| NASA-UC Eta-Earth Survey | |
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: NASA-UC Eta-Earth Survey 10th March 2010, 6:43 pm | |
| http://kiaa.pku.edu.cn/Activities/planet09/files/ahoward_beijing_public.pdf - Quote :
- 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 - Quote :
- 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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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: NASA-UC Eta-Earth Survey 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 _________________ Caps Lock: Cruise control for 'Cool'!
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 10th March 2010, 7:16 pm | |
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 18th March 2010, 3:20 pm | |
| http://meetingorganizer.copernicus.org/EGU2010/EGU2010-6002.pdf - Quote :
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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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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: NASA-UC Eta-Earth Survey 18th March 2010, 3:32 pm | |
| With the exception of the 20 planets orbiting retired A stars, this sounds like old news. _________________ Caps Lock: Cruise control for 'Cool'!
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 18th March 2010, 3:42 pm | |
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 23rd April 2010, 8:20 am | |
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 10th October 2010, 10:11 am | |
| http://www.noao.edu/perl/abstract?2009A-0338 - Quote :
- 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 - Quote :
- 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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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 10th October 2010, 10:22 am | |
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 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... - Quote :
- 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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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: NASA-UC Eta-Earth Survey 28th October 2010, 7:21 pm | |
| _________________ Caps Lock: Cruise control for 'Cool'!
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 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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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: NASA-UC Eta-Earth Survey 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. _________________ Caps Lock: Cruise control for 'Cool'!
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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 29th October 2010, 3:00 am | |
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Lazarus dF star
Number of posts : 3337 Registration date : 2008-06-12
| Subject: Re: NASA-UC Eta-Earth Survey 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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Borislav Jovian
Number of posts : 564 Registration date : 2008-11-12
| Subject: Re: NASA-UC Eta-Earth Survey 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.jpgGeneva Group 163 stars. http://arxiv.org/abs/1011.0143Eta-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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