Bibcode
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
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.