Central Bureau for Astronomical Telegrams
IAUC 7081: N Mus 1998; MXB 1730-335; RX J0052.1-7319
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 7082
.dvi or
.ps format.
Circular No. 7081
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7244/7440/7444 (for emergency use only)
NOVA MUSCAE 1998
S. J. O'Meara, Volcano, HI, reports that prediscovery images
of this nova at mpg about 8.0 appear on three successive
photographs taken with Fuji Sensia 400 color slide film beginning
at 1998 Dec. 27.60 UT. The about 10-min exposures were taken with
a guided 35-mm camera (+ 50-mm lens).
Corrigendum. On IAUC 7079, line 7, for Dec. 1.1754 read
Dec. 31.1754
MXB 1730-335
D. W. Fox and W. H. G. Lewin, Massachusetts Institute of
Technology, report on behalf of a collaboration: "We have performed
a timing analysis of the first second of data from each of 31
type-I x-ray bursts from the rapid burster observed from Nov. 1996
to Feb. 1998 with the Rossi X-ray Timing Explorer (energy range
5.5-16 keV only). We find a statistically significant pair of
peaks in the summed power-density spectrum, with peak centroid
frequencies of 154.9 +/- 0.1 and 306.6 +/- 0.1 Hz, respectively.
We suggest that this finding indicates a neutron-star spin period
of 6.5 ms for the rapid burster."
RX J0052.1-7319
R. C. Lamb and T. A. Prince, California Institute of
Technology; D. J. Macomb, Goddard Space Flight Center, NASA; and
M. H. Finger, Marshall Space Flight Center, NASA, report their
discovery of 15.3-s pulsations from the variable x-ray source RX
J0052.1-7319 (1E 0050.3-7335) from analysis of 1996 data: "The
pulsations are observed in both ROSAT HRI observations (0.1-2 keV)
that span the interval 1996 Nov. 10.71-Dec. 9.16 UT and
contemporaneous BATSE observations (20-50 keV). During this
outburst, the neutron star assumed to be responsible for the
pulsations is observed to be spinning up on a timescale of 38 yr
with a frequency time derivative of 5.4 x 10E-11 Hz/s. Significant
power is seen in the fundamental, as well as in the second and
third harmonics. The pulsed fraction in the HRI is 0.27(2). The
counting rate, 0.7 counts/s, corresponds to a preliminary flux
value of 2.6 x 10E-11 erg sE-1 cmE-2 and a luminosity (0.1-2 keV)
at an assumed distance of 60 kpc (appropriate for the SMC) of 1.1 x
10E37 erg/s. The position of the source (Kahabka and Pietsch 1996,
A.Ap. 312, 919) is R.A. = 0h52m11s.3, Decl. = -73o19'13" (equinox
2000.0). No optical counterpart for the source is yet reported."
(C) Copyright 1999 CBAT
1999 January 8 (7081) Daniel W. E. Green
Read IAUC 7082
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
