THE ROSSITER-MCLANGHLIN ROTATION EFFECT OBSERVED FOR AI DRACONIS AND V505 SAGITTARII

Authors
Citation
Tf. Worek, THE ROSSITER-MCLANGHLIN ROTATION EFFECT OBSERVED FOR AI DRACONIS AND V505 SAGITTARII, Publications of the Astronomical Society of the Pacific, 108(729), 1996, pp. 962-966
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Publications of the Astronomical Society of the Pacific
ISSN journal
0004-6280 → ACNP
Volume
108
Issue
729
Year of publication
1996
Pages
962 - 966
Database
ISI
SICI code
0004-6280(1996)108:729<962:TRREOF>2.0.ZU;2-N
Abstract
CCD spectra were obtained for the late-B and early-A type Algol binari es Al Draconis and V505 Sagittarii during their 1991 May primary eclip ses. With these spectra, the Rossiter-McLaughlin rotation effect was o bserved. The least-squares fit to the rotation effect yielded projecte d rotational velocities of 85.6+/-2.1 and 131.8+/-2.8 km s(-1) and bar ycentric velocities of +5.5+/-0.4 and -0.8+/-0.6 km s(-1) for Al Dra a nd V505 Sgr, respectively. Compared to their synchronous values, Al Dr a appears to be rotating slightly more slowly while V505 Sgr is rotati ng considerably faster than expected. The eclipse spectra were also ex amined for signs of secondary and/or tertiary companions. The third st ar belonging to the V505 Sgr system which was discovered by Tomkin (19 92, ApJ, 387, 631) was easily recognized but no absorption features we re found that could be directly attributed with any certainty to the s econdary in either system. However, the Ca II K line in AI Dra was at times distorted and several weak, broad features were noted in V505 Sg r.