The ELODIE survey for northern extra-solar planets

Abstract

Abstract. Precise radial-velocity observations at Haute-Provence Observatory (OHP, France) with the ELODIE echelle spectrograph have been undertaken since 1994. In addition to several discoveries described elsewhere, including and following that of 51 Peg b, they reveal new sub-stellar companions with essentially moderate to long periods. We report here about such companions orbiting five solar-type stars (HD 8574, HD 23596, HD 33636, HD 50554, HD 106252) and one sub-giant star (HD 190228). The companion of HD 8574 has an intermediate period of 227.55 days and a semi-major axis of 0.77 AU. All other companions have long periods, exceeding 3 years, and consequently their semi-major axes are around or above 2 AU. The detected companions have minimum masses m 2 sin i ranging from slightly more than 2 M Jup to 10.6 M Jup . These additional objects reinforce the conclusion that most planetary companions have masses lower than 5 M Jup but with a tail of the mass distribution going up above 15 M Jup . The orbits are all eccentric and 4 out of 6 have an eccentricity of the order of 0.5. Four stars exhibit solar metallicity, one is metal-rich and one metal-poor. With 6 new extra-solar planet candidates discovered, increasing their total known to-date number to 115, the ELODIE Planet Search Survey yield is currently 18. We emphasize that 3 out of the 6 companions could in principle be resolved by diffraction-limited imaging on 8 m-class telescopes depending on the achievable contrast, and therefore be primary targets for first attempts of extra-solar planet direct imaging.

Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs

“…Both stars are similar to the Sun, but with ages less than about 2 Gyr based on isochrones (x 7.2). Precise radial velocity measurements indicate that HD 13507 also has a close companion (Perrier et al 2003). Pairs with large differences in T eA provide stronger constraints on abundance corrections, so we retained HD 131156 B in our abundance trend analysis, even though it is too cool (T eA ¼ 4592 K) to be in our main sample.…”

An extreme planetary system around HD 219828

“…A total of four observations were made with ELODIE between 1999 and 2004 as part of the ELODIE planet search program (Perrier et al 2003). The first of the four observations from the ELODIE database was made without a simultaneous thorium-argon lamp but observed within the same mode immediately before the constant star HD 220773.…”

The SOPHIE search for northern extrasolar planets

“…One of the different subprograms focuses on following-up the drifts and long-period signals detected within the ELODIE historical program initiated on the 1.93 m telescope at the Observatoire de Haute-Provence (OHP) by M. Mayor and D. Queloz in 1994. This program has monitored about 400 solar-type stars (from F5 to K0 dwarfs) in 12 yr and led to the detection of 24 exoplanets (e.g., Mayor & Queloz 1995;Perrier et al 2003;Naef et al 2004). In the past years, this program was focused on monitoring RV drifts that were identified as incomplete orbits of gravitationally bound companions.…”