I report the discovery that the 9th-magnitude Galactic-halo star BD+14∘3061 is a member of the rare class of luminous metal-poor "yellow post-AGB" stars. Its Gaia DR2 parallax implies an absolute magnitude of MV=−3.44±0.27, and it is a very high-velocity star moving in a retrograde Galactic orbit. BD+14∘3061 is a field analog of the half-dozen yellow PAGB stars known in Galactic globular clusters, which have closely similar absolute magnitudes. These objects are the visually brightest members of old stellar populations; their apparently narrow luminosity function makes them potentially useful as Population II standard candles. The spectral-energy distribution of BD+14∘3061 out to 22μm shows no evidence for circumstellar dust. The star is a low-amplitude semi-regular pulsating variable, with typical periods of 30-32 days. A radial-velocity study suggests that it is a spectroscopic binary with a period of 429.6 days, making it similar to known binary yellow PAGB stars such as HD 46703 and BD+39∘4926.
@article{arxiv.2010.06708,
title = {BD+14$^\circ$3061: A Luminous Yellow Post-AGB Star in the Galactic Halo},
author = {Howard E. Bond},
journal= {arXiv preprint arXiv:2010.06708},
year = {2020}
}