Post-AGB Stars as Standard Extragalactic Candles
| dc.creator | Bond, Howard E. | |
| dc.date | 1997-02-01 | |
| dc.date.accessioned | 2026-07-07T02:22:51Z | |
| dc.date.available | 2026-07-07T02:22:51Z | |
| dc.description | Stars evolving off the asymptotic giant branch and passing through spectral types F and A are excellent candidates for a new extragalactic candle. These post-AGB (PAGB) stars are the brightest members of Population II systems. They should have a narrow luminosity function, bounded from above by the shorter transition times of more massive and more luminous remnants, and from below by the core mass corresponding to the lowest-mass stars that are leaving the main sequence. Moreover, PAGB A-F supergiants are easily recognized because of their enormous Balmer jumps, and should lie both in ellipticals and the halos of spirals. I describe a photometric system that combines Gunn u with the standard BVI bandpasses, and report a successful search for PAGB stars in the halo of M31 using this uBVI system. The zero-point calibration will come from PAGB A and F stars in Galactic globular clusters. Four are presently known, and have a mean Mv = -3.4 with a scatter of only 0.2 mag. With this Mv we exactly reproduce the accepted M31 distance from its halo PAGB stars. Future plans include a uBVI survey of Milky Way globular clusters and Local Group galaxies in order to strengthen the zero-point calibration. Ultimately we can reach the Virgo Cluster through a distance ladder with only three rungs: subdwarf parallaxes, Milky Way globular clusters, and then directly to Virgo (with HST). | |
| dc.description | 14 pages, 6 eps figures. To appear in "The Extragalactic Distance Scale", eds. M. Livio, M. Donahue, and N. Panagia (Cambridge University Press) | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9702008 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9702008 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/11031 | |
| dc.subject | Astrophysics | |
| dc.title | Post-AGB Stars as Standard Extragalactic Candles | |
| dc.type | text |