CARMENES is the new optical/near-infrared spectrograph at Calar Alto observatory. The identification of the most promising targets for exoplanet hunting is a crucial first step to ensure an efficient use of the CARMENES guaranteed time. To achieve this, we obtained low-resolution (R ∼ 1500) spectra of 752 M (and late K) dwarfs, mostly fainter than J = 9 mag, using the CAFOS spectrograph of the 2.2 m telescope at Calar Alto observatory. We derived spectral types with 0.5 subtypes accuracy combining the spectral indices technique and the best-fit & χ^2 matches. We also studied metallicity and surface gravity through spectral indices, and activity from the pseudo-equivalent width of the Hα line. We identified high-activity, low-metallicity and low-gravity stars, which should be discarded for exoplanet searches. Here we present preliminary results.
Highlights of Spanish Astrophysics VIII
- Pub Date:
- May 2015