THE ASTRONOMER Electronic Circular No 381 1990 Jan 24 22.01UT
Microlink:MAG60138 JANET:GMH at UK.AC.RO-GREENWICH.STARLINK
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke,
Hants, RG22 4PP, England. Telephone: (0256)471074 Int:+44256471074
Telex: 94082518 Answerback: TAGUY
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SUPERNOVA 1990B IN NGC 4568
On behalf of the Berkeley Automated Supernova Search,
S. Perlmutter and C. Pennypacker report the discovery of a mag 16
supernova in NGC 4568 (R.A. 12h34m02s, Decl. +11d30'.9, 1950.0),
in five images obtained during Jan. 20.47 and 21.47-21.51 UT.
The supernova is 6" W and 10" N of the galaxy's nucleus and was
not present to limiting magnitude 18 (95-percent confidence limit)
on 1989 Dec. 23. NGC 4568 should not be confused with NGC 4567,
which is 23" to the west and 66" to the north. IAUC 4949
COMET WILD (1990a)
Paul Wild, Astronomical Institute, Berne University, reports his
discovery of a comet at the following positions measured by
U. Hugentobler:
1990 UT R.A. (1950) Decl. m1
Jan. 21.98333 9 34 31.69 +20 39 39.5 13.5-14.0
22.89236 9 33 56.70 +20 43 03.4
The object is strongly condensed, with a fanshaped tail extending
about 1' to the northwest. IAUC 4950
SUPERNOVA 1990C IN ANONYMOUS GALAXY
C. Pollas, Observatoire de la Cote d'Azur, reports his discovery
of a possible faint supernova in a faint possibly interacting
system or S0 galaxy with a jetlike protrusion. The supernova, of
mag 19.5 on an unfiltered IIIa-J plate obtained on Jan. 20.97 UT,
is located at R.A. = 8h01m26s.02, Decl. = +22d52'25".8 (equinox
1950.0), 0".2 west and 1".9 north of the compact image of the
galaxy. The position of the central part of the elongated
component of the system (which is blue on the Palomar Sky Survey
prints) has end figures 25s.32, 26".4, and there is a red star
of mag 18 at end figures 25s.25, 16".9. A red plate
obtained on Jan. 23.0 confirms the object at R about 19.
IAUC 4950
NOVA IN NGC 1313
M. A. Dopita and S. D. Ryder, Mount Stromlo and Siding Spring
Observatories, report: "A nova has been discovered in the outer
parts of NGC 1313 at R.A. = 3h17m02s.6, Decl. = -66d43'57"
(equinox 1950.0). It appears to be well into its nebular phase,
was only weakly visible on a V-band CCD image taken on
1989 Dec. 28.48 UT but appeared bright on an H alpha CCD image
taken on Dec. 26.47 UT. A spectrum was obtained on
1990 Jan. 23.55 UT using the Double Beam Spectrograph on
the 2.3-m telescope at Siding Spring. This shows a very weak
blue continuum, with the Balmer lines strongly in emission,
He II 468.6 nm being at about 10 percent the intensity of
H beta. [Ne III], [O III] and [N II] are also seen. The ratio
of the 436.3-nm line to the 500.7-nm line of [O III] is about
1:3, indicating an electron density of 3-10 x 10**6 cm-3.
The H alpha line has a flux of about 10**-13 erg cm-2 s-1 and
is 750 km/s wide FWZM."
IAUC 4950
Guy M Hurst