More than half Kepler planet candidates false positives
The uncertainty of science: In attempting to confirm the giant exoplanet candidates in the Kepler telescope database a team of scientists has found that more than half are not planets at all but false positives.
An international team1 led by Alexandre Santerne from Instituto de Astrofísica e Ciências do Espaço (IA), made a 5-year radial velocity campaign of Kepler’s giant exoplanet candidates, using the SOPHIE spectrograph (Observatory of Haute-Provence, France), and found that 52,3% were actually eclipsing binaries, while 2,3% were brown dwarfs. Santerne (IA & University of Porto), first author of this paper commented: “It was thought that the reliability of the Kepler exoplanets detection was very good – between 10 and 20% of them were not planets. Our extensive spectroscopic survey, of the largest exoplanets discovered by Kepler, shows that this percentage is much higher, even above 50%.
The news article above is unclear about the number of candidates total this study actually looked at and pinned down. It appears they began looking at the full database of almost 9,000 candidates, but then narrowed it to 125. Were 50% of the 9,000 false positives, or of the 125? The article is unclear.
At first glance, this study appears to tell us that there might be fewer giant Jupiter-sized exoplanets out there than previously thought. Then again, the data is uncertain enough that this conclusion could easily be wrong. The real take-away is that the science of exoplanets has only just begun, and that sweeping generalizations about the nature of solar systems in the galaxy are exceedingly unreliable. We simply don’t know enough yet.
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The uncertainty of science: In attempting to confirm the giant exoplanet candidates in the Kepler telescope database a team of scientists has found that more than half are not planets at all but false positives.
An international team1 led by Alexandre Santerne from Instituto de Astrofísica e Ciências do Espaço (IA), made a 5-year radial velocity campaign of Kepler’s giant exoplanet candidates, using the SOPHIE spectrograph (Observatory of Haute-Provence, France), and found that 52,3% were actually eclipsing binaries, while 2,3% were brown dwarfs. Santerne (IA & University of Porto), first author of this paper commented: “It was thought that the reliability of the Kepler exoplanets detection was very good – between 10 and 20% of them were not planets. Our extensive spectroscopic survey, of the largest exoplanets discovered by Kepler, shows that this percentage is much higher, even above 50%.
The news article above is unclear about the number of candidates total this study actually looked at and pinned down. It appears they began looking at the full database of almost 9,000 candidates, but then narrowed it to 125. Were 50% of the 9,000 false positives, or of the 125? The article is unclear.
At first glance, this study appears to tell us that there might be fewer giant Jupiter-sized exoplanets out there than previously thought. Then again, the data is uncertain enough that this conclusion could easily be wrong. The real take-away is that the science of exoplanets has only just begun, and that sweeping generalizations about the nature of solar systems in the galaxy are exceedingly unreliable. We simply don’t know enough yet.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Just think of the brown dwarfs and smaller stars in the binary systems as luminous planets and the uncertainty goes away.
Really? Your research capabilities amaze me. I suppose we can now abandon any further research effort, because you have explained everything astronomers are so unsure of, and thus have no need to waste our time trying to figure things out. MikeP knows, and can explain all!
Robert, I am not saying anything that they aren’t saying. They state that it is binary systems and binary systems including brown dwarfs that are causing “false positives” for planets. The “planets” in that half of the sample are thus orbiting stars. You could view such orbiting stars, in a sense, as luminous planets.
Perhaps it would be more useful to describe Kepler as successful in detecting eclipsing events but that those events were not necessarily planetary in origin. This is the reason that astronomers need to verify the cause of the eclipsing event. Only after verification by an alternate sensor can “dual phenomenology” be cited as reasonable certainty that an exoplanetary system has been identified.
Also remember that Kepler is useful only in detecting systems whose orbital plane aligns with our system. Frankly, I am surprised that they have found as many candidates as they have. (If you lived on Pluto, how long would you have to observe the sun before you observed any planet other than Mercury eclipsing the sun?) multiply that by (a billion?, a trillion?) to calculate the length of time required to observe a neighboring star to get even a glimpse of a transit of a planet orbiting at one AU.