Central Bureau for Astronomical Telegrams
IAUC 6260: AX J2315-592; R CrB
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 6261
.dvi or
.ps format.
Circular No. 6260
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
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)
Phone 617-495-7244/7440/7444 (for emergency use only)
AX J2315-592
K. Misaki, Y. Kamata, Y. Terashima, K. Isobe, H. Kunieda, and
Y. Tawara, Nagoya University; T. Tsuru, Y. Maeda, M. Sakano, M.
Akiyama, and H. Sogawa, Kyoto University; and M. Ishida and R.
Fujimoto, Institute of Space and Astronautical Science, communicate:
"ASCA discovered a new x-ray source during the observation of IRAS
23128-5919 carried out during Nov. 2.55-3.87 UT. The new source is
located at R.A. = 23h15m18s, Decl. = -59o10'.7 (equinox 2000.0;
error circle 1' radius). There are two optical stars (at 500 nm)
of mag 16-17 within this circle in the online chart of 'Sky View'
(provided by NASA). Unfortunately, the source was out of the
field-of-view of the SIS, and only the GIS data are available. The
average x-ray flux is 2.3 x 10E-11 erg cmE-2 sE-1, or 1.1 mCrab, at
2-10 keV. No x-ray source with this intensity is known in the
HEAO-1 catalogue, GINGA archival data, ROSAT WFC catalogue, or
SIMBAD. The new source AX J2315-592 shows a strong periodic x-ray
modulation with period 5360 +/- 100 s (or 1.49 +/- 0.03 hr). The
lightcurve is characterized by a deep and narrow intensity minimum,
which lasts for 20 percent of the period. The deficit of the
countrate is approximately 90 and 70 percent of the peak intensity
in the energy ranges 0.7-2.4 and 2.4-10 keV, respectively. The
average spectrum is hard and is represented either by a power law
with photon index between 1.3 and 1.4 or by thermal bremsstrahlung
with a temperature of > 20 keV. The absorption is small and the
line-of-sight hydrogen column density is < 1 x 10E21 cmE-2. A
prominent iron emission line is detected at 6.79 +/- 0.06 keV with
an equivalent width of about 1000 eV. The line is broad with 1-
sigma width of 200-400 eV, suggestive of a blend of thermal and
fluorescent emissions. From the lightcurve and spectral
characteristics, AX J2315-592 is probably a new AM Her-type
cataclysmic variable. Follow-up optical observations (spectroscopy
and polarimetry) are encouraged."
R CORONAE BOREALIS
Visual magnitude estimates (cf. IAUC 6245): Oct. 19.14 UT,
10.6 (C. Spratt, Victoria, BC); 20.72, 11.5 (L. Szentasko,
Veresegyhaz, Hungary); 23.783, 11.8 (P. Schmeer, Bischmisheim,
Germany); 26.74, 11.9 (M. V. Zanotta, Laino, Italy); 31.74, 12.9
(Zanotta); Nov. 2.75, 12.1 (Szentasko); 5.74, 13.3 (Zanotta); 9.72,
13.2 (A. Mizser, Budapest, Hungary).
1995 November 11 (6260) Daniel W. E. Green
Read IAUC 6261
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
