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IAUC 3540: AG Dra; COMET ON PSS; (1865); 1980h

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                                                  Circular No. 3540
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. B. Kaler, Astronomy Department, University of Illinois,
reports: "Observations made at Prairie Observatory on Nov. 11 UT show
that AG Dra has undergone a major brightening event some time within
the past 30 days.  With the star still near maximum brightness
on its normal light curve, u has increased by 2.0 mag.  The brightening
is inversely correlated with wavelength: 0.6 mag at 650.3 nm
and 0.9 at y.  The brightness at y and u appears to have decreased
by ~ 0.1 and 0.15 mag, respectively, over an 11-hr period."

     J. Dengel and R. Weinberger, Institut fur Astronomie, Innsbruck,
write that images of an unidentified comet appear on POSS
prints No. 1172.  On the 12-min O exposure a small, slightly diffuse,
elongated, weak spot of mean diameter ~ 5" and magnitude 19
(+/- 1 mag) is visible.  On the 50-min E exposure an insignificantly
diffuse trail ~ 0'.2 long is seen.  An extremely faint, narrow tail
~ 1' long is visible (p.a. ~ 250o).  The positions (+/- 3") on the O
and E prints (x = 231 mm, y = 155 mm from the lower left corner):

     1954 UT             R.A. (1950) Decl.
     Aug.  8.36667   22 31 19.4    -23 55 49
           8.39167   22 31 18.5    -23 55 56

The comet's daily motion is 10' in a direction 60o west of south.

     A. Harris, Jet Propulsion Laboratory, reports that he and
J. Young find a 1.5-magnitude amplitude lightcurve, corresponding to a
rotation period of 6h47.5m +/- 5.0m, from observations made at Table
Mountain Observatory.  There was a maximum on Nov. 5.500 UT, with
V = 14.6

     Total visual magnitude estimates and coma diameters: Nov. 2.38,
8.4, 6'.0 (J. Bortle, Stormville, NY, 20 x 80 binoculars); 6.38, 8.2,
- (D. W. E. Green, 20 x 80 binoculars); 9.25, 7.9, 7' (C. S. Morris,
Harvard, MA, 20 x 80 binoculars); 13.42, 7.4:, ~ 10' (Morris).

1980 November 17               (3540)              Daniel W. E. Green

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