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IAUC 4552: PULSAR IN M15; 1986l; 1988A

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                                                  Circular No. 4552
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM    Telephone 617-495-7244/7440/7444

     A. Wolszczan, National Astronomy and Ionosphere Center,
Arecibo; J. M. Middleditch, Los Alamos National Laboratory; S. R.
Kulkarni, California Institute of Technology; D. C. Backer, University
of California, Berkeley; and A. S. Fruchter, Princeton University,
communicate:  "A 110-ms pulsar has been discovered in the direction
of M15 (NGC 7078) at R.A. = 21h27m33.1, Decl. = +11 56'49" (equinox
1950.0), during a survey of globular clusters for pulsars at
the Arecibo radio telescope.  Data recorded at 1.4 GHz on 1987 Dec.
28 were analyzed at the Cornell National Supercomputer Facility,
yielding the following parameters of the pulsar: dispersion measure
= 58 +/- 1 pc/cm3; period = 0.110 664 734 +/- 0.000 000 005 s (epoch
1987 Dec. 28.789 UT); mean flux density at 1.4 GHz = 0.4 +/- 0.1 mJy.
Further work is in progress to confirm the association of this
object with M15 and to refine the pulsar parameters."

     K. Meech, Institute for Astronomy, University of Hawaii,
reports: "CCD observations of comet Wilson obtained on Feb. 14, 15,
and 16 under photometric conditions, with the University of Hawaii
2.2-m telescope on Mauna Kea, show a possible split nucleus.  A
round 'condensation' appeared about 9".1 +/- 0".1 from the nucleus at p.a.
= 119 deg +/- 2 deg on each of the three nights.  The feature is obviously
associated with the comet, as all other objects on the CCD frame
are significantly trailed since the telescope was tracked at the
cometary rate.  Another image taken Feb. 13 also shows the feature,
but measurement is difficult due to a nearby bright star.  Preliminary
Mould r magnitudes (within a 5"-radius diaphragm) for the nucleus
and the feature were about 14.6 and > 15.3, respectively; these
brightnesses did not change appreciably over the three nights."
     Total visual magnitude estimates: Feb. 8.25 UT, 12.3 (A. Hale,
Las Cruces, NM, 0.41-m reflector); 13.22, 13.0 (C. S. Morris,
Whitaker Peak, CA, 0.26-m reflector); 14.85, 13.2 (S. Korth,
Dusseldorf, West Germany, 0.36-m reflector); 16.24, 12.5 (Hale).

     Visual magnitude estimates:  Jan. 29.75 UT, 14.7 (R. McNaught,
Siding Spring Observatory); Feb. 14.4, 14.9 (D. Patchick, Mojave
Desert, CA); 15.37, 14.8 (J. Griese, Rocky Hill, CT).

1988 February 22               (4552)            Daniel W. E. Green

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