NOAO >   Observing Info >   Approved Programs >   2017B-0213

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Program Information for 2017B-0213


PI: Alejandra Romero, UFRGS, aleromero82@gmail.com
Address: Departamento de Astronomia - IF, Av. Bento Gonçalves, 9500, Campus do Vale, 91540-000 - Porto Alegre - RS Brazil

CoI: S. O. Kepler, UFRGS
CoI: David Sanmartin, Gemini Observatory

Title: Spectroscopy of massive DB white dwarf candidate stars

Abstract: DB stars are He-rich atmosphere white dwarf stars, corresponding to ~13 % of the total population of white dwarfs. They show stellar masses in a narrow range, peaking around ~0.6 solar masses, similar to the H-rich atmosphere white dwarfs, but almost lacking objects with stellar masses above 0.95 solar masses. This implies a different and more rare formation chanel for massive DBs, than than of theur lower mass counterpart. To determine the stellar mass it is crucial to accurately measure the atmosphere parameters. We propose to observe massive DB candidates, classified as high log g white dwarfs from low signal-to-noise and low resolution spectra, to rule out possibe effects that could be leading to an over-estimation of the log g, and in this way confirm its massive nature.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2017B):  GEM-SQ/GMOSS -- 3hrs band 3 (GS-2017B-Q-72)


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NOAO >   Observing Info >   Approved Programs >   2017B-0213

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