The Gaia-ASAS-SN Classical Cepheid Sample. I. Sample Selection

We present a well-defined and characterized all-sky sample of classical Cepheids in the Milky Way, obtained by combining two time-domain surveys: Gaia DR2 (Gaia Collaboration et al. 2018) All-Sky Automated Survey for Supernovae (ASAS-SN; Shappee 2014). first use parallax variability information from to select ∼30,000 bright (G < 17) Cepheid candidates with MK − 1. then analyze their ASAS-SN V-band light curves, determining periods classifying curves using Fourier parameters. This results ∼1900 likely Galactic Cepheids, which we estimate be ≳90% complete pure within our adopted selection criteria. is largest Way that has such well-characterized function, needed population modeling systematic spectroscopic follow-up foreseen Sloan Digital Sky Survey-V. About 130 these potential have not been documented literature even as possible candidates.