Central Bureau for Astronomical Telegrams
IAUC 6142: G299.2-2.9; 1995E; Notice
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Circular No. 6142
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)
Phone 617-495-7244/7440/7444 TWX 710-320-6842 ASTROGRAM CAM
MARSDEN@CFA.HARVARD.EDU or GREEN@CFA.HARVARD.EDU (science)
G299.2-2.9
J.-U. Busser, R. J. Egger, and B. Aschenbach, Max-Planck-
Institut fur Extraterrestrische Physik, Garching, report: "A new
supernova remnant, G299.2-2.9, centered at R.A. = 12h15m11s.6, Decl.
= -65o30'04" (equinox 2000.0), has been discovered in the ROSAT All-
Sky Survey. G299.2-2.9 is nearly circular with a diameter of 15'
and has a centrally-filled shape. The European Southern Observatory's
red survey plate No. 92 shows nebulous filaments around the
rim of the source, which also shows up as a ring in the 60- to 100-
micron IRAS ratio map. No radio counterpart has been found in
available radio catalogues. A thermal plasma model best fit reveals
a temperature of about 8 x 10E6 K and a column density of NH about
3 x 10E20 cmE-2. With a mean interstellar H I density of 0.2 cmE-3,
the distance to G299.2-2.9 is about 500 pc. The observed count
rate in the ROSAT band (0.1-2.4 keV) is 3.3 counts/s and the
equivalent unabsorbed energy flux is 2.3 x 10E-11 erg cmE-2 sE-1.
At the distance of 500 pc, the derived ambient density is 0.2 cmE-3
and the x-ray radiating mass is < 0.1 solar mass, which suggests
that the remnant is comparably young (< or = 10E3 yr)."
SUPERNOVA 1995E IN NGC 2441
P. Garnavich, A. Riess, P. Challis, and R. Kirshner, Center
for Astrophysics, report that this object is highly reddened. A
spectrum obtained by P. Berlind on Feb. 24 UT with the 1.5-m
Tillinghast Telescope on Mt. Hopkins shows that SN 1995E has an
exceptionally red continuum for a normal type-Ia supernova near
maximum. In addition, a strong, narrow absorption feature due to
Na I is seen near the redshift of NGC 2441. The measured equivalent
width of 0.14 nm, combined with the continuum shape, suggests that
the visual extinction to SN 1995E could well exceed one magnitude.
NOTICE TO CONTRIBUTORS
A planned electrical shutdown means that the Central Bureau
will be unable to react quickly to electronic communications on
Mar. 4 (Saturday), possibly for the whole of the UT day. Incoming
messages will be stored for later attention, and it is probable
that the shutdown will not in fact affect the whole day.
Telephones will be manned for some of the downtime, so really
urgent information can be reported in this manner.
1995 March 2 (6142) Daniel W. E. Green
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