Skip to main content

binarysystem
Artist's conception of the newly discovery planet orbiting two stars. (T. Pyle/NASA)
The European Southern Observatory dazzled the world on Monday with news it had discovered only the second, and smallest ever, planet orbiting within the habitable zone of a star other than our own.

Now it's NASA's turn to amaze us with a new exoplanet find.

The Kepler Mission, run out of the Ames Research Center, today announced the first discovery of a planet orbiting a binary star system. As many news outlets have noted, and as NASA itself promoted when announcing the discovery, the find is reminiscent of Luke Skywalker's home planet of Tatooine in Star Wars:

Like the imaginary Star Wars world Tatooine, a new planet found 200 light-years away has two suns, astronomers announced today.

NASA's Kepler spacecraft uncovered the new planet, dubbed Kepler 16b, as it transited—or crossed in front of—both its parent stars, causing the brightness of each star to dim periodically.

In addition to not being in a galaxy far, far away, there are some differences between Tatooine and Kepler 16b. In particular, Kepler 16b is cold and gaseous, rather than a habitable, rocky desert. Still, it is a remarkable find which greatly expands the potential number of habitable worlds:

"This discovery confirms a new class of planetary systems that could harbor life," Kepler principal investigator William Borucki said. "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now."

Today's announcement is the latest in a growing string of amazing findings by the Kepler mission:

On 2 February 2011, the Kepler team announced the results from the data of May to September 2009. They found 1235 planetary candidates circling 997 host stars, more than twice the number of currently known exoplanets. The Kepler results included 68 planetary candidates of Earth-like size and 54 planetary candidates in the habitable zone of their star. The team estimated that 5.4% of stars host Earth-size planet candidates and 17% of all stars have multiple planets. As the mission continues, additional longer period candidates continue to be found - as of September 2011, there were 1781 candidates

Kepler is able to make so many exoplanet findings because it is a space-based observatory employing the transit method of exoplanet detection. By continually monitoring the brightness of 150,000 stars, Kepler finds exoplanets when they cross in front of their host star, thus reducing the brightness of those stars.

In contrast, the HARPS team at the European Southern Observatory uses the radial velocity method of exoplanet detection. By measuring how much a star moves, it is possible to determine if, and how much, gravity is being exerted on the star by orbiting planets.

The benefit of the transit system utilized by Kepler is that it can detect the presence of far more exoplanets, since it can monitor so many stars at once. The benefit of the radial velocity method is that it can detect exoplanets other than those which cross between their host star and an observer's line of sight (which are 99.8 percent of all exoplanets).

Both methods are indispensible, and are producing multiple breakthroughs every year. We should consider ourselves lucky if the two methods continue one upping each other, just as they have done this week.

Originally posted to Chris Bowers on Thu Sep 15, 2011 at 03:00 PM PDT.

Also republished by Astro Kos and Daily Kos.

EMAIL TO A FRIEND X
Your Email has been sent.
You must add at least one tag to this diary before publishing it.

Add keywords that describe this diary. Separate multiple keywords with commas.
Tagging tips - Search For Tags - Browse For Tags

?

More Tagging tips:

A tag is a way to search for this diary. If someone is searching for "Barack Obama," is this a diary they'd be trying to find?

Use a person's full name, without any title. Senator Obama may become President Obama, and Michelle Obama might run for office.

If your diary covers an election or elected official, use election tags, which are generally the state abbreviation followed by the office. CA-01 is the first district House seat. CA-Sen covers both senate races. NY-GOV covers the New York governor's race.

Tags do not compound: that is, "education reform" is a completely different tag from "education". A tag like "reform" alone is probably not meaningful.

Consider if one or more of these tags fits your diary: Civil Rights, Community, Congress, Culture, Economy, Education, Elections, Energy, Environment, Health Care, International, Labor, Law, Media, Meta, National Security, Science, Transportation, or White House. If your diary is specific to a state, consider adding the state (California, Texas, etc). Keep in mind, though, that there are many wonderful and important diaries that don't fit in any of these tags. Don't worry if yours doesn't.

You can add a private note to this diary when hotlisting it:
Are you sure you want to remove this diary from your hotlist?
Are you sure you want to remove your recommendation? You can only recommend a diary once, so you will not be able to re-recommend it afterwards.
Rescue this diary, and add a note:
Are you sure you want to remove this diary from Rescue?
Choose where to republish this diary. The diary will be added to the queue for that group. Publish it from the queue to make it appear.

You must be a member of a group to use this feature.

Add a quick update to your diary without changing the diary itself:
Are you sure you want to remove this diary?
(The diary will be removed from the site and returned to your drafts for further editing.)
(The diary will be removed.)
Are you sure you want to save these changes to the published diary?

Comment Preferences

Subscribe or Donate to support Daily Kos.

Click here for the mobile view of the site