Position and Variability of {2A 1704+241}

Morgan, W. A., Jr.; Garcia, M. R.
Bibliographical reference

American Astronomical Society, HEAD Meeting #5, #24.07; Bulletin of the American Astronomical Society, Vol. 32, p.1218

Advertised on:
10
2000
Number of authors
2
IAC number of authors
0
Citations
0
Refereed citations
0
Description
We present results of analyses of observations of the X-ray source 2A 1704+241 with the ROSAT Position Sensitive Proportional Counter (PSPC) and the High Resolution Imager (HRI). 2A 1704+241 was first associated with the M-giant star HD 154791 based upon observations with the HEAO 1 SMC and the {Einstein} IPC and analysis of a spectrum of HD 154791 obtained with the International Ultraviolet Explorer. This identification was unusual because there are few bright X-ray binaries associated with an M-giant star. We observed {2A 1704+241} with the PSPC and the HRI in order to determine more accurately the position of the X-ray source and in order to study the previously-seen 900-second variability in the Einstein data. Based upon the previous identification and determination of the position of MS 1703.7+2417, an AGN in the field, and the position of three previously-unreported X-ray sources that we have associated with stars in the USNO-A2.0 catalog, we have confirmed the identification of the optical counterpart of the X-ray source {2A 1704+241} as HD 154791. In addition, we determine that there is little evidence for the 900-sec modulation seen by the Einstein IPC in the more recent PSPC data, and that there is no phase coherence in what modulation is noticeable.