White Dwarfs

The white dwarf program in the MWM survey is obtaining multi-epoch BOSS spectra of a large sample of Galactic white dwarfs. These Earth-sized (and consequently intrinsically dim) objects are difficult to identify among the field of much brighter stars. Parallaxes from Gaia have been the key to identifying a homogeneous all sky sample of white dwarfs for spectroscopic follow-up

Spectra of white dwarfs
Examples of magnetic WD spectra from SDSS observations (Schmidt et al. 2003)

The white dwarf program draws its sample from the Gaia DR2 catalog of white dwarfs (Gentile Fusillo et al. 2019), selecting all targets with a greater than 50% probability of being a white dwarf that are brighter than 20th magnitude in the Gaia DR2 G passband.

Cartons


mwm_wd_core

The white dwarf program has a single carton with objects observed both with plates in targeting plan 0.1.0 and with the FPS under targeting plan 0.5.0. The following simple selection function uses Gaia DR2 photometry and the probability of being a white dwarf (PWD) from the catalog of Gentile Fusillo. That catalog can be queried on CasJobs and has been included in the SAS as mos_gaia_dr2_wd.fits.

  • G < 20
  • PWD > 0.5

Cadences

All white dwarf targets are observed with the BOSS instrument. In plate operations, they could be observed on plates with any cadence except the RM cadence.

During FPS, the carton used the dark_2x1 cadence.

Back to Top