Photometric Observations of Three High Mass X-Ray Binaries and a Search for Variations Induced by Orbital Motion

TL;DR

This study investigates long-term optical and X-ray variability in three high mass X-ray binaries to detect orbital motion effects, finding suggestive but inconclusive evidence of periodic variations.

Contribution

The paper provides a comprehensive analysis of long-term light curves from multiple sources to search for orbitally induced variations in HMXBs, highlighting the need for extended, precise observations.

Findings

Fourier analysis suggests possible long period variations.

No definitive periodic variation was confirmed.

Higher precision, long-term data may reveal subtle variations.

Abstract

We searched for long period variation in V-band, Ic-band and RXTE X-ray light curves of the High Mass X-ray Binaries (HMXBs) LS 1698 / RX J1037.5-5647, HD 110432 / 1H 1249-637 and HD 161103 / RX J1744.7-2713 in an attempt to discover orbitally induced variation. Data were obtained primarily from the ASAS database and were supplemented by shorter term observations made with the 24- and 40-inch ANU telescopes and one of the robotic PROMPT telescopes. Fourier periodograms suggested the existence of long period variation in the V-band light curves of all three HMXBs, however folding the data at those periods did not reveal convincing periodic variation. At this point we cannot rule out the existence of long term V-band variation for these three sources and hints of longer term variation may be seen in the higher precision PROMPT data. Long term V-band observations, on the order of several years, taken at a frequency of at least once per week and with a precision of 0.01 mag, therefore still have a chance of revealing long term variation in these three HMXBs.