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IAUC 4021: Poss. SN IN NGC 3675; PG 1346+082; 1984s

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                                                  Circular No. 4021
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 617-495-7244/7440/7444

     H. Kosai, Tokyo Astronomical Observatory, telexes that on
Dec. 2.826 UT Kaoru Ikeya, Maisaka, Shizuoka, discovered a possible
supernova, of mv = 13, in NGC 3675.  Further observations by
the discoverer on Dec. 3.778, 4.781 and 8.819 again showed the
object at mv = 13.  The position of the object was measured by H.
Shibasaki on an exposure on Dec. 4.775 UT with the 0.5-m Schmidt
at the Dodaira station to be: R.A. = 11h23m23s82, Decl. = +43deg51'36"2
(equinox 1950.0).  The corresponding position of the nucleus of
NGC 3675 was measured to be R.A. = 11h23m25s09, Decl. = +43deg51'30"2.

PG 1346+082
     R. E. Nather, M. A. Wood and D. E. Winget, University of
Texas; and J. Liebert, University of Arizona, write: "This purehelium
Palomar-Green object (R.A. = 13h46m25s9, Decl. = +8deg12'27",
equinox 1950.0) is both a photometric and a spectroscopic variable.  The
V magnitude varies from a minimum of 17.5 to a maximum of 13.0.  The
object was brighter than Vpg = 14.0 on 59 percent of ~ 1300 archival
plates spanning 6 yr; the minima are irregularly spaced and
separated by intervals of the order of weeks.  The mean colors are
U-B = -0.90, B-V = -0.09.  We have observed coherent photometric
periodicities of 745 and 1490 s with amplitudes 0.01 to 0.04 mag.
Optical spectra obtained near maximum are characterized by broad
(~ 10 nm), shallow (~ 9 percent) He I absorption lines; spectra
obtained near minimum are essentially featureless continua.  We
detect no He II features in any of our spectra.  Large-amplitude
photometric variations, coupled with the presence of ~ 2.5 percent
flickering at low state, indicate mass transfer in a binary system.
The absence of detectable hydrogen suggests that the
masslosing star is evolved--possibly an sdO or a white dwarf."

     Total visual magnitude estimates: Nov. 17.18 UT, 11.1 (J.
DeYoung, Troy, VA, 0.20-m reflector); 20.04, 11.4 (J. Bortle,
Stormville, NY, 0.32-m reflector); 23.06, 11.4 (Bortle); 26.20,
10.8 (C. S. Morris, Whitaker Peak, CA, 0.25-m reflector); 28.79,
11.2 (J.-C. Merlin, Le Creusot, France, 0.26-m refractor).

1984 December 12               (4021)              Brian G. Marsden

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