An atlas of cool supergiants from the Magellanic Clouds and typical interlopers. A guide for the classification of luminous red stars

Abstract

We present an atlas composed of more than 1500 spectra of late-type stars (spectral types from G to M) observed simultaneously in the optical and calcium triplet spectral ranges. These spectra were obtained as part of a survey to search for cool supergiants in the Magellanic Clouds and were taken over four epochs. We provide the spectral and luminosity classification for each spectrum (71% are supergiants, 13% are giants or luminous giants, 4% are carbon or S stars, and the remaining 12% are foreground stars of lesser luminosities). We also provide a detailed guide for the spectral classification of luminous late-type stars, the result of the extensive classification work done for the atlas. Although this guide is based on classical criteria, we have put them together and re-elaborated them for modern CCD-spectra as these criteria were scattered among many different works and mainly conceived for use with photographic plate spectra. The result is a systematic, well-tested process for identifying and classifying luminous late-type stars, illustrated with CCD spectra of standard stars and the classifications of our own catalogue.

Accepted for publication in A&A. The atlas of spectra and the complete list of targets will be available at CDS, once the paper is published

References in corpus (10)

• The Radial Velocity Experiment (RAVE): Fifth Data Release
• A massive cluster of Red Supergiants at the base of the Scutum-Crux arm
• Discovery of an Extraordinarily Massive Cluster of Red Supergiants
• The cool supergiant population of the massive young star cluster RSGC1
• A third red supergiant rich cluster in the Scutum-Crux Arm
• An LTE effective temperature scale for red supergiants in the Magellanic clouds
• A new survey of cool supergiants in the Magellanic Clouds
• Red supergiants around the obscured open cluster Stephenson 2
• Spectral type, temperature and evolutionary stage in cool supergiants
• Characterisation of red supergiants in the Gaia spectral range

Cited by in corpus (12)

• The young massive SMC cluster NGC 330 seen by MUSE. I. Observations and stellar content
• The Time-Averaged Mass-Loss Rates of Red Supergiants As Revealed by their Luminosity Functions in M31 and M33
• Multiplicity of the red supergiant population in the young massive cluster NGC 330
• Evolved Massive Stars at Low-metallicity II. Red Supergiant Stars in the Small Magellanic Cloud
• Lucky spectroscopy, an equivalent technique to Lucky Imaging: II. Spatially-resolved intermediate-resolution blue-violet spectroscopy of 19 close massive binaries using the William Herschel Telescope
• High-resolution spectroscopic study of massive blue and red supergiants in Per OB1
• Multiplicity among the cool supergiants in the Magellanic Clouds
• Cluster membership for the long period Cepheid calibrator SV Vul
• On the nature of VX Sagitarii: Is it a TZO, a RSG or a high-mass AGB star?
• Red supergiant stars in binary systems II. Confirmation of B-type companions of red supergiants in the Small Magellanic Cloud using Hubble ultra-violet spectroscopy
• Testing Evolutionary Models with Red Supergiant and Wolf-Rayet Populations
• The Properties of Fast Yellow Pulsating Supergiants: FYPS Point the Way to Missing Red Supergiants