NASA-UC Eta-Earth Survey

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NASA-UC Eta-Earth Survey

Post by Borislav on 10th March 2010, 6:43 pm

http://kiaa.pku.edu.cn/Activities/planet09/files/ahoward_beijing_public.pdf
Progress on Eta-Earth Sample (2)
~80% of stars have 20+ observations
~80% of stars have 1 high-cadence run
~30 low-mass candidates being followed-up


Next Steps for Eta-Earth Survey
Finish survey observations (~6 months)
Intensive follow-up observations of best low-mass candidates
Announce more super-Earths and Neptunes!
Transit searches for announced and candidatelow-mass planets
Statistical study of low-mass / short-period exoplanets in Eta-Earth Survey

http://www.cfa.harvard.edu/events/2008/IAUS253/index/Oral_Porgram/IAU253_Oral_Abstracts.pdf
The Keck eta_Earth project
The Keck eta_Earth project seeks to detect and characterize a statistically significant sample of planets with masses between 3 and ~20 Earth masses. With 1 m/s radial-velocity precision, these measurements will provide one the first estimates of the fraction of stars with Earth-like planets. In all likelihood, some of these planets (with masses comparable to GJ436b, or smaller) will transit, offering rich opportunities for transit and secondary eclipse observations (of nearby, bright targets) to measure densities and constrain atmospheric/physical models of low-mass planets. This survey focuses on the nearest 250 GKM main sequence stars, all older than 2 Gyr (and hence chromospherically quiet), and accessible from Keck. Most of these stars have velocity rms under 2 m/s and are likely impoverished in detectable rocky planets within 0.1 AU. The remaining ~50 stars -- which are certainly enriched in rocky planets compared to the original 250 stars -- are observed on several ongoing high-cadence runs (7-10 consecutive nights) to identify the true planets and tease out their orbital characteristics. My presentation will focus on the transit-related aspects of this search, recent discoveries of super-Earths, and some initial constraints on the population of these objects.

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Re: NASA-UC Eta-Earth Survey

Post by Sirius_Alpha on 10th March 2010, 7:08 pm

I'm surprised there isn't already a thread on this project. Thanks.
For completeness, the first result from this programme:
HD 7924 b

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 10th March 2010, 7:16 pm

second result of the project
http://solar-flux.forumandco.com/extrasolar-news-and-discoveries-f2/new-super-earth-hd156668b-t494.htm

http://202.127.29.4/bdep_meeting/download/talks/20July/4-AHoward.ppt

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 18th March 2010, 3:20 pm

http://meetingorganizer.copernicus.org/EGU2010/EGU2010-6002.pdf

Updates from the California Planet Survey
We present the latest results from the California Planet Survey. The CPS a Doppler-based planet search at Lick and Keck Observatories that encompasses a wide variety of expolanetary science goals, and operates with a welldefined, publicly available star list and Exoplanet Database. Specific detections from this past year include 4 and 9 Earth-mass (msini) planets from the Eta-Earth program, three giant planets orbiting M dwarfs, updated multiplanet systems, five confirmed transiting planets from the Kepler mission, and 20 planets orbiting "retired" A-type stars. These discoveries have shed light onto the mass function of exoplanets over 3 orders of magnitude, increased our knowledge of planets beyond the ice line, revealed strong correlation between planet occurrence and stellar properties (metallicity and mass), and pointed the way to finding planets with the next generation of search methods such as direct imaging and astrometry.

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Re: NASA-UC Eta-Earth Survey

Post by Sirius_Alpha on 18th March 2010, 3:32 pm

With the exception of the 20 planets orbiting retired A stars, this sounds like old news.

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 18th March 2010, 3:42 pm


three giant planets orbiting M dwarfs


http://arxiv.org/abs/1001.1174
http://arxiv.org/abs/0912.2730

And what a third?

http://arxiv.org/abs/0809.0172 ?
But this is AAT, not Keck or Lick. And the year 2008.

Upd
http://exoplanets.org/papers/sixpack.pdf
Gl 179

So there are no surprises.

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 23rd April 2010, 8:20 am

http://online.kitp.ucsb.edu/online/exoplanets_c10/marcy/


15 red dots - the candidates for the planet

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 10th October 2010, 10:11 am

http://www.noao.edu/perl/abstract?2009A-0338

Abstract: M dwarfs comprise 70% of all nearby stars. They are by the principle targets of future interferometry (VLTI, SIM) and direct imaging missions. Due to the lower flux and mass of M dwarfs, Doppler programs that achieve 1 to 3 m/s precision are able to probe the habitable zone of these stars for planets as small as 2 earth-masses. Over the past 7 years we have received on average two nights per semester of NASA Keck time to survey the nearest 176 M dwarfs, resulting in most of the known M dwarf planets, the first neptune-mass planet, and the first terrestrial mass planet. This set of 176 stars has yielded 60 high priority stars that show evidence of terrestrial mass planets. These stars require higher observing cadence to confirm the existence of planets, and to break orbital aliases. Two NOAO nights per semester would allow us to triple the observing cadence on this set of sieved stars, from 1 to 3 nights per semester. This program will yield terrestrial mass planets around the nearest stars.

http://www.noao.edu/perl/abstract?2009B-0396
Two NOAO nights per semester would allow us to increase our observing cadence on this set of sieved stars, from 4 to 7 nights per year. This program will yield terrestrial mass planets around the nearest stars.

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 10th October 2010, 10:22 am

"This set of 176 stars has yielded 60 high priority stars that show evidence of terrestrial mass planets."

This estimate is close to the estimate of the Geneva group at HAPRS

http://online.kitp.ucsb.edu/online/exoplanets_c10/mayor/pdf/Mayor_ExoPlanetsConf_KITP.pdf
super-Earth are common around the red dwarf (>30%)

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 10th October 2010, 10:38 am

Although I think the correct meaning of the phrase California group that only about a third of stars have low chromospheric activity.

But hmmm...

These stars require higher observing cadence to confirm the existence of planets, and to break orbital aliases.

Then indeed there are 60 candidates system for small planets around red dwarf?

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Re: NASA-UC Eta-Earth Survey

Post by Sirius_Alpha on 28th October 2010, 7:21 pm

Eta-Earth results on the frequency of planets?

http://www.universetoday.com/76870/25-of-sun-like-stars-could-host-earth-sized-worlds/

Only 22 of the stars had detectable planets 33 planets in all


Great, PDF from the paper's supporting material.

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 29th October 2010, 12:58 am

But in general, their estimate of 2 times lower than that of the Geneva group.

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Re: NASA-UC Eta-Earth Survey

Post by Sirius_Alpha on 29th October 2010, 2:12 am

Borislav wrote:But in general, their estimate of 2 times lower than that of the Geneva group.
Since the Geneva group is making their claims based on actual detections, while the Eta-Earth group seems to be just extrapolating from the masses and abundance of the planets they detected, I'd think it's safe to say the HARPS number is better grounded in reality.

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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 29th October 2010, 3:00 am

No, of course, without extrapolation.

http://www.jpl.nasa.gov/news/news.cfm?release=2010-357
23% for the mass from 3 to 1000 Earth masses

http://online.kitp.ucsb.edu/online/exoplanets10/udry/oh/19.jpg
39-58%

Although it is likely this discovery of the Geneva group, without limit of the orbital period planets.
http://online.kitp.ucsb.edu/online/exoplanets_c10/mayor/oh/39.html
http://online.kitp.ucsb.edu/online/exoplanets_c10/mayor/oh/40.jpg

(Seems that only half of the planets of the Geneva group GTO sample have a period of less than 50 days).

http://www.sciencemag.org/cgi/data/330/6004/653/DC1/1
If we divide the planet (+ candidates) NASA-UC Eta-Earth Survey sample on two group:

T>50 days - 12(+5)
T<50 days - 17(+7)

Also about half Rolling Eyes

That's the way to confirm these words.
http://online.kitp.ucsb.edu/online/exoplanets_c10/mayor/oh/28b.html

This is a fresh slide from a presentation by the spring of 2010. Hence it is really 40-60% of the long-periodic candidates?

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Re: NASA-UC Eta-Earth Survey

Post by Lazarus on 29th October 2010, 5:23 pm

Incidentally Candidates 1-12 from the supplemental materials for the paper are now in the EPE unconfirmed section.
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Re: NASA-UC Eta-Earth Survey

Post by Borislav on 2nd November 2010, 2:20 pm

Borislav wrote:Hence it is really 40-60% with of the long-periodic candidates?

Looks this is really true.



If we restrict the candidates of the Geneva group 30 Earth masses and 0.2 astronomical units we obtain about 28 detections.



In the California group turns out also about 28 planets in this range (with missing).

The sample size is almost the same! :

http://online.kitp.ucsb.edu/online/exoplanets10/udry/oh/19.jpg
Geneva Group 163 stars.

http://arxiv.org/abs/1011.0143
Eta-Earth Survey 166 stars.

In general, the California group is probably less penetrated into the region for long-periodic (50-300 days) Neptunes and Super-Earths.

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Re: NASA-UC Eta-Earth Survey

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