XTE J1946+274 and 3A 1942+274
Abstract
T. Takeshima, NASA/Goddard Space Flight Center and Universities Space Research Association; and D. Chakrabarty, Massachusetts Institute of Technology, report: ''Scans of the region containing this transient x-ray pulsar (IAUC 7014) with the Proportional Counter Array (PCA) onboard RXTE on Sept. 16.23 UT have yielded the following improved position for the x-ray source: R.A. = 19h45m34s, Decl. = +27o23'.0 (equinox 2000.0). The error radius of 2'.4 (90-percent confidence level) is dominated by systematic uncertainties due to source intensity variations during the scans. The error circle almost includes the overlap of the RXTE/ASM error box for XTE J1946+274 (IAUC 7014) and the long Ariel V error strip for 3A 1942+274 (Warwick et al. 1981, MNRAS 197, 865). This strongly suggests that the two sources are identical. During the PCA observations on Sept. 16.24 and 17.57, the average source flux level and the pulse fraction stayed at about 110 mCrab and about 30 percent, respectively (2-60 keV). Observations at other wavelengths are encouraged in order to identify the mass donor."
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- September 1998
- Bibcode:
- 1998IAUC.7016....2T