Central Bureau for Astronomical Telegrams
IAUC 3362: NOVALIKE OBJECT IN Cen; JUPITER
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 3363
Circular No. 3362
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
NOVALIKE OBJECT IN CENTAURUS
L. Kaluzienski and S. Holt, Goddard Space Flight Center, report
that continued monitoring of the x-ray nova in Centaurus (IAUC
3360) with the Ariel 5 all-sky monitor has yielded the following
improved position for the source: R.A. = 14h53m, Decl. = -32o.8 (90-percent
confidence error +/- 0o.8; equinox 1950.0); this is consistent with
its initial identification with Cen X-4. The source brightened
from a level of ~ 1.4 times the Crab Nebula (3-6 keV) on May 14 to
a peak value of ~ 4 times the Crab on May 17 and has remained at
roughly this level through May 20.
C. Canizares and J. McClintock, Massachusetts Institute of
Technology; and J. Grindlay, Center for Astrophysics, report the
discovery of what is presumably the optical counterpart of the
above. The observations were carried out at the Cerro Tololo
Interamerican Observatory. Inspection of a plate of the region obtained
by M. Liller with the 400-cm telescope on May 19 revealed a
star at R.A. = 14h55m19s.5, Decl. = -31o28'07" (+/- 5"; equinox 1950.0) that
had brightened to ~ magnitude 13 from ~ magnitude 19 on the Palomar
Sky Survey. Photoelectric photometry with the 150-cm telescope on
May 20.15 UT gave mean values of V = 12.9, B-V = 0.0 +/- 0.1, U-B =
-0.8 +/- 0.2. The B magnitude showed intrinsic variations over ~ 5
percent over ~ 1 hr. By May 21.20 the star had faded by ~ 0.5
magnitude in all colors. Two spectrograms obtained by L. Stryker with
the 100-cm telescope show a nearly featureless continuum, possibly
with very faint emission at He II 4686 A and H-alpha. The star is 0o.24
from the revised Vela-satellite x-ray position of Cen X-4, which
has a quoted uncertainty of +/- 0o.2. The remarkable similarity to
the x-ray transient A0620-00 = V616 Mon leaves little doubt that
the star is the optical counterpart of Cen X-4. For reference the
star is flanked by two ~ magnitude 14 stars 25" northeast and 40"
southwest, respectively.
JUPITER
P. Mackal, Association of Lunar and Planetary Observers, reports
the detection by P. Budine, P. McIntosh and D. C. Parker of a
disturbance on Jupiter's South Equatorial Belt. At discovery, Mar.
11, its system II longitude was 141o. Four spots indicate a fast-current
rotation period of 9h54m42s, one spot a slow-current period
of 9h57m38s, based on observations through early April.
1979 May 23 (3362) Brian G. Marsden
Read IAUC 3363
Our Web policy. Index to the CBAT/MPC/ICQ pages.
