Orphan planet wanders 'near' Earth
There's an orphan planet roaming our galactic neighborhood.
It's a globe of gas about the size of Jupiter, astronomers say. And it's out there by its lonesome, untethered to any star, drifting about 100 light-years from Earth. (In astronomical terms, that's close.) Astronomers have spied lonely planets before. But this newest object, spotted near the southern constellation Dorado, is the closest to Earth yet found.
Unobscured by starlight, the new planet — it has no name, just a catalog number — provides a perfect opportunity for astronomers to learn about the mysterious class of “substellar objects.” Such rogue bodies might number in the billions in our galaxy alone.
“There could really be a lot of them,” said Christian Veillet, former director of the Canada-France-Hawaii Telescope, who studied the lonely planet. “But it's a big challenge in terms of observing them.”
That's because these drifting bodies are dark. With no home star, they reflect no starlight, nor do they generate any. But, like an iron pulled from a fire, the youngest of these objects still glow with the heat of their creation.
In 2009, astronomers in Hawaii spied such a heat signal with an infrared camera. A team at the Paranal Observatory in Chile then swung a big telescope around to take a peek.
They detected a planetlike object, estimated to be as big around as Jupiter but perhaps four to seven times as huge. Instruments sensed ammonia, methane and water vapor in the object's atmosphere — typical of Saturn, Jupiter, Neptune and Uranus, the gas-giant planets in our own solar system.
By watching the object's motion, astronomer Jonathan Gagne of the University of Montreal concluded that the planet is probably part of the AB Doradus group, a loose collection of 30 stars that formed from the same cloud of galactic gas. That cloud must have broken off a small puff that coalesced into the lonely planet, Gagne and his colleagues surmise.
Connecting the planet to the star group was key to determining that it is young, just 50 million to 120 million years old, Gagne said. (Our solar system, in contrast, is 4.5 billion years old.) Its youth, in turn, was crucial for classifying the object as a planetlike body rather than a brown dwarf, an object almost large enough to ignite and become a star. To be a brown dwarf, the object would have to be much older, Veillet said.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.
- Steelers QB Roethlisberger not targeting Oct. 25 return
- Rossi: Time for Pirates to take next step
- Trump falls to Democrats in latest poll of swing states
- Steelers notebook: Tomlin not worried about Jones’ lack of sacks
- Penguins rally in wake of Dupuis injury
- New Florence assistant fire chief charged with having sex with juvenile
- Wolf still seeking to raise income tax, impose tax on shale-gas drilling
- Fleury’s demeanor helps keep Penguins loose, him playing his best
- Same cast, improved results for Pitt defense
- Gorman: A ridiculous rule for golf
- Penguins make moves in advance of roster deadline