Circular No. 2859 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 Western Union: RAPID SATELLITE CAMBMASS SUPERNOVA IN NGC 7723 D. Ya. Martynov, Sternberg Astronomical Institute, reports that this supernova (cf. IAUC 2858) was independently discovered by V. A. Lipovetskij on a plate taken at the Byurakan Observatory on Oct. 27. The magnitude was 14.5. X-RAY FLARE IN NORMA L. J. Kaluzienski, S. S. Holt, E. A. Boldt and P. J. Serlemitsos, Goddard Space Flight Center, report the detection of an x-ray flare in Norma with the Ariel 5 all-sky monitor. The best position is R.A. = 16h09m, Decl. = -52o.6 with an error circle of approximately 2o radius. The sources 3U 1702-36, 1636-53 and 1642-45 were simultaneously measured to within 1o of their known positions. The new source was half as bright as the Crab between Nov. 1 and Nov. 4. beta PERSEI A. Epstein, Center for Astrophysics, Harvard and Smithsonian Observatories, reports that the SAS-3 Group has observed an x-ray source coincident with the position of beta Per (Algol). The source was observed with the rotating modulation collimator experiment for a period of 3.2 x 10**4 s from Oct. 22.3 to 27.3 UT. A 12-sigma signal was observed, and the position has a 90-percent confidence error radius of 1' centered on the star. The intensity in the 1.7 to 6 keV range is approximately 1 count s**-1, which is equivalent to about 10**31 erg s**-1 for a source at 30 pc. This result is consistent with the upper limit reported previously (Canizares et al. 1973, Astrophys. J. 183, L91). There is some evidence for intensity variation during the observation period. theta1 ORIONIS A W. A. Feibelman, Goddard Space Flight Center, writes: "Following the announcement by Lohsen (1975, IAU Inform. Bull. Variable Stars No. 998) that the star theta1 Ori A is an eclipsing variable with a period of 196.25 days, some 60 Allegheny Observatory plates of the Trapezium region taken between 1963 and 1969 were searched for variability. On three nights (1966 Jan. 3-4 and 4-5, 1967 Jan. 30-31) theta1 Ori A was considerably fainter than theta1 Ori D. These minima fall about 10 days behind the midpoint of the period, which was confirmed to be 196.298 days by Strand (1975, IAU Inform. Bull. Variable Stars No. 1025). The present data strongly suggest a displaced, broader, secondary minimum of an eccentric orbit for theta1 Ori A. The next primary minimum is expected on 1975 Dec. 5 and should last about 24 hours, according to Lohsen and Strand, but the next secondary minimum should occur near 1976 Mar. 20 and be observable for at least 48 hours. Observations, including those of radial velocity, are urged for a duration of about one week beginning at the end of Nov. 1975 and again in the middle of March 1976." CYGNUS X-2 C. Chevalier, Observatoire de Meudon; S. A. Ilovaisky, Observatoire de Meudon and Centre d'Etudes Nucleaires de Saclay; and G. Branduardi and P. W. Sanford, Mullard Space Science Laboratory, report: "Analysis of photoelectric photometry of the optical candidate for Cyg X-2 (R.A. = 21h42m36s.91, Decl. = +38o05'27".9, equinox 1950.0; Giacconi et al. 1957, Astrophys. J. 148, L129) obtained at the Haute Provence Observatory and of x-ray observations of this source made with the Copernicus satellite in 1974 and 1975 indicates that the available data are consistent with a period of 13.6 days. The optical light curve, which shows intrinsic scatter, exhibits two maxima and two minima per period and has an amplitude of 0.4 magnitude in the B filter. The 1974 x-ray light curve, whose amplitude is of a factor of two, shows a minimum which coincides in phase with one of the optical minima. The 1975 x-ray curve, based on 12 days of observations in June, shows a smooth 45-percent flux modulation with an intensity maximum at midphase (phi = 0.5). Superposed on this are sharp x-ray 'dips' during which the source drops in intensity by as much as a factor of two. The mean optical brightness of Cyg X-2 in the B filter decreased from 1974 to 1975 by 0.3 magnitude, whereas the mean x-ray level increased by about 50 percent. Further correlated observations are in progress. R CORONAE BOREALIS Selected visual magnitude estimates: Oct. 24.0 UT, 7.9 (J. E. Bortle, Brooks Observatory); 25.0, 8.0 (Bortle); 27.97, 9.3 (A. C. Porter, Narragansett, Rhode Island); 28.0, 8.9 (Bortle); 29.0, 9.7 (Bortle); 29.74, 9.5 (N. A. v.d. Mey, Soesterberg, The Netherlands); 31.75, 9.9 (R. Lukas, Wilhelm Foerster Observatory). NOVA PERSEI 1974 Recent visual magnitude estimates: Sept. 29.1 UT, 13.3 (J. E. Bortle, Brooks Observatory); Oct. 3.83, 13.5 (G. M. Hurst, Northampton, England); 25.0, 13.6 (Bortle); 28.0, 13.4 (Bortle). 1975 November 6 (2859) Brian G. Marsden
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