Gas-Giant Planet May Sport Cometlike Tail
A planet called HD 209458 b, aka Osiris, orbits its star so closely that it is losing some of its atmosphere to the stellar wind. It may thus have a cometary tail. Steve Mirsky reports
SUBSCRIBE TO Science Quickly
Whaddya get when you cross a planet with a comet? Well, HD 209458 b looks like a candidate. It’s a gas giant planet also called Osiris, and it’s orbiting so close to its star that some of its atmosphere gets blown away by the stellar wind. Astronomers think that it may then have a tail like a comet’s.
The researchers studied the odd object using the Hubble Space Telescope and reported their finding in the July 10th issue of The Astrophysical Journal. [Jeffrey Linsky et al., http://bit.ly/b77vzS]
The planet is about 153 light-years from Earth, and weighs a bit less than Jupiter. But its zippy orbit is a hundred times closer to its star than Jupiter’s is.
Astronomers got information about the planet by observing its effect on its star’s light when it moved in front of the star from our point of view. They found that most of the gas being driven away from the planet by its star was moving at 22,000 miles per hour. But don’t worry about the planet disappearing entirely any time soon. The current best estimate to complete the vaporization: a trillion years.
—Steve Mirsky
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
[The above text is an exact transcript of this podcast.]
It’s Time to Stand Up for Science
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.
In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.
