SIMBAD references

Fainter standard stars are essential for the calibration of larger telescopes. This work adds to the calibration spectra (CALSPEC) database of 19 faint white dwarfs (WDs) with all-sky coverage and V magnitudes between 16.5 and 18.7. Included for these stars is a new ultraviolet (UV) Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph between 1150 and 3000 Å with a resolution of ∼500. Pure hydrogen WD models are fit to these UV spectra and to six-band HST/Wide Field Camera 3 photometry at 0.28-1.6 μm to construct predicted model spectral energy distributions covering wavelengths from 900 Å to the James Webb Space Telescope limit of 30 μm using well-established CALSPEC procedures for producing flux standards with the goal of 1% accuracy.