Central Bureau for Astronomical Telegrams
IAUC 8144: XTE J1814-338; 2003ed
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Circular No. 8144
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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XTE J1814-338
C. B. Markwardt, University of Maryland and Goddard Space
Flight Center (GSFC); and J. H. Swank, GSFC, report that RXTE PCA
monitoring observations of the Galactic-center region have revealed
a new millisecond pulsar, designated XTE J1814-338. PCA cross
scans on June 5.1 UT determined the position to be R.A. = 18h13m.7,
Decl. = -33o46' (equinox 2000.0), with a 99-percent confidence
radius of 2'. The observation also contained pointed data, during
which coherent pulsations were detected at a barycentered frequency
of 314.319 Hz, making this the fifth known millisecond accreting
pulsar. There appears to be a significant sinusoidal modulation of
the pulse frequency, at a period of 1.9 +/- 0.3 hr, with a half-
amplitude of 0.014 +/- 0.002 Hz, although the short time baseline
(3400 s) may contribute significant systematic uncertainties.
Interpreted as an orbital Doppler modulation, the orbital period is
most similar to the first such pulsar, SAX J1808.4-3658 (IAUC 6876,
6877). The following 2-10-keV x-ray fluxes (in mCrab, with
uncertainties of approximately 0.1 mCrab) indicate that the source
intensity is still increasing: May 27.5, 0.1; 31.5, 1.8; June 3.5,
7.1; 5.1, 10.5. Observations at other wavelengths are encouraged.
SUPERNOVA 2003ed IN NGC 5303A
D. C. Leonard, University of Massachusetts, Amherst; and R.
Chornock and A. V. Filippenko, University of California, Berkeley,
report that inspection of CCD spectra (range 300-930 nm) of the
type-II SN 2003ed (IAUC 8129), obtained on May 25 UT with the Keck-
I telescope, show it to bear a striking resemblance to the spectrum
of the type-IIb SN 1993J, about 32 days past explosion (Matheson et
al. 2000, A.J. 120, 1487). In addition to features typically seen
in type-II supernovae at this stage, lines of He I with P-Cyg
profiles have emerged, suggesting that the progenitor of SN 2003ed
lost a substantial fraction of its hydrogen envelope prior to
exploding. In addition, spectropolarimetry (range 570-940 nm)
shows an average continuum polarization of about 1 percent, with
strong modulations across the H_alpha and Ca II-infrared-triplet
features of up to about 1 percent in the individual Stokes
parameters. While some of the continuum polarization may be due to
interstellar dust, the changes across the line features suggest
substantial polarization due to scattering by aspherical supernova
ejecta, as has been inferred for SN 1993J at a similar epoch (Tran
et al. 1997, PASP 109, 489).
(C) Copyright 2003 CBAT
2003 June 6 (8144) Daniel W. E. Green
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