Astronomy and Astrophysics – Astrophysics
Scientific paper
2002-02-23
Mon.Not.Roy.Astron.Soc. 333 (2002) 791
Astronomy and Astrophysics
Astrophysics
Accepted for publication in MNRAS
Scientific paper
10.1046/j.1365-8711.2002.05450.x
We present the results of our monitoring of the halo black-hole soft X-ray transient (SXT) XTE J1118+480 during its decline to quiescence. The system has decayed 0.5 mags from December 2000 to its present near quiescent level at R=18.65 (June 2001). The ellipsoidal lightcurve is distorted by an additional modulation that we interpret as a superhump of P_sh=0.17049(1) d i.e. 0.3% longer than the orbital period. This implies a disc precession period P_prec= 52 d. After correcting the average phase-folded light curve for veiling, the amplitude difference between the minima suggests that the binary inclination angle lies in the range i=71-82 deg. However, we urge caution in the interpretation of these values because of residual systematic contamination of the ellipsoidal lightcurve by the complex form of the superhump modulation. The orbital--mean H-alpha profiles exhibit clear velocity variations with ~500 km/s amplitude. We interpret this as the first spectroscopic evidence of an eccentric precessing disc.
Casares Jorge
Charles Phil A.
Foltz Craig B.
Hynes Robert I.
Rodríguez-Gil Pablo
No associations
LandOfFree
Detection of superhumps in XTE J1118+480 approaching quiescence 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 Detection of superhumps in XTE J1118+480 approaching quiescence, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of superhumps in XTE J1118+480 approaching quiescence will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-307973