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
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Publications of the Astronomical Society of the Pacific
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.