Letter to the Editor

The cool Galactic R Coronae Borealis variable DY Persei

¹ Institute of Atomic Physics and Spectroscopy, University of Latvia, Raiņa bulvāris 19, 1586 Rīga, Latvia e-mail: zacs@latnet.lv
² Graduate Institute of Astronomy, National Central University, Chung-Li 32054, ROC, Taiwan e-mail: wchen@astro.ncu.edu.tw
³ Special Astrophysical Observatory and Isaac Newton Institute of Chile, SAO Branch, Nizhnij Arkhyz 369167, Russia e-mail: faig@sao.ru
⁴ ICAMER, National Academy of Sciences of Ukraine, 361605 Peak Terskol, Kabardino-Balkaria, Russia
⁵ Shamakhy Astrophysical Observatory, National Academy of Sciences of Azerbaijan, Azerbaijan
⁶ 1.State Gimnazium of Riga, Raiņa bulvāris 8, 1050 Rīga, Latvia e-mail: tamara@r1g.edu.lv

Received: 1 March 2005
Accepted: 28 April 2005

Abstract

Results of first CCD photometry during the recent deep light decline, and high-resolution spectroscopy, are presented for DY Persei. The spectra show variable blueshifted features in the sodium D lines. The C i lines are strong whereas neutron-capture elements are not enhanced. The isotopic ¹³CN(2, 0) lines relative to ¹²CN are of similar strength with those for the carbon star U Hya. All these confirm the RCB nature of DY Per and the existence of ejected clouds. At least two clouds are revealed at -197.3 and -143.0 km s^-1. A star was detected about 04 to the west and 25 to the north from DY Per. This anonymous companion, with observed colour indices and , may be a foreground star.