Pre--Main-Sequence Stars in the Young Cluster IC 2391 (original) (raw)

NASA/ADS

;

• Hartmann, Lee W. ;
• Jones, Burton F. ;
• McNamara, Brian R.

Abstract

Seven or eight new, late-type members of the poor open cluster IC 2391 are identified, and membership is confirmed for two other stars. The new members fall approximately along a 3 x 10 to the 7th yr isochrone, which is the age estimated for the cluster on the basis of it super main-seqence turnoff. Echelle spectra were obtained for the most probable cluster members. Most show H-alpha in emission and a strong Li 6707 A absorption line, and a few are rapid rotators. The Li abundances for cluster stars cooler than the sun are considerably less than the primordial Li abundance, providing the first direct evidence for substantial premain-sequence Li burning. The rotational velocities show a range from about 15 to 150 km/s, with a distribution of rotational velocities not significantly different from that observed for low-mass stars in the Pleiades.

Publication:

The Astrophysical Journal

Pub Date:

July 1989

DOI:

10.1086/167592

Bibcode:

1989ApJ...342..285S

Keywords:

• Open Clusters;
• Pre-Main Sequence Stars;
• Stellar Evolution;
• Stellar Spectrophotometry;
• Absorption Spectra;
• Abundance;
• Color-Magnitude Diagram;
• Echelle Gratings;
• H Alpha Line;
• Lithium;
• Astrophysics;
• CLUSTERS: OPEN;
• STARS: EMISSION-LINE;
• STARS: EVOLUTION;
• STARS: PRE--MAIN-SEQUENCE