Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 5714: X-RAY PULSAR IN N63A; P/SCHWASSMANN-WACHMANN 1

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 5713 SEARCH Read IAUC 5715

View IAUC 5714 in .dvi or .ps format.
IAUC number 

                                                  Circular No. 5714
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)


X-RAY PULSAR IN N63A
     K. Dennerl and M. Kurster, Max-Planck-Institut fur Extraterrestrische
Physik, Garching, communicate:  "We report the discovery
of pulsed x-ray emission with a barycentric period of 201.0 s from
the direction of the supernova remnant (SNR) N63A in the Large
Magellanic Cloud (cf. Henize 1956, Ap.J. Suppl. 2, 315) with the
ROSAT satellite during a 45 000-s Position Sensitive Proportional
Counter (PSPC) observation.  Since N63A was located at an off-axis
angle of 31', the spacecraft wobble can be excluded as a source of
artificial variability.  The pulse profile shows a highly significant
modulation consisting of two broad peaks of similar intensity
and shape separated by about 0.45 in phase.  Due to the degraded
Point Spread Function, the observed flux contains contributions
from the diffuse x-ray emission of the SNR.  The total count rate
for the unresolved source region (SNR and pulsar) is modulated
between 7.2 and 7.8 cts/s in the band 0.1-2.4 keV, corrected for
vignetting. The peak-to-valley ratio of the modulation is increased
from 1.1 to 1.5 by a spectral selection of the band 0.7-1.1 keV and
a rough spatial selection of the pulsar region based on the pulsed
image.  The pulsed emission can be described by a blackbody spectrum
with a temperature of 0.15 keV.  This implies a luminosity of
the pulsed flux of 5 x 10E35 erg/s in the total PSPC energy range
if the pulsar is located in the LMC.  We have also found this pulsar
in the ROSAT all-sky survey data.  Further analysis is in
progress."


PERIODIC COMET SCHWASSMANN-WACHMANN 1
     The observations by A. Nakamura reported on IAUC 5704 were
made with a CCD.  Further total magnitude estimates (cf. IAUC 5708):
Feb. 10.14 UT, 12.7 (A. Hale, Las Cruces, NM, 0.41-m reflector;
visual); 12.53, 12.5 (T. Kojima, Chiyoda, Gunma-ken, Japan, 0.25-m
f/3.4 Wright-Schmidt camera + TP 6415 film); 14.53, 12.6 (A.
Nakamura, Kuma, Japan, 0.20-m reflector; visual); 15.93, 12.7 (J.-C.
Merlin, Le Creusot, France, 0.40-m reflector; T-Max 400 film +
image intensifier); 16.74, 12.8 (H. Mikuz, Ljubljana, Slovenia,
0.20-m f/2 Baker-Schmidt camera + V filter + CCD); 18.29, 12.8
(Hale); 20.21, 12.5 (I. Ferrin and F. Fuenmayor, Merida, Venezuela,
1-m Schmidt telescope + red-sensitive CCD); 20.78, 13.4 (Mikuz).


1993 February 25               (5714)            Daniel W. E. Green

Read IAUC 5713 SEARCH Read IAUC 5715

View IAUC 5714 in .dvi or .ps format.

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

Valid HTML 4.01!