Show/Hide Menu
Hide/Show Apps
anonymousUser
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Açık Bilim Politikası
Açık Bilim Politikası
Frequently Asked Questions
Frequently Asked Questions
Browse
Browse
By Issue Date
By Issue Date
Authors
Authors
Titles
Titles
Subjects
Subjects
Communities & Collections
Communities & Collections
A photometric-spectroscopic analysis and the evolutionary status of the Algol-type binary U Coronae Borealis
Download
index.pdf
Date
2003-07-11
Author
Yerli, Sinan Kaan
Sarna, MJ
Zola, S
Smith, RC
Tovmassian, G
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
4
views
4
downloads
The prime purposes of this study are to obtain reliable orbital parameters for the Algol-type binary U Coronae Borealis (U CrB) and to explain the evolutionary status of this system. All observations of the primary star's radial velocity are consistent with the value K(1) = 58.6 +/- 2.0 km s(-1). Measurements of the radial velocity of the secondary component give K(2) = 185.2 +/- 5.0 km s(-1). Using the photometrically determined inclination of 78.7 +/- 0.3, the masses of the two stars are therefore deduced to be 4.74 +/- 0.28 and 1.46 +/- 0.06 M. for the primary and secondary components, respectively. Using all available observations, we discuss the origin and evolution of the close binary system U CrB. We derive the restrictions concerning masses and period from a general network of calculations of medium mass close binary evolution. Detailed models are calculated within the derived ranges, giving the most likely initial system parameters as and P(i) = 1.4 d. It turns out that the interactive evolution up to the present stage has been non-conservative. During its evolution, U CrB has lost about 14 per cent of its initial total mass (DeltaM similar to 1 M.) and around 18 per cent of its initial total angular momentum. We also examine the possibility of probing dynamo action in the mass-losing component of U CrB. We point out that, in order to maintain the evolution of U CrB in its later stages, which is presumably driven by stellar 'magnetic braking', an efficient mechanism for producing large-scale surface magnetic fields in the donor star is required. We suggest that observed X-ray activity in U CrB may be a good indicator of its evolutionary status and the internal structure of the mass-losing component.
Subject Keywords
Space and Planetary Science
,
Astronomy and Astrophysics
URI
https://hdl.handle.net/11511/38113
Journal
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
DOI
https://doi.org/10.1046/j.1365-8711.2003.06644.x
Collections
Department of Physics, Article