Central Bureau for Astronomical Telegrams
IAUC 2252: N Cyg 1970; 1969i
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Circular No. 2252
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Cable Address: SATELLITES, NEWYORK
Western Union: RAPID SATELLITE CAMBMASS
NOVA CYGNI 1970
Dr. Ch. Bertaud, Paris Observatory, Meudon, reports that
images of the nova have been found on Schmidt plates taken on May
27.028 (magnitude 9.8) and June 2.042 (magnitude 10.3). On 1969
Dec. 9 the nova must have been fainter than magnitude 15.
COMET BENNETT (1969i)
Dr. R. L. Waterfield writes that long-exposure plates of the
comet were obtained at Woolston by M. J. Hendrie, H. Morgan, R.
South and himself on eight nights during the first half of April
and on five nights during May. Throughout April the strong type II
tail remained fairly constant and showed little structure beyond
being broken up into a number of diffuse diverging streamers. In
the best skies it extended for 11o, the p.a. of its middle part
increasing from 275o to 295o. On April 1 and 2 a comb of five nearly
straight, narrow streamers of length 5o to 8o lay outside the northern
border of the type II tail with p.a.'s ranging from 281o to
296o. On April 4 a strong, highly distorted type I tail was directed
to p.a. 302o; its root, which was separated from the head by
75', emerged as a right-angled kink from the northern edge of the
type II tail. At 6o from the nucleus the type I tail became
fainter and fanned widely to reach the northern edge of the plate after
a further 2o and the preceding edge after 3o.5. On April 7 a type I
tail - a nearly straight, narrow fan with irregular internal
structure - extended for 13o.5 in p.a. 292o and formed a 10o fork with
the type II tail. On April 9 a type I tail, similar to but fainter
than that of April 4, emerged from the northern border of the type
II tail 85' from the nucleus, in p.a. 302o; at 4o from the nucleus
it turned slightly south, then widened and curved north for a total
length of 11o.5 from the nucleus; it was much distorted. On April
10, 11 and 14 there was little or no sign of the type I tail; on
April 11, in an exceptionally transparent sky, Waterfield traced
the type II tail for 25o with the naked eye. On May 4 and 6, when
the earth was near the comet's orbit plane, the type II tail was
straight and 9o long, but there was no sign of a sunward beard. On
May 23 to 28 the tail was again curved (in the reverse direction
from previously) and about 2o.5 long. On May 26 there was a strong,
straight, linear streamer running up the center of the tail and
another rather more diffuse one inclined about 20o to it well outside
the concave (following) border of the dust tail. On May 28 (in
poor transparency) numerous fine, straight streamers spread in a
broad fan more or less symmetrically on either side.
1970 June 12 (2252) Brian G. Marsden
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