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IAUC 6428: 1996 N1; 4U 1636-536 AND 4U 0614+091; N Cas 1995

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                                                  Circular No. 6428
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
Phone 617-495-7244/7440/7444 (for emergency use only)


COMET 1996 N1
     A. Hale, Cloudcroft, NM, reports the visual discovery of a
comet by Howard Brewington (also of Cloudcroft).  Available
observations:

     1996 UT             R.A. (2000) Decl.        m1    Observer
     July  4.177     11 33.5       + 4 06        10     Brewington
           4.35560   11 34 01.33   + 4 13 13.7          Garradd
           4.35647   11 34 01.49   + 4 13 16.8            "
           4.35739   11 34 01.62   + 4 13 20.9            "
           4.36856   11 34 03.61   + 4 13 59.6            "
           4.36955   11 34 03.73   + 4 14 02.9            "

H. J. Brewington (Cloudcroft, NM).  0.20-m reflector.
G. J. Garradd (Loomberah, N.S.W.).  0.25-m f/4.1 reflector + CCD.
 Some cirrus clouds.  Coma diameter about 5' on a 300-s exposure.


4U 1636-536 AND 4U 0614+091
     M. van der Klis, Astronomical Institute "Anton Pannekoek",
University of Amsterdam; J. van Paradijs, University of Amsterdam
and University of Alabama in Huntsville; W. H. G. Lewin,
Massachusetts Institute of Technology; F. K. Lamb, University of
Illinois, Urbana/Champaign; B. Vaughan, California Institute of
Technology; E. Kuulkers, Astrophysics Division, ESTEC, European
Space Agency; and T. Augusteijn, European Southern Observatory,
report:  "RXTE observations of 4U 1636-536 performed on Feb. 28.24-
28.35 UT show two simultaneous kHz quasiperiodic oscillations
(QPOs) at frequencies of 898.7 +/- 1.4 and 1171 +/- 11 Hz.  Power
spectral peak widths are 28 +/- 5 and 88 +/- 26 Hz (FWHM),
respectively, and root-mean-square amplitudes 6.6 +/- 0.2 and 6.1
+/- 0.7 percent (7-20 keV).  The higher-frequency peak is the
fastest x-ray QPO yet reported.  Two RXTE observations of 4U
0614+091 (cf. IAUC 6426) that were performed on Mar. 16.35-16.46
and Apr. 13.41-13.54 each show a single kHz QPO peak, with
frequencies, FWHMs, and rms amplitudes of 727 +/- 5 Hz, 137 +/- 18
Hz, and 15.8 +/- 0.8 percent; and 630 +/- 11 Hz, 126 +/- 27 Hz, and
16.5 +/- 1.5 percent (2-20 keV), respectively."


NOVA CASSIOPEIAE 1995
     Visual magnitude estimates (cf. IAUC 6358) by M. V. Zanotta,
Milan:  Apr. 6.85 UT, 9.4; 15.12, 8.5; May 20.87, 9.5; June 10.95,
9.9; 30.06, 10.1.

                      (C) Copyright 1996 CBAT
1996 July 4                    (6428)            Daniel W. E. Green

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