72P/Denning-Fujikawa remeasured
This comet was discovered a long time ago. I found photographic
plates of this comet at the back of the shelf which had been long forgotten.
I have remeasured these plates and suspect that some have been measured
for the first time. This is the lost comet Denning-Fujikawa.
The comet was visually discovered by Denning of the U.K.
in 1881. It is supposed to have been orbiting the sun in a 9-year period,
but had not been recovered until Mr. Fujikawa chanced upon it in 1978.
Since then, it must have orbited the sun three times. I searched for it
frequently at Geisei using the 60cm reflector under favorable conditions
but no success. The image of this comet shining in Leo in October 1978
is deeply etched in my mind. It was very diffused at 10th magnitude, but
photographs taken by the 40cm "comet" telescope showed the nucleus
quite clearly. In those days I only used 6x9cm glass photographic plates,
mostly Fuji FLO-II plates. In those days I used the SAO Star Catalog and
used three comparison stars, but for these new measurements as many as
9 stars were used. They are faint stars all close to the comet, so the
measurements must be more accurate.
72P/Denning-Fujikawa(1978 T2)
1978UT α (2000.0) δ m1
Oct.11.80729 10 23 18.34 +07 06 33.5 9.6 372
29.76806 10 16 41.30 +17 39 24.8 13.6 372
29.78993 10 16 41.53 +17 39 52.7 12.6 372
31.80799 10 17 21.11 +18 20 58.1 12.5 372
Nov. 2.80069 10 18 04.38 +18 58 36.8 13.3 372
The photographs used for the new measurements were taken
by the 40cm telescope on October 11, when the comet was at the brightest.
Its image is perfectly round and the tail is completely invisible. Is this
image really that of the lost comet which had been seen only once in one
hundred years?
My next report will be about another unlucky comet Haneda-Campos.
Comet Denning-Fujikawa
7-minute exposure from 4:19 on October 12, 1978
40cm f/5 reflector, FLO-II photographic plate
