TEMPOS is assembling a far-ultraviolet and optical spectral atlas of O stars to anchor
stellar models at 5-10% solar metallicity.

Check back soon for science-ready COS spectra in DR1.

About the TEMPOS Survey

TEMPOS is a Large Treasury Hubble Space Telescope (HST) Program (GO-17491) to build a comprehensive library of far-ultraviolet (FUV) spectra of individual O stars in nearby dwarf galaxies below 20% Solar metallicity. By strategically taking new observations with the Cosmic Origins Spectrograph (COS) to complement data already in the HST archive, TEMPOS will produce a science-ready, legacy dataset of FUV spectra and reduced ancillary observations for the community to enable new investigations of massive stars and the interstellar medium at very low metallicity.

TEMPOS is also collecting new ground-based optical spectroscopy to enable measurements of stellar properties from the COS spectra using the DEIMOS spectrograph on the Keck II Telescope. Our major scientific goals are to empirically calibrate mass-loss models below 20% Solar metallicity and produce data-driven ionizing spectral templates suitable for modeling observations of metal-poor galaxies, including low-mass dwarf galaxies and high-redshift galaxies that contributed to the ionizing photon budget during the epoch of reionization.