Central Bureau for Astronomical Telegrams
IAUC 7363: N Sgr 2000; XTE J1543-568; SAX J1808.4-3658
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Circular No. 7363
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 SAGITTARII 2000
R. M. Wagner and R. Bertram, Ohio State University; and S. G.
Starrfield, Arizona State University, report: "On Feb. 11.55 UT, we
obtained a spectrum (range 395-600 nm, resolution 1.3 nm) with the
2.4-m Hiltner Telescope of the MDM Observatory on Kitt Peak of the
possible nova reported on IAUC 7362. The spectrum exhibits broad
emission lines from the Balmer series of hydrogen and Fe II
superposed on a red continuum. The H-beta and H-gamma emission
lines exhibit P-Cyg profiles. The instrument-corrected FWHM of
H-beta emission is 1530 km/s, implying an expansion velocity of 765
km/s. The equivalent width of H-beta emission is 16 nm. The
spectrum is typical of classical novae in the early decline phase.
Additional observations are encouraged."
XTE J1543-568
F. E. Marshall, Goddard Space Flight Center (GSFC); T.
Takeshima, GSFC and Universities Space Research Association; and J.
in 't Zand, Space Research Organization Netherlands, report the
discovery of a transient, pulsating x-ray source designated XTE
J1543-568: "The source was first seen in a slew of the
Proportional Counter Array on the Rossi X-ray Timing Explorer at
Feb. 6.84 UT with a 2-10-keV flux of 2 x 10**-10 erg cm**-2 s**-1.
A subsequent observation with the PCA on Feb. 10.69 found a similar
intensity and located the source in an error box that corresponds
to galactic coordinates l = 324.88 +/- 0.2 deg, b = -1.45 +/- 0.1
deg, centered on R.A. = 15h43m33s, Decl. = -56o48'.0 (equinox
2000.0). The flux is strongly modulated with a period of 27.12 +/-
0.02 s. Observations at other wavelengths are encouraged."
SAX J1808.4-3658
S. Wachter and D. W. Hoard, Cerro Tololo Interamerican
Observatory (CTIO), report: "We observed the optical counterpart
(Giles et al. 1999, MNRAS 304, 47) of the x-ray transient and
millisecond pulsar SAX J1808.4-3658 that was recently reported to
exhibit renewed x-ray activity (IAUC 7358). On Feb. 9.38 UT, using
the CTIO 0.9-m telescope (+ 2K CCD), we measured I = 18.2 +/- 0.1
relative to the local standards given by Giles et al. (ibid.).
This indicates that the counterpart has not reached the brightness
levels (I = 15.6, IAUC 6885) observed during the previous outburst
in 1998 (IAUC 6876)."
(C) Copyright 2000 CBAT
2000 February 11 (7363) Daniel W. E. Green
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