Shao also provides the following position for this object (cf. IAUC 2995): R.A. = 19h39m41s.40, Decl. = +16o37'33".1 (equinox 1950.0). P. A. Feldman, Herzberg Institute of Astrophysics, reports that an observation with the 46-m radio telescope at the Algonquin Radio Observatory on May 9.4 UT showed emission (at 10.5 GHz) of flux density 21 +/- 5 mJy from a source consistent with the above precise position (which was not then available to him) of HM Sge. On May 17.3 UT the flux density had increased to 42 +/- 4 mJy. On 1976 Nov. 23.1 UT, however, no radio emission had been detected from this region. He suggests that HM Sge may present an unprecedented opportunity to study the emergence of an embryonic planetary nebula (see also Stover and Sivertsen 1977, Astrophys. J. 214, L33; Ciatti et al. 1977, Astron. Astrophys. in press) and strongly urges that further observations be made at all possible wavelengths. G. M. Hurst, Northampton, England, provides the following visual magnitude estimate: Apr. 2.16 UT, 11.2.
International Astronomical Union Circular
- Pub Date:
- June 1977