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IAUC 7313: 2S 1417-624; 10P; LEONID METEORS 1999; V1493 Aql

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                                                  Circular No. 7313
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  ISSN 0081-0304
Phone 617-495-7244/7440/7444 (for emergency use only)

2S 1417-624
     M. H. Finger, Universities Space Research Association, reports
for the BATSE/CGRO team:  "Hard x-ray pulses from the Be/x-ray
transient pulsar 2S 1417-624 are currently being detected.  The
first detection was on Nov. 12.  The average pulsed flux is 16 +/-
3 mCrab (20-50 keV).  After correction using the binary orbit of
Finger et al. (1996, A.Ap. Supp. 120, 209), the pulse timing from
Nov. 12-17 is consistent with a constant frequency of 56.99490(9)
Hz.  The last detection before the current outburst was on 1996
Dec. 21."

     C. W. Hergenrother and S. Larson, Lunar and Planetary
Laboratory, write:  "Unfiltered CCD images of comet 10P taken with
the Steward Observatory 2.3-m reflector by Hergenrother on Nov.
13.15 UT show evidence of shell-like jet-arc coma structure.
Processing with a radial-gradiant filter shows multiple features
spanning from p.a. 30 deg clockwise through p.a. 100 deg and
extending out to 30" in the solar direction.  Brightness
enhancements are visible at p.a. 125 and 345 deg, the latter being
near the predicted position angle of this comet's traditional fan.
Observations over a 1.5-hr span displayed no obvious changes.  The
coma morphology is similar to that reported in Nov. 1988
(Boehnhardt et al. 1990, Icarus 86, 58) and may be the result of
viewing down the fan's emission cone (Sekanina 1991, A.J. 102,
350).  A processed image can be found at

     A rather broad second peak in this year's Leonid display
appears to have occurred around Nov. 18.6-18.9 UT, in which visual
counts of 100-300 meteors/hr were reported by observers in Hawaii
(S. J. O'Meara), Japan (K. Mameda, Y. Kushida, R. Kushida, T.
Kagawa; communicated via S. Nakano), and China (Rui Qi;
communicated via J. Zhu).

     CCD magnitude estimates, unfiltered unless otherwise noted:
Oct. 15.743 UT, V = 15.73 +/- 0.06 (M. Zejda, Brno, Czech Rep.);
31.730, V = 16.22 +/- 0.04 (D. Hanzl, Brno, Czech Rep.); Nov.
1.726, 15.08 (G. Masi, Ceccano, Italy); 15.762, V = 16.1 +/- 0.2

                      (C) Copyright 1999 CBAT
1999 November 20               (7313)            Daniel W. E. Green

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