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IAUC 2984: SN IN NGC 5427; X-RAY BURSTS; AM HER = 3U 1809+50

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                                                  Circular No. 2984
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.

     L. Searle, Hale Observatories, reports that R. Wade has discovered
a supernova 35" east and 34" north of the nucleus of NGC 5427.
On Aug. 25 the visual magnitude was 14.5.  A spectrum by J. B. Oke
shows it to be type I.

     W. H. G. Lewin, J. Doty, J. A. Hoffman and F. K. Li, Massachusetts
Institute of Technology, report the following SAS-3 observations
made between Aug. 22.25 and 28.50.

     Source      T(hrs)  N  Delta-T(hrs)   Comments
     MX 1608-52    54    0       -         IAUC 2936
     MXB1728-34    17    2      4.0
     MXB1730-335   17    0       -         Rapid Burster
     NGC 6624      16    0       -         "Steady" source in high state
     MXB1837+05    32    4      6.3*       IAUC 2983
     MXB1906+00    12    1       -           "   "
     Aql MXB        8    0       -           "   "

T = observing time; N = number of bursts observed; Delta-T = burst interval.

*Burst intervals regular (rms jitter ~ 6%).

AM HER = 3U 1809+50
     A. Cowley, D. Crampton, P. Szkody and D. Brownlee report that
simultaneous spectrographic and photometric observations of AM Her
with the Kitt Peak National Observatory 400-cm and 91-cm telescopes
show radial velocity and intensity variations with a period of 186
minutes.  The period agrees with x-ray data.  The prominant emission
lines of H and He II are 1000 km/s wide with complex structure
repeating each cycle.  The semi-amplitude of the velocity curve is
~ 350 km/s.

     The visual light curve shows a broad primary eclipse with minimum
(T = 2443014.705) lasting about 40 minutes with a depth of about
0.7 magnitudes below the maximum brightness of mv ~ 12.3.  A narrow
secondary minimum of about 0.4 magnitudes is present halfway between
primary minima.  Flickering from 0.1 to 0.3 magnitudes is seen at
all phases of the light cycle.

1976 August 30                 (2984)              Richard E. McCrosky

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