The Lick-Carnegie Survey: Four New Exoplanet Candidates

The Lick-Carnegie Survey: Four New Exoplanet Candidates

Quote :

We present new precise HIRES radial velocity (RV) data sets of five nearby stars obtained at Keck Observatory. HD 31253, HD 218566, HD 177830, HD 99492 and HD 74156 are host stars of spectral classes F through K and show radial velocity variations consistent with new or additional planetary companions in Keplerian motion. The orbital parameters of the candidate planets in the five planetary systems span minimum masses of M sin i = 27.43 M_{earth} to M sin i = 8.28 M_{jup}, periods of 17.05 to 4696.95 days and eccentricities ranging from circular to extremely eccentric (e ~ 0.63). The 5th star, HD 74156, was known to have both a 52-day and a 2500-day planet, and was claimed to also harbor a 3rd planet at 336d, in apparent support of the "Packed Planetary System" hypothesis. Our greatly expanded data set for HD 74156 provides strong confirmation of both the 52-day and 2500-d planets, but strongly contradicts the existence of a 336-day planet, and offers no significant evidence for any other planets in the system.

Of note, HD 74156 d does not exist.

Two of the four new objects are around stars already known to have a planet: HD 177830 and HD 99492 (83 Leo B). Period ratio of HD 177830 seems to be quite close to 3:11.

(Also I guess this means the EPE total is going to hit the big 500? 496 planets plus HIP 13044b and these four, minus HD 74156d...)

Lazarus wrote:

(Also I guess this means the EPE total is going to hit the big 500? 496 planets plus HIP 13044b and these four, minus HD 74156d...)

I think you're right.

The new companion of 83 Leo B is pretty nice. Seems to be the best RV Saturn-analogue yet know, if I'm not mistaken.

The guinness is achieved.

Quote :

Update : 19 November 2010 501 planets

Though the catalog lists 502. I don't know what kind of glitch is occurring at EPE.

Minus HD 74156d it works anyway.

Paper has been updated (link to v2), with some typos in the orbital parameters table corrected.