Stories
Slash Boxes
Comments

SoylentNews is people

posted by martyb on Friday December 04 2015, @12:36AM   Printer-friendly
from the still-leaves-a-lot-of-exoplanets dept.

Over half of the gas giant "exoplanets" spotted by the Kepler telescope may actually be explained by other astrophysical phenomena, such as binary stars and brown dwarf stars:

It's always exciting when Kepler discovers a new exoplanet, and it's generally assumed that there is a relatively low chance of a false positive. But according to a new study, there may be a much higher rate of false positives than we thought with regard to gas giants, possibly up to 55%.

In the study, astronomers from Instituto de Astrofísica e Ciências do Espaço examined a sample of 129 gas planets detected by Kepler through the transit method. The transit method involves extrapolating the existence of a planet from the periodic dimming of a star's light emission that is presumably caused by an exoplanet's orbit. They found that approximately half of them weren't planets at all; rather, the light's dimming was caused by some other astrophysical phenomenon.

Gas giants are particularly vulnerable to false positives, as they can easily be imitated by eclipsing binaries. Eclipsing binaries are binary star systems aligned with the observer's (in this case, Kepler's) line of sight, which causes the larger star to block the light from the smaller. The researchers found that 52.3% of the gas giants were actually eclipsing binaries, while 2.3% were brown dwarfs, or a "failed star" between gas giants that doesn't have enough mass to fuse hydrogen to its core.

Also at the Institute of Astrophysics and Space Sciences.

SOPHIE velocimetry of Kepler transit candidates XVII. The physical properties of giant exoplanets within 400 days of period


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 0) by Anonymous Coward on Friday December 04 2015, @09:13AM

    by Anonymous Coward on Friday December 04 2015, @09:13AM (#271741)

    The alleged false positives are for gas giants, which wouldn't be supportive of life anyway. As far as I can see, they don't claim false positives on the smaller rocky planets, which are the ones which possibly bear life.

  • (Score: 2) by PiMuNu on Friday December 04 2015, @09:29AM

    by PiMuNu (3823) Subscriber Badge on Friday December 04 2015, @09:29AM (#271743)

    Except for moons:

    http://geology.com/stories/13/life-on-europa/ [geology.com]

  • (Score: 2) by cubancigar11 on Friday December 04 2015, @02:38PM

    by cubancigar11 (330) on Friday December 04 2015, @02:38PM (#271793) Homepage Journal

    The percentage of rocky/inhabitable planets among all the planets found so far does change with this news.