Central Bureau for Astronomical Telegrams
IAUC 5447: N Pup 1991; 1991bg, 1992B
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Circular No. 5447
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
NOVA PUPPIS 1991
S. N. Shore, Goddard High Resolution Spectrometer team and
Computer Sciences Corporation; G. Sonneborn, Goddard Space Flight
Center, NASA; R. Gonzalez-Riestra, International Ultraviolet Explorer
(IUE) Observatory, Vilspa; S. G. Starrfield, Arizona State University;
and J. Krautter, Landessternwarte Heidelberg, report: "Further
observations with the IUE satellite show that Nova Pup 1991 remains
in an optically thick shell phase (cf. IAUC 5428). The Mg II 280-nm
emission line flux has steadily decreased, and there have been no
substantial changes in the line profile since the first observation
on Jan. 7. The continuum windows in the shell spectrum (120-260 nm)
are growing stronger and narrower as the optical depth decreases.
The integrated ultraviolet flux shortward of 200 nm has peaked with
time, while that longward of 200 nm has steadily decreased, as shown
by the following flux measurements given in units of 10E-10 erg
cmE-2 sE-1 for bands 120-200 and 200-335 nm, respectively: Jan. 7.1
UT, 1.59, 10.1; Jan. 10.0, 1.97, 10.8; Jan. 21.7, 2.81, 8.02; Jan.
29.1, 3.02, 4.17; Jan. 31.8, 2.89, 3.91; Feb. 6.1, 2.53, -. The
peak in the short-wavelength flux (120-200 nm) occurred on Jan.
27.5, approximately one month after optical outburst. From our
previous experience with other CO novae, we expected the shell to have
become optically thin by this time. Thus, all indications now point
to Nova Pup 1991 being a slow nova, perhaps like Nova LMC 1988 No.
1, and possibly one of the most massive and slowest shells yet
observed. We are continuing to monitor this nova with IUE.
Contemporaneous optical spectroscopy for ejecta velocities and infrared
photometry for angular radii would be very beneficial."
Visual magnitude estimates (cf. IAUC 5437): Jan. 27.03 UT, 9.6
(A. Pereira, Cabo da Roca, Portugal); 28.54, 9.6 (A. Pearce, Scarborough,
W. Australia); 30.55, 9.7 (Pearce); 31.95, 10.0 (P. Schmeer,
Bischmisheim, Germany); Feb. 6.01, 10.0 (Pereira).
SUPERNOVAE 1991bg AND 1992B
C. Pollas, Observatoire de la Cote d'Azur, reports photographic
magnitudes for two supernovae. SN 1991bg in NGC 4374 was at B about
17.5 on Feb. 1.2 and 2.2 UT. SN 1992B in an anonymous galaxy (cf.
IAUC 5437) was at mag about 20 on Tech Pan exposures taken Feb. 2.1
and 6.2.
1992 February 10 (5447) Daniel W. E. Green
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