Aquila X – 1 : a low inclination soft X - ray transient
نویسندگان
چکیده
We have obtained I-band photometry of the neutron star X-ray transient Aql X–1 during quiescence. We find a periodicity at 2.487 c d −1 , which we interpret as twice the orbital frequency (19.30±0.05 h). Folding the data on the orbital period, we model the light curve variations as the ellipsoidal modulation of the secondary star. We determine the binary inclination to be 20 • –31 • (90 per cent confidence) and also 95 per cent upper limits to the radial velocity semi-amplitude and rotational broadening of the secondary star to be 117 km s −1 and 50 km s −1 respectively.
منابع مشابه
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