Central Bureau for Astronomical Telegrams
IAUC 3257: V1500 Cyg; 1978f; Notice
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Read IAUC 3258
Circular No. 3257
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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
V1500 CYGNI
J. C. Kemp, R. King and P. E. Johnson, Physics Department,
University of Oregon, write: "Photometry in unfiltered light (S-20
response) on the 81-cm telescope at Pine Mountain on seven nights
during Aug. 11-20 showed a lightcurve with predominant period 3.358
hours and peak-to-peak amplitude 0.32 magnitude. Some suggestion
of a double period (6.7 hours) has appeared again: see Kemp, Sykes
and Rudy (1977, Astrophys. J. 211, L71). Our current ephemeris in
terms of the possible double period is 1978 Aug. 1.55661 + 0.21984
E. This epoch seems to correspond to the deeper of the two minima;
and the first maximum, in this phasing, is the higher of the two.
The maxima are decidedly peaked; in general, the curve appears
ellipsoidal in character, rather than of an eclipsing type. Since
the double period may well be a spurious statistical effect,
comparison with current lightcurves by other observers is urgently
sought. The mean magnitude in unfiltered light was estimated as
13.4, roughly a V magnitude; but the nebular lines, which presumably
do not manifest the 3-hour variation, should be subtracted.
Thus the nuclear object is fainter, and the true variation amplitude
is deeper than noted above."
Recent visual magnitude estimates at the Harvard Observatory:
July 1.18 UT, 14.3 (D. W. E. Green); 13.23, 14.2 (S. O'Meara).
COMET MEIER (1978f)
Further total visual magnitude estimates: July 12.10 UT, 7.9
(J. Bortle, Brooks Observatory, 32-cm reflector); 14.11, 8.3 (P.
Maley, Houston, Texas, 15-cm refractor).
NOTICE TO CONTRIBUTORS
Repeating the notice on IAUC 3231, we request that material
for these Circulars (and for the Minor Planet Circulars) generally
be communicated to us, either by TWX/telex/telegram/cablegram to
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to the private home number of the undersigned should be made only
in cases of extreme urgency.
1978 August 25 (3257) Brian G. Marsden
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