Extrasolar Visions II
Would you like to react to this message? Create an account in a few clicks or log in to continue.

Extrasolar Visions II

Extrasolar Planets.
 
HomeHome  SearchSearch  Latest imagesLatest images  RegisterRegister  Planet TablePlanet Table  Log in  

 

 HARPS search in the metal-poor sample

Go down 
3 posters
AuthorMessage
Borislav
Jovian
Jovian



Number of posts : 564
Registration date : 2008-11-12

HARPS search in the metal-poor sample Empty
PostSubject: HARPS search in the metal-poor sample   HARPS search in the metal-poor sample Empty10th November 2010, 2:55 am

http://arxiv.org/pdf/1011.2094

Quote :

5.3.4. Ambiguous cases: new candidate planets

HD107094: A total of 14 radial velocities were obtained for this star, showing a clear long-term (quasi-linear) radialvelocity signal. Twelve of these measurements were obtained within the HARPS GTO program, and a last two in July 2010 under ESO program 085.C-0063. In a first analysis, the total amplitude (∼2.5 kms−1 over 2355days) suggests there is a stellar or sub-stellar companion orbiting this 0.8 solar mass star. A single Keplerian fit to the data shows that it is well fit by a long-period Keplerian function, though the orbital parameters are difficult to constrain (see Fig. 11). The residuals of this fit, on the order of 2.1ms−1, are still high, and they called attention to a different possible orbital solution to the system. Indeed, a fit of the linear drift together with a Keplerian function reveals the presence of a possible shorter period solution, with P∼1870days, K=88ms−1, and e=0.13 (Table 5.3.4). This signal, first detected using only the GTO data, is compatible with the presence of a 4.5 Jupiter mass companion. The residuals of this fit (1.10ms−1) are significantly better than in the previous case. The fitted linear trend (which, to our knowledge,
has not been previously reported in the literature) has a slope of 402±1m/s/yr. More data are now
needed to disentangle the two possible solutions, but we are likely seeing a new giant planet. Interestingly, with [Fe/H]=−0.51 (Sousa et al. 2010), HD107094 is close to the high-metallicity limit of our sample.

HD197083: Although the statistical analysis done for this star does not indicate any strong signal, a visual inspection of the radial velocities hints at the presence of a long-term periodic signal (P∼1500-2000days), see Fig. 8. The number of points covering the first ∼1000 days is
very reduced (3) with high error bars. More data are thus clearly needed to confirm this signal.
Back to top Go down
Edasich
dK star
dK star
Edasich


Number of posts : 2289
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

HARPS search in the metal-poor sample Empty
PostSubject: Re: HARPS search in the metal-poor sample   HARPS search in the metal-poor sample Empty10th November 2010, 6:33 am

A yet unconfirmed planet. What a pity Laughing
Back to top Go down
Lazarus
dF star
dF star



Number of posts : 3337
Registration date : 2008-06-12

HARPS search in the metal-poor sample Empty
PostSubject: Re: HARPS search in the metal-poor sample   HARPS search in the metal-poor sample Empty10th November 2010, 3:16 pm

Looks like they haven't got sufficient data to determine an unambiguous orbital solution. Probably there is something there though.
Back to top Go down
Sponsored content





HARPS search in the metal-poor sample Empty
PostSubject: Re: HARPS search in the metal-poor sample   HARPS search in the metal-poor sample Empty

Back to top Go down
 
HARPS search in the metal-poor sample
Back to top 
Page 1 of 1
 Similar topics
-
» A Keck HIRES Doppler Search for Planets Orbiting Metal-Poor Dwarfs
» Planetary system around metal-poor star HIP 11952
» Compact multi-planet systems are more common around metal poor stars
» Metallicity-biased HARPS search
» HARPS-TERRA: new method of analysing HARPS spectra

Permissions in this forum:You cannot reply to topics in this forum
Extrasolar Visions II :: Extrasolar Visions :: Extrasolar News and Discoveries-
Jump to: