Abstract Details
| Name: CHETANA JAIN Affiliation: Hansraj College, University of Delhi Conference ID: ASI2017_1232 Title : Orbital decay of the low mass X-ray binary MXB 1658-298 and indication of a massive circumbinary planet from X-ray eclipse timing Authors and Co-Authors : Biswajit Paul (Raman Research Institute), Rahul Sharma (Delhi University), Abdul Jaleel (Delhi University), Anjan Dutta (University) Abstract Type : Oral Abstract Category : Stars,ISM and the Galaxy Abstract : We will present an X-ray eclipse timing of the transient X-ray binary MXB 1658-298, using data obtained with the RXTE and XMM-Newton observatories. We have made 27 new mid eclipse time measurements from observations made during the two outbursts of the source. These new measurements have been combined with the previously known values to study the long term changes in the orbital period of the binary system. We have found that as compared to other eclipsing LMXBs, the mid-eclipse timing record of MXB 1658-298 is quite unusual. The long term evolution of mid-eclipse times from the three outbursts, first of which was in 1976, indicates an overall orbital period decay. But, from a large number of observations made during the second outburst, the O-C residual curve shows a sinusoidal variation, which is indicative of the presence of a third body around the compact X-ray binary. The mass and orbital radius of the third body is estimated to be about 19 Jupiter mass and 745 lt-s respectively. If true, it is the most massive circumbinary planet and also the smallest period binary known to host a planet. The results have interesting implication for formation and migration of orbits of planets in binary stellar systems. |