(3200) Phaethon
From 14 to 20 Dec 2004, I made some pictures of the now extinct comet (3200) Phaethon. Seiichi Yoshida directed an international campaign in order to detect a 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.
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 4 Jan 2005.
I assembled some gif images showing the motion of the dust tail.
2005_01_04 (8 MB)
2005_01_05 (10 MB)
2005_01_08 (2 MB)
2005_01_10 (10 MB)
2005_01_14 (5 MB)
51P Harrington
The comet 51P Harrington showed 2 comas.
P/2004V5 LINEAR-Hill
The comet P/2004V5 LINEAR-Hill also broke in several pieces.
17P Holmes
The outburts of the comet 17P/Holmes photographed between the clouds
from Gnosca. With an angular diameter of 2,5 arcmin it is roughly 4 times larger than
the angular diameter of Jupiter. Now the comet is a naked eye object in the Perseus constellation. 1s exposure with a Newtonian 40cm f/4.
17P Holmes
The outburts of the comet 17P/Holmes photographed from Gnosca. 1s exposure with a Newtonian 40cm f/4.
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 27 to 28 Oct, the expansion velocity was:
“SUNWARD” EXPANSION: 582 ± 37 m/s.
Extrapolating back, the outburst time occured the: 24 OCT 2007 at 07:30 UTC ± 6H.
C/2007N3 (Lulin)
I assembled 83 x 30 s CCD images to produce this animation of comet C/2007N3 (Lulin).
The animation spans about 1 h and one can see the movement of the ion tail.
No special filters or processing techniques were used.
Date: 17 Feb 2009 Time: from 00:51 UT to 00:52 UT.
I assembled 500 x 30 s CCD images to produce this animation of comet C/2007N3 (Lulin).
The animation spans about 5 h. The very beautiful movement of the ion tail can be seen.
Date:21-22 Feb 2009 Time: from 23:00 UT to 03:53 UT.
I assembled 604 x 30 s CCD images to produce this animation of comet C/2007N3 (Lulin).
This 12 s animation compress about 6 h real time.
Date: 24-25 Feb 2009 Time: from 20:40 UT to 02:43 UT.
19P/Borrelly
101P/Chernykh
53P/Wolf-Harrington
C2006 A1 (Pojmanski)
The comet C/2006 A1 (Pojmanski) photographed in the morning sky of the 14th march 2006 without filters. 37 20-s CCD images were taken. Angular dimensions of the image: 20 x 15 arcmin.
North is up. East is left.
C2005 A1 (LINEAR)
The two comas of the comet C/2005A1 LINEAR photographed in the night of 2005 September 29th. They are 19 arcseconds apart and their luminosities are of 17 mag and 19 mag. North=up ; East =left
