December 2, 2003
(PLANETQUEST) -- The fifth-brightest star in the night sky may be home to planetary system similar to ours, according to new research by astronomers at the Royal Observatory in Edinburgh. Computer modeling techniques have shown that the structure of a faint dust disk around Vega can be best explained by a Neptune-like planet orbiting at a similar distance to Neptune in our own solar system and having similar mass.
The wide orbit of the planet, most likely a gas giant, allows plenty of room inside it for small, rocky planets similar to the Earth -- the kind that could potentially support life. Although astronomers have already detected more than 100 planets around stars other than the Sun, none are of the type believed to be capable of sustaining life as we know it.
The modeling of the Vega system, described this week in The Astrophysical Journal, is based on observations taken with the world's most sensitive submillimeter camera, called SCUBA. The camera is operated on the James Clerk Maxwell Telescope in Hawaii. The SCUBA image shows a disk of very cold dust (-180 degrees centigrade) in orbit around the star.
The irregular shape of the disc suggests that it contains planets, according to astronomer Mark Wyatt, the author of the paper. Although we can't directly observe the planets, they have created clumps in the disk of dust around the star.
The star Vega is located 25 light-years from Earth and forms part of the constellation Lyra (the Harp). Together with Deneb and Altair, it forms the summer triangle, and is the brightest star in the summer sky over North America.
Previous research by the Harvard-Smithsonian Center for Astrophysics has also suggested the presence of unseen planets around Vega.
