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IAUC 5234: 1991N; N Her 1991; OJ 287

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IAUC number 

                                                  Circular No. 5234
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET    MARSDEN or GREEN@CFAPS2.SPAN


SUPERNOVA 1991N IN NGC 3310
     A. V. Filippenko, University of California at Berkeley, reports
that CCD spectra (range 310-980 nm, resolution 0.7-1.5 nm) obtained
on Apr. 7 UT with the Shane 3-m reflector at Lick Observatory show
that SN 1991N is of type Ic (or Ib) near maximum brightness.  The
continuum is relatively featureless, except for the P-Cyg Ca II
near-infrared triplet, O I 777.4-nm absorption, and broad emission
lines near 400 and 460 nm.  A few less obvious absorption lines
appear in the range 520-600 nm.  Contamination from the underlying H
II region is very strong.
     S. Korth, Monheim, Germany, reports the following visual magnitude
estimates of SN 1991N:  Apr. 2.92 UT, 13.9; 3.85, 14.1; 6.05,
14.5.


NOVA HERCULIS 1991
     R. M. Hjellming, National Radio Astronomy Observatory, communicates:
"A Very Large Array detection has been made of a radio counterpart
of Nova Her 1991 on Apr. 5.43 UT, at fluxes of 2.7, 1.9, and
1.3 mJy at frequencies of 14.9, 8.4, and 4.9 GHz.  This radio source
was undetected at 8.4 GHz on Mar. 28 and 31, with upper limits of
0.3 and 0.4 mJy, respectively.  The position of the radio source is
R.A. = 18h44m11s.86, Decl. = +12 10'45" (equinox 1950.0; uncertainty
of 1" in each coordinate), consistent with the position of the
optical nova (IAUC 5223)."
     A. Izumo, Yokohama Science Center, forwards the following
photoelectric observations by O. Oshima, Kurashiki, Japan:  Apr. 1.771
UT, V = 9.74 +/- 0.02, B-V = +0.38 +/- 0.03, U-B = -0.91 +/- 0.04;
Apr. 2.780, V = 10.06 +/- 0.02, B-V = +0.33 +/- 0.03, U-B = -0.94
+/- 0.05.


OJ 287
     M. R. Deshpande, A. K. Sen, U. C. Joshi, N. M. Vadher, A. B.
Shah, and J. S. Chauhan, Physical Research Laboratory, Navrangpura,
Ahmedabad, telex:  "We made white light photopolarimeteric observations
of the BL Lac object OJ 287 on Feb. 16-17 with the 2.3-m Vainu
Bappu Telescope at Kavalur.  The degree of polarization varied
between 14 and 19 percent (+/- 0.7 percent) with one prominent
periodicity around 6 min, in addition to 62-, 18-, and 4-min variations."


1991 April 9                   (5234)             Daniel W. E. Green

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