NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Discovery of orbital decay in SMC X-1Three observations of the binary X-ray pulsar SMC X-1 with the Ginga satellite, conducted on 3 days in 1987 May, 8.4 days in 1988 August-September, and 4 days in 1989 July-August, are reported. Based on the three observation epochs, the rate of change in the orbital period is estimated at (-3.36 +/- 0.02) x 10 exp -6/yr. An interpretation of the orbital decay is made in the context of tidal evolution with allowance for the effect of the increasing moment of inertia of the companion star due to its nuclear evolution. While the orbital decay is thought to be driven by tidal interactions, it is suggested that the asynchronism between the orbit and the rotation of the companion star is most likely maintained by the evolutionary expansion of the companion star (Sk 160) rather than via the Darwin instability.
Document ID
19930057235
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Levine, A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Rappaport, S.
(MIT Cambridge, MA, United States)
Deeter, J. E.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Boynton, P. E.
(Washington Univ. Seattle, United States)
Nagase, F.
(Inst. of Space and Astronautical Science Sagamihara, Japan)
Date Acquired
August 16, 2013
Publication Date
June 10, 1993
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 410
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
93A41232
Funding Number(s)
CONTRACT_GRANT: NAG8-762
CONTRACT_GRANT: NAG8-695
CONTRACT_GRANT: NAG8-207
CONTRACT_GRANT: NAGW-1545
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available