Central Bureau for Astronomical Telegrams
IAUC 3585: SN IN NGC 1532; X-RAY FLARE IN HD 27130; X-RAY SOURCES
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Circular No. 3585
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758
SUPERNOVA IN NGC 1532
R. Kirshner, Department of Astronomy, University of Michigan,
reports that Mar. 9 and 11 observations of the supernova in NGC
1532 by Kriss and Berg at McGraw-Hill Observatory show that this
object is a type-II supernova a few weeks past maximum light, as
judged by H-alpha emission and H-beta absorption; V was ~ 13.
X-RAY FLARE IN HD 27130
R. A. Stern and J. H. Underwood, Jet Propulsion Laboratory;
and S. K. Antiochos, Stanford University, guest observers with the
Einstein Observatory, write: "The 0.3-6.0-nm x-ray flux from the
Hyades binary system HD 27130 underwent a 40-fold increase to
10**24 J/s shortly before 1980 Sept. 20d06h13m UT. This flare decayed
with an e-foldlng time of ~ 2500 s. HD 27130 has been determined
recently to be a double-lined eclipsing binary with a period
of 5.6 days. The primary is a main-sequence G star, while the secondary
is probably a K dwarf (R. McClure, private communication).
Monitoring of this system for evidence of optical flaring or unusual
spectral characteristics would be valuable."
X-RAY SOURCES
J. B. Hutchings, A. P. Cowley and D. Crampton, Dominion Astrophysical
Observatory, write: "The following results were obtained
from observations made Feb. 27-Mar. 3 with the Cerro Tololo Interamerican
Observatory's 4-m telescope: 1) A 0538-66. Optical spectra
of this object (near phase 0.5 in its 16.7-day x-ray outburst
period) show that it is still in the continued shell phase (cf.
IAUC 3570). Velocities were: H-beta emission, +340 km/s; H-beta absorption,
-180 km/s; He II (468.6 nm) emission, +240 km/s with no absorption.
The star was at B ~ 14.7. 2) GX 339-4 (= 4U 1658-48). The optical
counterpart of this source (cf. Doxsey et al. 1979, Ap.J. Letters
228, L67) appears to be in a previously-unrecorded low state, the
magnitude being fainter than ~ 20. 3) V1223 Sgr (= 4U 1849-31).
This optically-pulsating (13.2-min period) source (cf. IAUC 3529)
shows Balmer emission narrow peaks which split and merge with a period
of ~ 26 min. He II 468.6 nm shows a single-peak profile. 4)
1E 0643.0-1648. This cataclysmic variable (IAUC 3529) has a spectroscopic
period of ~ 5.2 hr (K ~ 100 km/s) and appears to have an
orbital lightcurve with a large, variable amplitude (~ 0.5-1.0 mag)
1981 March 17 (3585) Daniel W. E. Green
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