19P/Borrelly
The analysis of the second condensation/knot of 19P/Borrelly:
19P/Borrelly � by Bernhard Haeusler, Germany; Gustavo Muler,
Spain; Esteban Raina Lorenz, Spain; Josep Bosch, Spain; Fran�ois
Kugel, France,
Albert Sanchez, Spain
After checking the .fits image of Gustavo Muler, Esteban Raina Lorenz, Josep Bosch, Fran�ois Kugel, Albert Sanchez and my own images, I come to the following interim conclusion:
Above you find the
history of our observations. BH means Bernhard Haeusler, GM means Gustavo Muler, EL
means
Esteban Raina Lorenz,
JB means Josep Bosch and FK means Fran�ois
Kugel.
The red marking lines are showing the second condensation, the Italian colleagues
around Giovanni Sostero and also Fran�ois Kugel from France reported.
See IAUC 9044
(2009-05-18).
I can follow back this second condensation until April,
2 for sure on my
images.
My "detection" at May, 7 is marked with yellow lines. This "knot" is not visible on
other images and probably a temporary bulge in the tail..
Pay attention, that the comet decreased its magnitude since March from 17mag to
18mag. This has a visible effect on the images. The inlay images are enlarged
with factor 8.
The colored lines
(except red and yellow) represent around 5.6 arcseconds corresponding to the
focal length of each observer's telescope and the used ccd camera
and binning, to make sure,
that we are talking about the same thing.
The knot is not visible on each image
since April, 2, but on the most. Also the quality of the seeing and small
guiding errors are
influencing the significance of the images.
It is interesting, that
the knot is obviously not changing its position corresponding to the false
nucleus since April, 2. The knot is embedded in the sunward tail of
19P/Borrelly. The
sunward tail has a direction of about 297� and didn't change significantly
its direction this year.
We can clearly observe a
feature in the sunward tail in about 5 arcsec distance of the false nucleus in
position angle ~302�.
The morphology of the coma and tail of comet 19P/Borrelly was studied after the
flyby of the probe Deep Space 1 in September 2001.
The scientists found on the probe's images a complex structure of two jets and
two fans, but no evidence of any fragment in the close area of the nucleus.
We can assume now, that the comet is currently sending jets from the opposing pole in roughly direction to the Sun.
Many thanks to all observers for sending me their .fits images! This was very helpful for the analyses.
Good luck for the next observations!
Final conclusion after the hints of Dr. Nalin Samarasinha of the PSI Planetary Science Institute
links:
http://astrosurf.com/cometas-obs/index_i.htm Visual and CCD Observations and images from the "Cometas Obs" mailing list, using the Focas II format
es.groups.yahoo.com/group/Cometas_Obs The Spanish comet observation group in Yahoo