Ugrás a tartalomhoz

 

A new sdO+dM binary with extreme eclipses and reflection effect

  • Metaadatok
Tartalom: http://dx.doi.org/10.1088/0004-637X/808/2/179
Archívum: MTA Könyvtár
Gyűjtemény: Status = Published

Type = Article
Cím:
A new sdO+dM binary with extreme eclipses and reflection effect
Létrehozó:
Derekas, A.
Németh, P.
Southworth, J.
Borkovits, T.
Sárneczky, K.
Pál, A.
Csak, B.
Garcia-Alvarez, D.
Maxted, P. F. L.
Kiss, László
Vida, Krisztián
Szabó, M. Gy.
Kriskovics, L.
Dátum:
2015
Téma:
QB Astronomy, Astrophysics / csillagászat, asztrofizika
Tartalmi leírás:
We report the discovery of a new totally-eclipsing binary (RA=06:40:29.11; Dec=+38:56:52.2; J=2000.0; Rmax=17.2 mag) with an sdO primary and a strongly irradiated red dwarf companion. It has an orbital period of Porb=0.187284394(11) d and an optical eclipse depth in excess of 5 magnitudes. We obtained two low-resolution classification spectra with GTC/OSIRIS and ten medium-resolution spectra with WHT/ISIS to constrain the properties of the binary members. The spectra are dominated by H Balmer and He II absorption lines from the sdO star, and phase-dependent emission lines from the irradiated companion. A combined spectroscopic and light curve analysis implies a hot subdwarf temperature of Teff(spec) = 55 000 +/- 3000K, surface gravity of log g(phot) = 6.2 +/- 0.04 (cgs) and a He abundance of log(nHe/nH) = -2.24 +/- 0.40. The hot sdO star irradiates the red-dwarf companion, heating its substellar point to about 22 500K. Surface parameters for the companion are difficult to constrain from the currently available data: the most remarkable features are the strong H Balmer and C II-III lines in emission. Radial velocity estimates are consistent with the sdO+dM classification. The photometric data do not show any indication of sdO pulsations with amplitudes greater than 7mmag, and Halpha-filter images do not provide evidence of the presence of a planetary nebula associated with the sdO star.
Típus:
Article
PeerReviewed
info:eu-repo/semantics/article
Formátum:
text
Azonosító:
Derekas, A. and Németh, P. and Southworth, J. and Borkovits, T. and Sárneczky, K. and Pál, A. and Csak, B. and Garcia-Alvarez, D. and Maxted, P. F. L. and Kiss, László and Vida, Krisztián and Szabó, M. Gy. and Kriskovics, L. (2015) A new sdO+dM binary with extreme eclipses and reflection effect. Astrophysical Journal, 808 (179).
Kapcsolat:
269194 (IRSES/ASK) and no. 312844 (SPACEINN)