An Apparent Orbital Period Glitch in the Low Mass X-ray Binary EXO0748-676 Observed with USA and RXTE

Details An Apparent Orbital Period Glitch in the Low Mass X-ray Binary EXO0748-676 Observed with USA and RXTE An Apparent Orbital Period Glitch in the Low Mass X-ray Binary EXO0748-676 Observed with USA and RXTE

Oct 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000head....5.2404h&link_type=abstract

American Astronomical Society, HEAD Meeting #5, #24.04; Bulletin of the American Astronomical Society, Vol. 32, p.1217

Astronomy and Astrophysics

Astronomy

Scientific paper

We present 25 new eclipse timings of the low mass X-ray binary EXO0748-676 obtained with the USA experiment during 1999-2000 as well as 115 eclipse timings obtained with RXTE during 1996-2000. The mean orbital period has increased by 8 ms between the pre-RXTE era (1985-1990) and the RXTE/USA era (1996-2000). This corresponds to an orbital period derivative of 2 x 10-11. However neither a constant orbital period derivative nor any other simple ephemeris provides an acceptable fit: individual eclipse timings have residuals of up to 10 or more seconds. Eclipse profiles vary significantly as well. We conclude that mid-eclipse timings are not stable orbital phase markers. Several toy models to account for the change in orbital period, including tidal coupling, mass expulsion ( 7 x 10-8 solar masses over 15 years), spin down of either star (fractional change in frequency of 10-5 for companion star or 10-3 for neutron star over 15 years), and an asteroid crashing into the companion star ( 2500 km radius falling from infinity), are presented. None of the models is satisfactory. Basic research in X-ray Astronomy at the Naval Research is supported by the Office of Naval Research. This work has been supported by the National Aeronautics and Space Administration.

Affiliated with

Also associated with

No associations

Rating

An Apparent Orbital Period Glitch in the Low Mass X-ray Binary EXO0748-676 Observed with USA and RXTE does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with An Apparent Orbital Period Glitch in the Low Mass X-ray Binary EXO0748-676 Observed with USA and RXTE, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An Apparent Orbital Period Glitch in the Low Mass X-ray Binary EXO0748-676 Observed with USA and RXTE will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-871391