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IAUC 3514: 1980n; H 2252-035; 1980k

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IAUC number

                                                  Circular No. 3514
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 617-864-5758

     M. P. Candy, Perth Observatory, reports that P. Jekabsons has
recovered this comet as follows:

     1980 UT             R. A. (1950) Decl.        m1
     Sept.10.49722    17 12 11.54   -24 25 52.0    18
          11.50524    17 13 25.84   -24 24 04.6

The object is diffuse, with condensation but without tail, and in
close agreement with the prediction on MPC 5043.

H 2252-035
     N. E. White and F. E. Marshall, Goddard Space Flight Center,
write: "A HEAO-A2 observation made on 1978 Dec. 5 reveals that the
x-ray flux of H 2252-035 is modulated with a period of 805 +/- 5 s.
The modulation is sinusoidal with a peak-to-mean amplitude of ~ 40
percent.  The optical period of 859 s (cf. IAUC 3511) is a beat
between the x-ray pulse period and the 3.59-hr orbital period."

     J. Patterson and M. Garcia, Harvard-Smithsonian HEAO A-3 Team,
communicate: "Analysis of HEAO A-3 data from a pointed observation
on 1978 Dec. 5 and of Einstein IPC data on 1979 May 25 confirms the
existence of x-ray pulsations.  The pulsed fraction is 85-100
percent, and the wave form is closely sinusoidal.  The period is not
well determined, but the best fit is obtained for P = 804.7 +/- 4 s,
consistent with the period reported by White and Marshall (above).
This is almost certainly the rotation period of the compact star.
Comparison with the optical data indicates that the 859-s optical
pulsations probably arise from reprocessing of x-rays in the
atmosphere of the secondary.  The x-ray spectrum indicates a
bremsstrahiung temperature ~ 8 keV, as is typical for cataclysmic

     Total visual magnitude estimates and coma diameters: Aug.
31.19  UT, m1 = 12.6, d = 1'.5 (D. Machholz, San Jose, CA, 0.25-m
reflector); Sept. 7.20, 12.9, 1'.5 (Machholz); 8.04, 11.5, 2'.2 (3.
Bortle, Stormville, NY, 0.32-m reflector); 9.04, 11.4, 2'.2 (Bortle);
12.04, 11.6, ~ 2' (Bortle).

1980 September 16              (3514)              Brian G. Marsden

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