71 kiloparsecs from the Sun and moving through the outskirts of the galaxy – the so-called galactic halo – at about 850 km/s (528 miles/sec).
Archived news First stellar outcast discovered by astronomers (Feb 9, 2005) Related entry.