Comets

(3200) Phaeton

From Dec 14 to 20 2004, I made some pictures of the now extinct comet (3200) Phaethon. Seiichi Yoshida directed an international campaign in order to detect an eventually tail of this object. (3200) Phaethon is believed to be the ancestor of the geminid meteor shower. The results of the observational campaign are here.

(3200)Phaethon_14dec2004

(3200)Phaethon_18dec2004

(3200)Phaethon_20dec2004


C/2004Q2 Machholz

Still images of C/2004Q2 Machholz taken at Gnosca in winter 2004/05. Gianluca Cassina measured the absolute escape velocity of the ion tail obtaining 200 ± 60 km/s in the evening of Jan 4 2005.

(C2004Q2)Machholz_assembly


51P Harrington

The comet 51P Harrington showed 2 comas.

(51P)Harrington_12gen2002


P/2004V5 LINEAR-Hill

The comet P/2004V5 LINEAR-Hill also broke in several pieces.

(P2004V5-A&B)LINEAR-Hill_18mar2005


17P Holmes

The outburst of Comet 17P Holmes imaged in the winter season 2007/08. The images were taken at the observatory. The addition and assembly were made by Jonathan Muri.

Jonathan also calculated the absolute expansion velocity of the coma from October to January:
SUNWARD” EXPANSION: 324 ± 23 m/s.
LEFT” EXPANSION: 432 ± 26 m/s.
RIGHT” EXPANSION: 450 ± 27 m/s.
The “sunward” expansion was about 70% of the lateral expansions (left or right).
Taking into account only the first two days, from Oct 27 to Oct 28, the expansion velocity was:
SUNWARD” EXPANSION: 582 ± 37 m/s.
Extrapolating back, the outburst time occured: OCT_24_2007 at 07:30 UTC ± 6H.


C/2007N3 (Lulin)

I assembled 83 30-s CCD images to produce this animation of comet C/2007N3 (Lulin).
The animation spans about 1h and one can see the movement of the ion tail.
No special filters or processing techniques were used.
Date: Feb 17th 2009  Time: frm 00:51 to 00:52UT

I assembled 500 30-s CCD images to produce this animation of comet C/2007N3 (Lulin).
The animation spans about 5h. The very beautiful movement of the ion tail can be seen.
Date: Feb 21-22 2009  Time: from 23:00UT to 03:53UT
I assembled 604 30-s CCD images to produce this animation of comet C/2007N3 (Lulin).
This 12s animation compress about 6h real time.
Date: Feb, 24-25, 2009  Time: from 20:40UT to 02:43UT.