Research Note

The evolutionary status of the UX Orionis star RZ Piscium

¹ Pulkovo Astronomical Observatory, Russian Academy of Sciences, 196140 Pulkovo St. Petersburg Russia
e-mail: grinin@gao.spb.ru; ilya-astro@yandex.ru
² The Sobolev Astronomical Institute, St. Petersburg University, Petrodvorets, St. Petersburg, Russia
³ Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Russia
e-mail: faig@sao.ru
⁴ Terskol Branch of the Institute for Astronomy of RAS, Terskol, Russia

Received: 29 April 2010
Accepted: 26 August 2010

Abstract

The star RZ Psc is one of the most enigmatic members of the UX Ori star family. It shows all properties that are typical for these stars (the light variability, high linear polarization in deep minima, the blueing effect) except for one: it lacks any signatures of youth. With the lithium line 6708 Å as a rough estimate for the stellar age, we show that the “lithium” age of RZ Psc lies between the age of stars in the Pleiades (~70 Myr) and the Orion (~10 Myr) clusters. We also roughly estimated the age of RZ Psc based on the proper motion of the star using the Tycho-2 catalog. We found that the star has escaped from its assumed birthplace near to the Galactic plane about 30−40 Myr ago. We conclude that RZ Psc is a post-UXOr star, and its sporadic eclipses are caused by material from the debris disk.