Stars with Exoplanets: V391 Pegasi (original) (raw)

V391 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