HP Lyr - possibly the hottest RV Tau type object
Abstract
We report Johnson's UBVRI photometric and optical spectroscopic observations of a long period variable HP Lyr which up to now has been considered an eclipsing binary with a period of 140 days. The spectral type changes continually from A2-3 at maxima to A7-F2 at minima. We propose that the brightness changes are caused by the pulsation of the star with two periods: P1=69.35, and P2=2xP1=138.7 days. These periods decreased by more than 1% between 1960 and 1980. The spectral luminosity class determination gives an A type supergiant Iab. HP Lyr is also the optical counterpart of the infrared source IRAS 19199+3950. Relatively high galactic latitude (b=+11.7 degr) and high radial velocity (-113 km/s) indicate that HP Lyr is an evolved, most likely post-AGB star. All presented features argue that this star is an RV Tau type object.
Keywords
Cite
@article{arxiv.astro-ph/0210448,
title = {HP Lyr - possibly the hottest RV Tau type object},
author = {Dariusz Graczyk and Maciej Mikolajewski and Laurits Leedjarv and Sylwia M. Frackowiak and Jedrzej P. Osiwala and Alar Puss and Toma Tomov},
journal= {arXiv preprint arXiv:astro-ph/0210448},
year = {2007}
}
Comments
13 pages, 10 figures