Central Bureau for Astronomical Telegrams
IAUC 7023: NOVAE IN M31; SGR 1900+14, PSR J1907+09
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Circular No. 7023
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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NOVAE IN M31
M. Papenkova, J. Y. King, E. Halderson, T. Shefler, M. Modjaz,
W. D. Li, R. R. Treffers, and A. V. Filippenko, University of
California at Berkeley, report their discovery of an apparent nova
in M31 (NGC 224) during the course of the Lick Observatory
Supernova Search with the 0.8-m Katzman Automatic Imaging Telescope
(KAIT). The nova was found and confirmed on unfiltered CCD images
taken on Sept. 30.3 (mag about 16.1) and Oct. 1.3 UT (mag about
16.2). The object is located at R.A. = 0h42m49s.9, Decl. =
+41o16'48" (equinox 2000.0; due to a lack of nearby stars, this
semiaccurate position was calculated as an offset from the NED
position for the nucleus of M31), which is about 63" east and 39"
north of the galaxy nucleus. A KAIT image of M31 taken on July
23.5 shows nothing at the position of the nova (limiting mag about
19.0). The nova reported on IAUC 7015 is also present on Sept.
30.3 and Oct. 1.3 KAIT frames at unfiltered mag about 18.5.
SGR 1900+14 AND PSR J1907+09
K. Xilouris, National Radio Astronomy and Ionospheric Center;
C. Kouveliotou, Universities Space Research Association at Marshall
Space Flight Center, NASA; D. R. Lorimer, Max Planck Institute for
Radio Astronomy, Bonn; R. Ramachandran, University of Amsterdam
(UoA); and J. van Paradijs, UoA and University of Alabama in
Huntsville, report: "We observed the soft-gamma-ray repeater SGR
1900+14 during June with the Arecibo telescope. A search for
pulsed radio emission at 1.4 GHz did not detect the 5.16-s period
reported for SGR 1900+14 (IAUC 7001). We have discovered, however,
a 226-ms radio pulsar, PSR J1907+09. The nominal position of the
pulsar is R.A. = 19h07m21s.1, Decl. = +9o18'41" (equinox 2000.0),
with an uncertainty of about 2'. This is the first pulsar to be
discovered with the recently upgraded Arecibo telescope.
Confirmation observations at 1.4 GHz were made with the Effelsberg
100-m telescope several times during September. Measurements of
the pulse period over a 112-day baseline give a period derivative
of (1 +/- 2) x 10E-13 s/s (3-sigma upper limit). The initial
estimate for the dispersion measure of 350 +/- 10 pc cmE-3 places
the pulsar at a distance of about 7000 pc. The mean flux density
at 1.4 GHz is about 0.3 mJy. Despite a number of observations
with the Arecibo telescope at 430 MHz, the pulsar was so far not
detected at this frequency, suggesting that the degree of
interstellar scattering along this line-of-sight is large. We
encourage further observations of the source."
(C) Copyright 1998 CBAT
1998 October 5 (7023) Daniel W. E. Green
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