Central Bureau for Astronomical Telegrams
IAUC 5429: 1992A; PSR 1509-58
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Circular No. 5429
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
SUPERNOVA 1992A IN NGC 1380
N. Suntzeff, Cerro Tololo Interamerican Observatory, reports:
"K. Ross has obtained a spectrogram (range 480-650 nm) of SN 1992A
on Jan. 12.2 UT with the CTIO 4-m telescope. This object has
spectral features very similar to a type-Ia supernova near or before
maximum light, such as SN 1986G in NGC 5128 (Phillips et al. 1987,
PASP 99, 592). The blue continuum and lack of interstellar sodium D
absorption indicate a rather low reddening for this object."
M. Della Valle, European Southern Observatory, communicates: "A
CCD spectrogram (range 400-800 nm, resolution about 2 nm) of SN
1992A was obtained on Jan. 13.95 UT with the New Technology Telescope
(+ EMMI) at La Silla. The spectrum shows the deep absorption
of Si II (635.5 nm), indicating a type-Ia supernova. Other absorptions
are observed at 578, 548, 530 (Si II), and 429 nm (Mg II). A
preliminary measurement of the expansion velocity deduced from the
minimum of the Si II 635-nm absorption yields about 13 000 km/s.
The spectrum resembles that of SN 1989B (Barbon et al. 1990, A.Ap.
237, 79) 2-3 days before maximum."
PSR 1509-58
R. B. Wilson, M. H. Finger, G. J. Fishman, C. A. Meegan, and W.
S. Paciesas report for the Compton Gamma Ray Observatory BATSE team:
"The 150-ms x-ray/radio pulsar PSR 1509-58 (the Circinus Pulsar) in
the supernova remnant MSH 15-52 has been detected in the low-energy
gamma-ray region. It is only the second pulsar to be seen at these
energies (the other being the Crab Pulsar). Pulsed emission is
clearly seen in the energy range from 20 keV to > 2 MeV. In this
region, the spectrum is harder than that of the Crab Pulsar. The
pulse profile is similar in shape and duty cycle to that seen in the
x-ray region (Trussoni et al. 1990, A.Ap. 234, 403; Kawai et al.
1991, Ap.J. 383, L65), although the single pulse becomes narrower at
higher energies. Observations were made with the large-area BATSE
detectors on the Compton Observatory. The results below are from an
observation during 1991 December, with a 'live-time' of 1.88 days.
(The source was also observed in 1991 November. Observations are
continuing; ground-based observations are encouraged.) The approximate
pulsed fluxes in various energy bands, relative to the Crab
pulsed flux, are: 20-72 keV, 0.028 +/- 0.004; 72-120 keV, 0.031 +/-
0.006; 120-235 keV, 0.061 +/- 0.008; 235-740 keV, 0.109 +/- 0.029."
1992 January 14 (5429) Daniel W. E. Green
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