V391 PegasiV391 Pegasi probably is a pulsating subdwarf, a kind of white dwarf, which after its red giant-stadium casted away its hull not only mostly, but completely. Every 3.2 years it is orbited by a gas planet with 3.5 times Jupiter's mass in a distance of 1.7 AU.So this planet, Pegasi V391 b, one of the oldest known to us, has spent a long time next to a red giant, without being destroyed. The red giant may nearly have reached the orbit of the planet in its largest phase. Constellation: Pegasus Age: > 10 billion years Distance: 4500 light-years Spectral class: sdB Visual magnitude: 14.57 Mass: 0.5 * Sun Back: List of Exoplanets 09/14/2007 |
V391 Pegasi about 100 million years ago: a planet orbits a red giant. Graphic: Mark Garlick, Image courtesy of HELAS |
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