NOAO >   Observing Info >   Approved Programs >   2018A-0131

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Program Information for 2018A-0131


PI: Alejandra Romero, UFRGS, alejandra.romero@ufrgs.br
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 stars

Abstract: DB stars are He-rich atmosphere white dwarf stars, corresponding to ~13% of the total pupolation of white dwarfs. They are found in a narrow range in stellar masses, peaking around ~0.6 solar masses, similar to hydrogen atmosphere white dwarfs, but with a very few objects with masses above 0.95 solar masses. This implies a different formation channel ofr further evolution for massive DB stars. To determine the stellar mass it is crucial to accurately measure the atmosphere parameters for massive BD stars. We propose to observe a small sample of massive DB candidates, classified as high log g white dwarfs from low signal-to-noise and low resolution spectra, to rule out possible effects that could be leading to an over-estimation of the log g, and confirm its massive nature.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2018A):  GEM-NQ/GMOSN -- 0.3hrs band 3 (GN-2018A-Q-308 )


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NOAO >   Observing Info >   Approved Programs >   2018A-0131

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