Circular No. 3221 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 OCCULTATION OF SAO 85009 BY (2) PALLAS ON 1978 MAY 29 Recent predictions received from G. E. Taylor, H.M. Nautical Almanac Office, and from D. W. Dunham, Silver Spring, Maryland, indicate that the calculation by Wasserman and Franz (IAUC 3141) is essentially correct. Occultation time ranges from 5h21m UT off the eastern coast of North America to 5h27m UT off the western coast. Last-minute astrometric observations that could improve the predictions should be communicated forthwith, preferably by telex, either to U.K. telex 87451 (answerback RGOBSY G) URGENT ATTN. G. TAYLOR HMNO, or to U.S.A. telex 89675 (answerback NASCOM GBLT) URGENT ATTN. W. WARREN, CODE 601, NSSDC. Last-minute predictions will be available by telephoning Mr. Taylor during May 28d13h-28d16h UT at U.K. 032-181-3255 or by telephoning Dr. Dunham on May 27 or 28 at U.S.A 301-585-0989. Owing to the absence abroad of the undersigned, the Central Telegram Bureau will not be able to relay astrometric observations or to provide last-minute predictions. POSSIBLE SUPERNOVA IN MCG -4-32-23 G. Gilmore, Department of Physics, University of Canterbury, reports the discovery of a possible supernova 20" due west of the nucleus of a fifteenth-magnitude galaxy, presumably MCG -4-32-23, located at R.A. = 13h27m.5, Decl. = -21o29' (equinox 1950.0). The object, of magnitude about 17, appeared on May 8 and 9 as a distorted or secondary nucleus of the galaxy. It was not visible on exposures obtained on Mar. 9 and Apr. 8. POSSIBLE OPTICAL COUNTERPART OF 2S 1702-363 E. J. Zuiderwijk, University of Amsterdam and European Southern Observatory, reports: "On May 8.3 UT a blue stellar object was seen in the vicinity of the x-ray source 2S 1702-363. The object was discovered during spectroscopic observations at the Cassegrain focus of the 360-cm E.S.O. reflector. It was clearly visible on the integrating television guiding system and was brighter than the stars marked 1 and 2 in the finding chart given by Jernigan et al. (1978, Nature 272, 701). Its position is 8' east of star 2. Tests with blue and visual filters showed that the object was very blue (magnitude ~ 16.5). However, the object is not visible on either an ultraviolet or an H-alpha plate (38 A) taken at the prime focus of the 360-cm reflector on May 6.3 UT, even though star 1 is clearly visible on both plates. The object is also not present on the E.S.O. "quick blue" sky survey. An image-tube spectrogram (dispersion 114 A/mm) revealed a featureless spectrum with some indication of emission at H-beta." Mk 421 = 2A 1102+384 G. J Fishman, National Aeronautics and Space Administration, writes that the HEAO-1 spacecraft is scheduled to observe the BL Lac object Mk 421 = 2A 1102+384 during May 28d03h-28d12h UT. Optical and radio monitoring of the source near this time would be desirable. HEAO-1 pointed observations are continuing to be made about 5 times per week for intervals of 3 to 9 hours. F. Walter and K. O. Mason, University of California at Berkeley; and G. Garmire, California Institute of Technology, report that the HEAO low-energy detectors have also observed a soft source near Mk 421 on serveral scans during 1977 Nov. 23-25 (cf. IAUC 3212). The 0.2-2.0-keV flux was ~ 10**-10 erg cm**-2 s**-1, while a thermal bremsstrahlung spectral fit yielded a temperature in the range 2 to 5 x 10**6 K and NH = 1 to 4 x 10**20 atoms cm**-2. The 94-percent error-box coordinates are: R.A. = 11h02m00s, Decl. = +38o29'; 11h01m26s, +38o16';10h59m10s, +38o29'; 10h59m43s, +38o42' (equinox 1950.0). Mk 421 lies on the edge of this box. PERIODIC COMET WILD 2 (1978b) Further precise positions have been reported as follows: 1978 UT R. A. (1950) Decl. Mag. Observer Feb. 8.89723 5 15 53.76 +20 28 03.6 12 Clough 9.07987 5 15 54.89 +20 28 35.4 Penhallow 10.10589 5 16 01.90 +20 31 31.0 " 12.07568 5 16 23.42 +20 37 14.9 " Apr. 5.8882 6 22 17.60 +23 03 16.8 ~12.5 Manning 12.8802 6 37 42.23 +23 06 49.1 ~12.5 " 12.8948 6 37 44.0 +23 06 52 " H. Clough and R. H. McNaught (Macnairston Observatory) and B. Manning (Stakenbridge). Measurer: P. Birtwhistle. Communicated by G. M. Hurst. W. S. Penhallow (University of Rhode Island, Quonochontaug Station). Measurers: Q. V. Tran and B. M. Ashworth. Total visual magnitude estimates: Apr. 13.08 UT9 11.2 (S. O'Meara, Harvard College Observatory, 23-cm refractor); 15.05, 11.3 (O'Meara); 19.04, 11.3 (O'Meara; fantail 3' long in p.a. 0o-35o); 26.07, 10.7 (J. Bortle, Brooks Observatory, 32-cm reflector); May 1.08, 10.6 (Bortle); 3.06, 11.1 (O'Meara); 8.12, 11.2 (C. S. Morris, Harvard College Observatory, 23-cm refractor); 11.15, 10.7 (P. L. Collins, Mount Hopkins, Arizona, 20-cm reflector). 1978 May 18 (3221) Brian G. Marsden
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