V803-AQUILAE - A NEWBORN W-URSAE MAJORIS SIAMESE TWIN

Citation
Rg. Samec et al., V803-AQUILAE - A NEWBORN W-URSAE MAJORIS SIAMESE TWIN, Publications of the Astronomical Society of the Pacific, 105(694), 1993, pp. 1441-1455
Citations number
22
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
105
Issue
694
Year of publication
1993
Pages
1441 - 1455
Database
ISI
SICI code
0004-6280(1993)105:694<1441:V-ANWM>2.0.ZU;2-A
Abstract
A complete photometric analysis of BVRI photometry of the physically c ompact, eclipsing binary V803 Aquilae is presented. Six mean epochs of minimum light were determined from observations covering three primar y and three secondary eclipses. A period study covering 54 years of ob servation or nearly 77,000 orbital revolutions reveals three distinct eras of constant period with two major period jumps of +0.1 s and -0.3 s. The light curves show that the primary and secondary eclipse depth s are identical in V, and are nearly identical in B, R, and I, indicat ing that the components have nearly the same temperatures. Standard ma gnitudes were determined and a reddening estimate was made. A simultan eous solution of the four light curves was computed using the Wilson-D evinney synthetic light-curve code. The solution indicates that the sy stem consists of twin approximately K4 stars in shallow contact with a fill-out factor of approximately 8%. A mass ratio of 1.000 was comput ed with a negligible temperature difference of only 6 K. Thus, based o n our purely photometric solution, V803 Aq1 is made up of ''Siamese'' (contact) twin components. Theory would indicate that the twins have j ust recently come into contact, and the lack of other equal-mass W Urs ae Majoris systems would indicate that it is in a very transient or un usual state.