Central Bureau for Astronomical Telegrams
IAUC 5692: 1992bm; GRO J0422+32; P/SCHWASSMANN-WACHMANN 1
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Circular No. 5692
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@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
SUPERNOVA 1992bm IN ANONYMOUS GALAXY
M. Turatto, E. Cappellaro, and S. Benetti communicate: "We
have obtained a noisy spectrum of SN 1992bm (cf. IAUC 5672) on Jan.
15 with the Boller & Chivens spectrograph (+ CCD) at the 1.82-m
reflector of the Asiago Observatory. The only clear feature is a
broad (FWHM about 8.0 nm) emission at 691 nm that we identify with
H-alpha (z about 0.05). This suggests that the object is probably
a type-II supernova about 2 months after maximum."
GRO J0422+32
C. Chevalier and S. A. Ilovaisky, Observatoire de Haute-
Provence, write: "New CCD photometry of the optical counterpart of
this x-ray transient has been obtained with the Haute-Provence 1.2-
m telescope on Jan. 3/4, 4/5, 14/15, 15/16, and 18/19. Analysis of
these data shows a very clear modulation with a period of 5.098 +/-
0.005 hr and a full amplitude of 0.15 magnitude (in V). The
modulation may have twice this period if the light curve is double-
waved. This new period differs significantly from that reported by
Kato et al. (IAUC 5676), which is incompatible with our data. The
object is now 0.8 mag fainter (in V) than in early 1992 September,
and substantially brighter than expected from the decline rate of
0.01 mag/day derived in the first months following the outburst
(IAUC 5644, 5650). This means that the optical decay curve probably
also displayed a secondary maximum in 1992 December as reported
in hard x-rays by the BATSE team (IAUC 5685). Observations are
continuing at Haute-Provence."
PERIODIC COMET SCHWASSMANN-WACHMANN 1
J. Luu, University of California at Berkeley; and D. Jewitt,
University of Hawaii (UH), report: "High-resolution images reveal
cyclic photometric variations that are confined to the central 1"
of the coma. The observations were taken at the UH 2.2-m telescope
in subarcsecond seeing on 1991 Nov. 17 and 1992 Nov. 27 UT. The
best-fit lightcurve periods are near 10 +/- 1 hr, while the range
of variation is about 0.5 mag. The absence of lagged variations in
the near-nucleus coma suggests that the central variations are due
to nucleus rotation at the stated period, rather than to coma
activity. The period is short compared to the about 5-day period
previously estimated from coma morphological studies, but is similar
to the rotation periods measured by the same technique in other
short-period comets."
1993 January 19 (5692) Daniel W. E. Green
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