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IAUC 7030: 1998ed; 1998ee; PSR 1937+21; C/1998 M5

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                                                 Circular No. 7030
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://cfa-www.harvard.edu/iau/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)

     J. Mueller reports her discovery of an apparent supernova (mag
about 18) on a plate taken on Sept. 16 with the 1.2-m Oschin
Schmidt Telescope by K. Rykoski in the course of the Palomar Outer
Solar System Ecliptic Survey.  SN 1998ed is located at R.A. =
23h00m14s.64, Decl. = -13o13'58".2 (equinox 2000.0), which is 6"
west and 2".7 south of the center of the host galaxy.  The new
object is also visible on plates taken on Sept. 14 and 15 UT.
There is no object at this position on the Digital Sky Survey.

     J. Maza, Department of Astronomy, University of Chile, reports
the discovery by Marina Wischnjewsky, on a T-Max 400 film taken by
L. E. Gonzalez using the Maksutov telescope at Cerro El Roble on
Oct. 14.255 UT, of a supernova (B about 17.5) located at R.A. =
1h53m31s.33, Decl. = -53o58'19".5 (equinox 2000.0), which is 5".1
east and 1".9 north of the nucleus of the host spiral galaxy.  The
object was confirmed via B and V direct images taken by D. Gonzalez
on Oct. 16.46 using the YALO telescope at Cerro Tololo.  SN 1998ee
is not visible on films obtained with the Cerro El Roble telescope
on Sept. 27.245 through clouds (B > 17) and on Sept. 15.256 (B > 19).

PSR 1937+21
     M. Takahashi and S. Shibata, Yamagata University; K. Torii,
National Space Development Agency of Japan; Y. Saito, Institute of
Space and Astronautical Science; and N. Kawai, Institute of
Physical and Chemical Research, report:  "The x-ray counterpart to
the fastest millisecond pulsar PSR 1937+21 was detected with ASCA
on 1997 Dec. 16.0-17.1 UT, setting a strong constraint on the
emission model for the pulsar radiation.  The x-ray source pulsed
at the same period as found in the radio bands, and had a hard
spectrum consistent with a power law with photon index 0.9 and flux
5.9 x 10E-13 erg cmE-2 sE-1 (2-10 keV).  Most of the x-ray flux
(50-90 percent in the band 1.7-6.5 keV) was contained in the narrow
primary peak with width probably < 130 microseconds, and with an
indication of an interpulse."

     Visual m_1 estimates by R. Bouma, Groningen, The Netherlands
(0.25-m refl.):  Sept. 22.85 UT, 10.9; 23.87, 11.0; Oct. 12.89,
10.8; 14.83, 10.8.

                      (C) Copyright 1998 CBAT
1998 October 17                (7030)            Daniel W. E. Green

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