GR Muscae explained
GR Muscae, also known as 2S 1254-690 is a binary star system in the constellation Musca composed of a neutron star of between 1.2 and 1.8 times the mass of the Sun and a low-mass star likely to be around the mass of the Sun in close orbit.[1] A magnitude 19 blue star was pinpointed as the optical counterpart of the X-ray source in 1978.[2] Its apparent magnitude varies from 18 to 19.1 over a period of 0.16 days.[3]
While the optical counterpart to the X-ray source was identified in 1978, optical variability was not detected until 1980, when a bright flare was seen that increased the white-light flux by a factor of two in a time interval of about 1.7 seconds.[4] GR Muscae received its variable star designation in 1985.[5]
The neutron star has an accretion disk that takes around 6.74 days to complete a revolution, and is inclined at an angle to the incoming stream of material from the donor star.[1]
Notes and References
- Cornelisse, R. . Kotze, M.M. . Casares, J. . Charles, P.A. . Hakala, P.J. . 2013. The Origin of the Tilted Disc in the Low-mass X-ray Binary GR Mus (XB 1254-690). Monthly Notices of the Royal Astronomical Society. 436. 1. 910–20. 1309.4972. 2013MNRAS.436..910C . 10.1093/mnras/stt1654 . free . 119242800 .
- Griffiths, R.E. . Gursky, H. . Schwartz, D.A. . Schwarz, J. . Bradt, H. . Doxsey, R.E. . Charles, P.A. . Thorstensen, J. R. . 1978. Positions and Identifications for Galactic X-ray Sources 2A1822-371 and 2S1254-690. Nature. 276. 16. 247–49. 1978Natur.276..247G . 10.1038/276247a0 . 4372341 .
- Web site: VSX : Detail for GR Mus . The International Variable Star Index . AAVSO.
- Mason . K. O. . Middleditch . J. . Nelson . J. E. . White . N. E. . An optical burst from the star identified with the X-ray source 2S1254-690 . Nature . 9 October 1980 . 287 . 5782 . 516-518 . 1980Natur.287..516M . 10.1038/287516a0 . 8 October 2024.
- Kholopov . P. N. . Samus . N. N. . Kazarovets . E. V. . Perova . N. B. . The 67th Name-List of Variable Stars . Information Bulletin on Variable Stars . March 1985 . 2681 . 1985IBVS.2681....1K . 8 October 2024.