Circular No. 6321
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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GRO J1744-28

K-band photometry of stars A-D

P. Blanco, University of California, San Diego; C. Lidman, European Southern Observatory (ESO); and K. Glazebrook, Anglo- Australian Observatory, report photometry in the K band (2.2 microns) for objects in the vicinity of the radio-source candidate for GRO J1744-28 (IAUC 6307, 6308): "These measurements were made on a co-added image (600 s total exposure) taken on Feb. 8 UT at the ESO 2.2-m telescope (+ IRAC2); this image provided the preliminary K-band flux and source identifications reported on IAUC 6315. Using the same nomenclature, we have determined the following K magnitudes: star A, 13.1; star B, 14.0; star C, 13.3; star D, 11.3. At this wavelength, 0.0 mag corresponds to 620.0 Jy. To aid calibration in the ongoing searches for near-infrared variability, we also report magnitudes for three nearby isolated stars in our image: R.A. = 17h44m34s.0, Decl. = -28o45'07" (equinox 2000.0), K = 11.86; position end figures 37s.3, 50", 11.75; 37s.6, 12", 11.88. Although our absolute fluxes have uncertainties of +/- 0.25 mag, photometry of sources A-D relative to these brighter stars should be accurate to +/-0.1 mag, except for star B (+/-0.3 mag), which is faint and confused with star D."

For more information, see the GROJ1744-28 WWW page.