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(meteorobs) Hale-Bopp 2/28
Here is my description of the comet for the morning of February 28, 1997.
The comet's naked-eye view was stunning, despite moonlight. It clearly
outshone Deneb and Altair, but was still at a half-magnitude fainter than
Vega. I put the total magnitude at 0.6. The tail could be seen for about 2
degrees.
In 20x80 binoculars the tail components were measured as follows:
westward-most border of dust tail was 3.5 degrees long in p.a. 287 degrees,
bright spine was 4 degrees long in p.a. 304 degrees, and the eastward-most
border of the gas tail was 5 degrees long in p.a. 323 degrees. The dust
tail was the brightest part of the complete tail system for the first 1.5
degrees and then it rapidly decreased as it fanned out. The gas tail seemed
to change little in intensity from the point where it exited the coma until
about 4 degrees and then it dropped in brightness. It seemed obvious that
the bright wedge of material was still present from previous mornings and
was still bordered by jets extending southward and westward, but when seen
at high power with the reflector everything resolved into a bit different
picture.
I made a detailed drawing of the comet's features with respect to the stars
visible within the reflector and it is posted at
http://medicine.wustldot edu/~kronkg/hb199702.html. It represents the
appearance of the comet on February 28.48 as seen through my 33.3-cm
reflector at 200x and 500x.
The high power view revealed an intense emission at p.a. 166 degrees, a
fairly strong emission at p.a. 248 degrees, which helped feed the bright
tail spine on the inside of the dust tail, and a faint emission at p.a. 48
degrees that formed the inside edge of the gas tail. The area of the
"bright wedge" seen in binoculars was actually filled with three
distinct hoods and one very faint one. The total of four hoods decreased in
brightness as you moved away from the brilliant, nearly stellar nucleus
(magnitude possibly 2.5, after comparison with stars far outside the field
of view). The hood closest to the nucleus seemed to be emitting directly
out of the emission at p.a. 166 degrees, as there was a subtle
"fountain" effect present. This hood's westward side was very
bright and curved back to the jet at p.a. 248 degrees. The eastward side
was very faint and extended to the fainter jet at p.a. 48 degrees. The
second hood was fainter and more diffuse than the one closest to the
nucleus. It was not connected to the first hood or the bright emission at
p.a. 166 degrees. It was also brightest on its westward side and fanned out
as it approached and connected with the emission at p.a. 248 degrees. A
very faint eastward emission of this hood curved toward the faint emission
at p.a. 48 degrees, but never quite made it. The third hood is fainter and
more diffuse than the second. It is also brighter on the westward side, but
fanned out considerably as it curved toward the emission at p.a. 248
degrees. The westward border of this hood seemed to help form the westward
border of the bright tail spine. There was no apparent eastward extension
of this hood. The fourth hood was glimpsed several times, and its distance
from the third hood was noted, but its outer (NW) border was never traced
very far, and there was never a hint of an eastward extension.
Gary