G. Pojmanski, Warsaw University Astronomical Observatory, reports thediscovery of a variable star on 'All Sky Automated Survey' images obtained with a 65-mm-aperture (180-mm-focal-length f/2.8) telephoto lens at Las Campanas on July 3.146 (at V = 11.98) and 5.239 UT (V = 11.19), with the position of the variable given as R.A. = 17h12m51s.3, Decl. = -30o56'39" (equinox 2000.0; CCD pixel size 14".8). Pojmanski reports that nothing was visible at this location on an ASAS image taken on June 27.219 (limiting mag V approximately 14.0). H. Yamaoka, Kyushu University, reports his measures for the new object from an image taken by G. Bolt (Craigie, Australia), yielding position end figures 51s.28, 37".6 (82 UCAC-2 reference stars; fitting error about 0".15 for each coordinate); Yamaoka adds that the nearest star visible in DSS images (and listed in the GSC 2.2 and 2MASS catalogues) is about 1" from this position. D. Nogami, Hida Observatory, Kyoto University, finds that there is no known x-ray source within 30" of the ASAS position, which suggests that it is not a dwarf nova. Nogami adds that a spectrum of the new object, taken by M. Fujii (Bisei, Okayama, Japan) on July 6.51, shows prominent Balmer emission lines (FWHM about 500 km/s for H_alpha, with possible P-Cyg profile); Na D absorption on a flat continuum is also clearly detected, which suggests moderate reddening. Nogami suggests that the spectrum resembles that of the slow nova V723 Cas (= N Cas 1995) during the pre-maximum halt phase (Iijima et al. 1998, A.Ap. 338, 1006). Additional magnitude estimates (partially forwarded by Yamaoka; visual unless noted otherwise): July 4.985, [11.8 (W. Liller, Vina del Mar, Chile, Technical Pan film + orange filter); 5.645, 11.3 (Bolt, unfiltered CCD; 0.06-mag rise in 2.7 hr); 6.052, R = 11.0 (P. Cacella, Brasilia, Brazil; CCD); 6.234, V = 10.92 (Pojmanski); 6.281, 11.1 (M. Linnolt, Honolulu, HI); 6.413, 10.8 (J. Bedient, Honolulu, HI); 6.463, B = 11.62, V = 10.83, R_c = 10.41, I_c = 10.00 (S. Kiyota, Tsukuba, Japan); 6.567, 10.9 (Y. Maeda, Nagasaki, Japan); 6.616, B = 11.44, V = 10.83, R_c = 10.33, I_c = 9.91 (H. Maehara, Saitama, Japan).
International Astronomical Union Circular
- Pub Date:
- July 2004