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IAUC 3833: Poss. COMET; HO 139-68; 1982d

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IAUC number

                                                  Circular No. 3833
Central Bureau for Astronomical Telegrams
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

     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. =

             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."

     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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