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IAUC 3745: Poss. SN IN ESO 308-G16; 1E 2259+586; 1980b

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                                                  Circular No. 3745
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

     J. Maza, Department of Astronomy, University of Chile, telexes
that M. Wischnjewsky has found a possible supernova in the
Sc galaxy ESO 308-G16 (R.A. = 6h34m0, Decl. = -39deg13', equinox
1950.0).  The object is 4" east and 9" south of the galaxy's nucleus.
On the discovery plate, taken on Nov. 11 by L. E. Gonzalez, the object
was of photographic magnitude 16.

1E 2259+586
     J. Middleditch, Los Alamos National Laboratory: and G.
Fahlman, University of British Columbia, write: "Time-series data
taken with the Kitt Peak 2.1-m reflector in the 350-900-nm band at
five separate positions in the field of 1E 2259+586 show power at
285.51 +/- 0.04 mHz during a 1-hr run on candidate D, 2".2 south and
3".3 east of star A, the faint object mentioned by Fahlman et al.
(1982, Ap. J. 261, L1).  Star D is located 3" outside a 6" radius
HRI error circle.  Since star D is 1.5 mag fainter than A in the B
band, the identical R-band relationship (Margon and Anderson, IAUC
3739) is unremarkable.  However, our nearly equal Sept. RCA C31034
count rates for A and D indicate that star D is very red beyond
the R band.  The ~ 3-sigma pulsations correspond to B ~ 25 but could
rise to 20.5 in I.  The 1-mHz downshift of this observation and
the previously observed 285.6-mHz pulsations (IAUC 3701), together
with the weak phase modulation indicated by these observations, as
well as the analysis of the recently corrected Einstein data by
Fahlman and Gregory (1982, Proc. IAU Symp. No. 101), and the true
fundamental pulse frequency of 143.3 mHz, are all consistent with
an orbital period of ~ 2300 s.  In addition, 3-hr and 6-hr sets of
observations of star D in Oct. with the NASA/University of Arizona
1.5-m telescope in the 320-750-nm band did not detect 285.6-mHz
pulsations but possibly detected, on one occasion, 573.2-mHz
(fourth harmonic) pulsations.  From this we conclude that down-shifted
pulsations from star D are not apparent at wavelengths
shorter than 750 nm."

     Total visual magnitude estimate by J. E. Bortle, Stormville,
NY (0.32-m reflector); Aug. 20.09 UT, 12.2.

1982 November 19               (3745)              Brian G. Marsden

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