Volume 399, Number 2, February IV 2003
|Page(s)||699 - 702|
|Section||Stellar structure and evolution|
|Published online||07 February 2003|
A possible 38 day X-ray period of KS 1731-260
Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117810 Moscow, Russia,
2 Max-Planck-Institute für Astrophysik, Karl-Schwarzschild-Str. 1, 85740 Garching bei München, Germany
Corresponding author: M. Revnivtsev, email@example.com
Accepted: 5 December 2002
We report the detection of a 38 day period of the X-ray transient and X-ray burster KS 1731-260. The periodicity was detected during Mar.1996-Aug.1998 (~TJD 10150-11050) when the source had a high and relatively stable X-ray flux. After Sep.-Oct. 1998 (~TJD 11100) the source became strongly variable on a time scale of months that contaminates the search for the 38 day periodicity. The detected period can not be a binary period. A binary with Roche lobe overflow has in this case large radii of the secondary and of the accretion disk. Illumination of the disk and secondary star by the X-ray flux from the luminous neutron star and inner disk, would lead to a high infrared brightness of the binary. That clearly contradicts the infrared data even for the brightest infrared sources within CHANDRA error box of KS 1731-260. A remaining possibility is that observed periodicity is connected with the accretion disk precession, similar to that was observed for, e.g. SS 433 and Her X-1.
Key words: accretion, accretion disks / stars: individual: KS1731–260 / stars: binaries: general / stars: neutron / X-ray: stars
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.