Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 7300: XTE J1739-285; 1999ek; 1999em; C/1999 S4

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 7299  SEARCH Read IAUC 7301

View IAUC 7300 in .dvi or .ps format.
IAUC number


                                                  Circular No. 7300
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)


XTE J1739-285
     C. B. Markwardt, University of Maryland and Goddard Space
Flight Center (GSFC); F. E. Marshall and J. H. Swank, GSFC; and Wei
Cui, Massachusetts Institute of Technology, write:  "RXTE PCA scans
of the galactic-center region on Oct. 19.4 UT revealed a transient
x-ray source, designated XTE J1739-285.  The best-fitting position
for the source is R.A. = 17h39m.9, Decl. = -28o29' (equinox 2000.0;
estimated uncertainty about 5', due primarily to nearby
contaminating sources in the collimator field-of-view).
Approximate x-ray fluxes (with uncertainties of < 2 percent)
derived from PCA scans, in units of mCrab in the band 2-10 keV:
Oct. 19.4, 77; 21.2, 66; 24.4, 170; 27.1, 200; 30.2, 157.  The
source is distinct from known persistent x-ray sources SLX 1737-282
and GRS 1734-292.  A pointed PCA exposure of 1400 s on Oct. 29.6
revealed no detectable quasiperiodic oscillations or high-frequency
variability.  Follow-up observations by imaging instruments are
encouraged."


SUPERNOVA 1999ek IN UGC 3329
     S. Jha, P. Challis, P. Garnavich, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum,
obtained by M. Calkins with the F. L. Whipple Observatory 1.5-m
telescope (+ FAST spectrograph) on Oct. 30.46 UT, shows SN 1999ek
to be a type-Ia supernova near maximum light.  Adopting the NED
recession velocity for UGC 3329 of 5253 km/s yields an expansion
velocity for Si II (rest 635.5 nm) of 9800 km/s.  The estimated age
of the supernova from the spectral features as above is 1.2 +/- 3
days after maximum light.


SUPERNOVA 1999em IN NGC 1637
     CCD magnitude by D. Hanzl, Brno, Czech Republic:  Nov. 1.033
UT, V = 14.32 +/- 0.03.


COMET C/1999 S4 (LINEAR)
     Total visual magnitude estimates:  Oct. 31.79 UT, 14.6 (K.
Hornoch, Lelekovice, Czech Republic, 0.35-m reflector); Nov. 2.32,
14.1 (A. Hale, Cloudcroft, NM, 0.41-m reflector).

                      (C) Copyright 1999 CBAT
1999 November 3                (7300)            Daniel W. E. Green

Read IAUC 7299  SEARCH Read IAUC 7301

View IAUC 7300 in .dvi or .ps format.


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


Valid HTML 4.01!