Enormous planet quickly orbiting a tiny, dying star

A few days old, but amazing...

Thanks to a bevy of telescopes in space and on Earth -- and even a pair of amateur astronomers in Arizona -- a University of Wisconsin-Madison astronomer and his colleagues have discovered a Jupiter-sized planet orbiting at breakneck speed around a distant white dwarf star.

The system, about 80 light years away, violates all common conventions about stars and planets. The white dwarf is the remnant of a sun-like star, greatly shrunken down to roughly the size of Earth, yet it retains half the sun's mass. The massive planet looms over its tiny star, which it circles every 34 hours thanks to an incredibly close orbit. In contrast, Mercury takes a comparatively lethargic 90 days to orbit the sun. While there have been hints of large planets orbiting close to white dwarfs in the past, the new findings are the clearest evidence yet that these bizarre pairings exist. That confirmation highlights the diverse ways stellar systems can evolve and may give a glimpse at our own solar system's fate. Such a white dwarf system could even provide a rare habitable arrangement for life to arise in the light of a dying star.

"We've never seen evidence before of a planet coming in so close to a white dwarf and surviving. It's a pleasant surprise," says lead researcher Andrew Vanderburg, who recently joined the UW-Madison astronomy department as an assistant professor. Vanderburg completed the work while an independent NASA Sagan Fellow at the University of Texas at Austin.

ScienceDaily