Central Bureau for Astronomical Telegrams
IAUC 6245: 1995ah; R CrB
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Circular No. 6245
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 1995ah IN HS 0016+1449
C. C. Popescu, Max-Planck Institut fur Astronomie (MPIA),
Heidelberg; P. Rafanelli, Dipartimento di Astronomia, Padova; U.
Hopp, Universitatssternwarte Munchen and MPIA; and H. Elsasser,
MPIA, communicate: "During follow-up spectroscopy at the Calar
Alto 2.2-m telescope of emission-line galaxy candidates identified
on the digitized plates of the Hamburg Quasar Survey (Popescu et
al. 1995, A.Ap. Suppl., in press), we obtained two CCD spectra
(resolution 1.2 nm, range 380-860 nm) and a red CCD image of an
emission-line galaxy (redshift z = 0.0147) that we designate HS
0016+1449 (R.A. = 0h19m10s.9, Decl. = +15o06'23", equinox 2000.0).
A spectrogram obtained on 1995 Feb. 2.792 UT is dominated by the
features of a type-II supernova close to maximum brightness; the
spectrum of the supernova is characterized by broad emission lines
with P-Cyg absorption of the Balmer series and He I (587.6 nm) that
correspond to a range in expansion velocity of -20600 to -9000 km/s.
The FWZI of H-alpha is 20 700 km/s, and its centroid is blueshifted
by > 1050 km/s with respect to the systemic velocity. Two broad
emission blends centered at 455.0 and 524.0 nm in the rest frame
are also present. The Balmer lines are visible up to H-gamma. We
derive magnitudes for the supernova, estimated from its continuum
distribution: B = 17.6, V = 17.2. The red image obtained on 1995
Feb. 3.786 shows the supernova at the northern edge of a low-
surface-brightness dwarf galaxy with major axis of length 11".7
(axial ratio 0.73); SN 1995ah is located 1".6 east and 2".1 north
of the galaxy's center. The magnitude of the galaxy, as derived
from its spectrum, is B = 18.8, corresponding to absolute mag -15.1
(assuming the Hubble constant is 75 km sE-1 MpcE-1). An earlier
spectrogram, obtained on 1994 Oct. 8.141, shows energy distribution
and emission-line ratios typical of an H II galaxy where intensive
star formation is occurring [L(H-alpha) > 7 x 10E40 erg/s], with no
sign of the supernova's spectral signature. Morphology, absolute
magnitude, and spectrum classify HS 0016+1449 as a typical blue
compact dwarf galaxy."
R CORONAE BOREALIS
J. A. Mattei, AAVSO, reports that this variable has begun to
fade for the first time since Aug. 1993-Jan. 1994, when the star
reached mag 8.5 at minimum. Visual magnitude estimates: Oct. 1.03
UT, 6.1 (F. West, Hanover, PA); 6.80, 6.8 (A. Mizser, Budapest,
Hungary); 9.13, 7.2 (C. E. Spratt, Victoria, BC); 12.74, 7.9 (M. V.
Zanotta, Passo San Marco, Italy); 15.78, 9.1 (Zanotta); 17.72, 10.1
(L. Kiss, Szeged, Hungary).
1995 October 18 (6245) Daniel W. E. Green
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