Circular No. 3833 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758 POSSIBLE COMET J. Davies telexes the discovery of another possible comet by the Infrared Astronomical Satellite. J. Gibson's June 30 confirmatory observation with the Palomar 1.2-m Schmidt telescope is semiaccurate, and he notes the image to be essentially stellar but "soft", a "central blur" with no condensation and no tail of total blue magnitude 15. The daily motion is Delta-R.A. = +1m1, Delta-Dec. = +21'.2. 1983 UT R.A. (1950.0) Decl. June 28.76004 01 22.40 -21 59.3 28.83153 01 22.48 -21 57.8 28.90323 01 22.64 -21 55.8 30.4754 01 24 17.6 -21 22 58 HO 139-68 N. Visvanathan, I. G. Tuohy and D. T. Wickramasinghe, Mount Stromlo and Siding Spring Observatories, telex: " Photometry and polarimetry of the AM-Her object HO 139-68 were obtained at optical wavelengths on June 5 for 2.5 hr with the Anglo-Australian Telescope at Siding Spring. The system was in an unusually faint state (B = 17) and a total light variation of less than 20 percent. The light was linearly polarized at a constant level (~ 6 percent) with nearly constant polarization angle. No linear polarization pulse was seen. The spectrum of this object, obtained by P. van der Kruit and K. C. Freeman on June 14 with the same telescope in the region 478.5-569.0 nm, showed weak H-beta emission and broad Zeeman components of H-beta in absorption corresponding to a field of 20 MG. There is also evidence for a weak MGB band, due to a late dwarf companion. Our observations show that HO 139-68 was in a rare state of very low activity. However, the presence of a high constant level of linar polarization is inconsistent with an origin in a white-dwarf photosphere at the suggested field of 20 MG. A more plausible explanation is in terms of optically-thin cyclotron radiation from two accreting poles, even at this low state." PERIODIC COMET TEMPEL 2 (1982d) Total visual magnitude estimate by J. E. Bortle, Stormville, NY (0.32-m reflector): June 9.32 UT, 10.5. 1983 July 1 (3833) Daniel W. E. Green
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