Circular No. 3081 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Cable Address: SATELLITES, NEWYORK Telex: 921428 Telephone: (617) 864-5758 PERIODIC COMET WHIPPLE (1977h) Z. M. Pereyra, Cordoba Observatory, writes that he and J. Laborde have recovered this comet on plates taken with the 154-cm reflector at Bosque Alegre, as shown below. The comet is diffuse with central condensation. These observations confirm the tentative identification by C.-Y. Shao of a weak image of the comet on a single 40-min exposure obtained under poor conditions with the 155-cm reflector at the Harvard College Observatory's Agassiz Station. Positions are in good agreement with the ephemeris on IAUC 3036: 1977 UT R. A. (1950) Decl. m2 Observer May 16.32269 21 13 03.27 - 5 09 53.8 ~19.5 Shao 26.33462 21 18.78 - 4 18.6 19.8 Pereyra 26.37839 21 18.80 - 4 18.4 " HM SAGITTAE (EMISSION VARIABLE IN SAGITTA) 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. SUPERNOVA IN NGC 5406 Hurst also provides the following photovisual magnitude, derived by him from Tri-X exposures by B. Manning, Churchill, England, of Lovas' supernova (cf. IAUC 3053): Mar. 28.91 UT, ~ 14.5. 1977 June 8 (3081) Brian G. Marsden
Our Web policy. Index to the CBAT/MPC/ICQ pages.