Central Bureau for Astronomical Telegrams

IAUC 6271: 1995bb; OJ 287

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                                                  Circular No. 6271
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
Phone 617-495-7244/7440/7444 (for emergency use only)


SUPERNOVA 1995bb IN ANONYMOUS GALAXY
     S. Tokarz and P. Garnavich, Center for Astrophysics, report
their discovery of a supernova from the spectrum of an anonymous
galaxy observed for the 15R Redshift Survey directed by M. Geller:
"The galaxy (magnitude R about 15.0 via M. Kurtz) is an edge-on
spiral or irregular located at R.A. = 0h16m17s.64, Decl. =
+12o24'53".4 (equinox 2000.0).  A spectrum of the galaxy, taken by
P. Berlind on Nov. 29 using the Mt. Hopkins 1.5-m Tillinghast
telescope, shows a mixture of narrow and broad emission lines.  The
unresolved lines are identified as H II emission at z = 0.0058.
The most intense broad line is measured at 634.7 nm and is
identified as [O I].  Other, weaker emission features appear at
458.7, 593.7, and 734.8 nm and correspond to Mg I], Na I, and [Ca
II], respectively.  The overall spectrum is similar to that of the
type-Ib supernova 1985F, about 300 days after maximum (Schlegel and
Kirshner 1989, A.J. 98, 577).  The FWHM of the [O I] emission is
6600 km/s, while the Mg I] line has a FWHM of 4600 km/s.  The
visual absorption is 0.2-0.3 mag, based on the narrow-line Balmer
decrement.  Assuming a Hubble parameter of 65 km/s/Mpc, the [O I]
630.0-nm/636.3-nm luminosity is estimated to be 6 x 10E39 erg/s.
This implies a large oxygen mass, comparable to that of SN 1985F.
CCD images obtained by C. Prosser with the Mt. Hopkins 1.2-m
telescope on Dec. 7 shows the supernova coincident with the weak
galaxy nucleus.  The supernova may have reached mpg about 13 early
in 1995, and prediscovery observations are needed to determine the
time of maximum."


OJ 287
     M. Kidger, Instituto de Astrofisica de Canarias, reports that
OJ 287 is passing through an extended double-peaked outburst in
very close agreement with the date predicted by Lehto and Valtonen
(Ap.J., in press) for a binary black-hole model.  Recent data show
that this source is almost as bright as during the maximum a year
ago:  1995 Nov. 10.2 UT, V = 14.59 (P. Boltwood, Ottawa, Canada);
25.080, 14.73 (Y. Efimov, Crimea, Ukraine); Dec. 2.40, 15.09
(Boltwood); 3.92, 14.8 (L. Takalo, Tuorla, Finland); 4.25, 14.61
(Kidger); 5.27, 14.22 (T. Balonek, Colgate Obs., communicated by J.
Webb); 8.25, 14.28 (Takalo and K. Nilsson); 8.26, 14.27 (Boltwood).
M. Valtonen comments that the lightcurve's "double-peak structure
has been obvious in previous superflares as well, but in 1983 and
1984 the first peak was more prominent, while in 1994 the second
peak was higher."


1995 December 8                (6271)            Daniel W. E. Green

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