HP Lyr - Possibly the Hottest RV Tau Type Object

• Autorzy: Graczyk D. , Mikołajewski M. , Leedjärv L. , Frąckowiak S. M. , Osiwała J. P. , Puss A. , Tomov T.
• Języki publikacji: EN

Abstrakty

EN

We report Johnson's UBVRI photometric and optical spectroscopic observations of a long period variable HP Lyr which up to now has been considered to be an eclipsing binary with a period of 140 days. Its spectral type changes continuously from A2-3 at maxima to A7-F2 at minima. We propose that the brightness changes are caused by pulsation of the star with two periods: P₁=69.35 days, and P₂=2×P₁=138.7 days. These periods decreased by more than 1% between 1960 and 1980. The spectral luminosity class corresponds to 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) and high radial velocity (-113 km/s) indicate that HP Lyr is an evolved, most likely post-AGB star. All these features suggest that this star is an RV Tau type object.

Słowa kluczowe

EN

binaries: eclipsing; stars: oscillations; stars: individual: HP Lyr

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2002
• Tom: Vol. 52, No. 3
• Strony: 293--304
• Opis fizyczny: Bibliogr. 28 poz., tab., wykr.

Twórcy

autor

Graczyk D.

• Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87-100 Toruń, Poland
• Institute of Astronomy, Lubuska 2, 65-265 Zielona Góra, Poland

autor

Mikołajewski M.

• Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87-100 Toruń, Poland

autor

Leedjärv L.

• Tartu Observatory, 61602 Tõravere, Estonia

autor

Frąckowiak S. M.

• Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87-100 Toruń, Poland

autor

Osiwała J. P.

• Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87-100 Toruń, Poland

autor

Puss A.

• Tartu Observatory, 61602 Tõravere, Estonia
• Department of Physics, Tartu University, 4Tähe Street, 51010 Tartu, Estonia

autor

Tomov T.

• Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87-100 Toruń, Poland

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