Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 5860: 1993X; GRO J0422+32; 1993a

The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).

Read IAUC 5859 SEARCH Read IAUC 5861

View IAUC 5860 in .dvi or .ps format.
IAUC number 

                                                  Circular No. 5860
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 1993X IN NGC 2276
     A. V. Filippenko and T. Matheson, University of California at
Berkeley, report:  "CCD spectrograms (range 310-990 nm, resolution
0.7 nm) obtained on Sept. 10 UT with the Shane 3-m reflector at
Lick Observatory reveal that SN 1993X (cf. IAUC 5850, 5853) is of
type II.  The spectrum is somewhat peculiar, however, being dominated
by a broad H-alpha emission line with little or no P-Cyg absorption.
A much narrower, but slightly resolved, H-alpha emission
line is also present.  These characteristics resemble those of
supernovae whose ejecta experience considerable interaction with
circumstellar gas.  Observations at radio wavelengths would be
worthwhile. The recession velocity of the parent galaxy is about 2400
km/s."


GRO J0422+32
     P. Zhao, P. Callanan, M. Garcia, and J. McClintock, Smithsonian
Astrophysical Observatory, write:  "CCD photometry obtained at
the F. L. Whipple Observatory 1.2-m telescope gives the following R
magnitudes:  Sept. 8.37 UT, 18.1 +/- 0.5; 9.48, 17.7 +/- 0.2.
Thus, GRO J0422+32 has dimmed by about 2-3 mag since its unexpected
brightening on Aug. 10-16 (cf. IAUC 5842, 5844).  This may help
explain the faintness of the x-ray source observed on Aug. 26 UT
(IAUC 5851).  Since the optical counterpart's rapid decline in Mar.-
Apr., we have obtained photometry on 16 nights during Apr. 13-28 (V,
R), July 18-29 (R), and Sept. 8-9 (R); all these low-state data are
consistent with V = 17.6 +/- 0.3 and R = 17.8 +/- 0.3.  We have
monitored V and R on 58 nights since 1992 Nov. 18."
     Filippenko and Matheson also report that GRO J0422+32 has faded
very rapidly since its second outburst in August.  Rough estimates
made on Sept. 11 UT with the Shane 3-m reflector yield V = 18.9 +/-
0.5, as compared with V = 15.3 +/- 0.1 on Aug. 24 (IAUC 5851).  The
spectrum (range 310-800 nm), although noisy, is reasonably featureless
except for prominent, double-peaked hydrogen Balmer emission
lines and weaker helium lines.


COMET MUELLER (1993a)
     Total visual magnitude estimates (cf. IAUC 5838):  Aug. 18.99
UT, 11.6 (B. H. Granslo, Fjellhamar, Norway, 0.20-m reflector);
21.45, 11.7 (A. Hale, Orogrande, NM, 0.20-m reflector); 29.19, 10.7
(A. Pereira, Cabo da Roca, Portugal, 0.15-m reflector); Sept. 11.08,
11.0 (Granslo).


1993 September 11              (5860)            Daniel W. E. Green

Read IAUC 5859 SEARCH Read IAUC 5861

View IAUC 5860 in .dvi or .ps format.

Our Web policy. Index to the CBAT/MPC/ICQ pages.

Valid HTML 4.01!