Comet 17P/Holmes - 1 Nov 07

The comet tail is fan-shaped, with an aperture of about 90°. This is due to the small angle of the tail respect our line of sight (about 17°). The tail is best visible with a blue filter as shown in the highly processed image below. The tail components are at position angles between 165° and 270°, extending from the optocenter at least 1°. The dust coma is 11' diameter and the gas coma is about 42'.

A GIF animation of 8 about hours time interval that show internal structures evolutions and expansion. Larson Sekanina 10°.

A logarithmic photometric profile in the sunward direction show the real dimensions in arcminutes.

Technical Data
Optics Schmidt camera 400/300/615 (Zen optics)
Focal Lenght 615 mm
Focal Ratio f/2,0
Exposure Time Total 3h46m in frames of RGB 30:60:120 s each.
CCD A camera with Kaf-6303e
Sensor Kaf-6303e class 1
Filters RGB Astronomik
Chip emperature
Location Tradate (VA, in Pianura Padana, Italy) at 300m height
Date and time of exposure start 1-2 november 2007, RGB 2.46 (2 nov) - 23.21 (1 nov) - 20.34 (1 nov) UT
Mount Astrosystems fork mount
Tracking -
Temperature and humidity T=6°C, RH=98%
Notes Internal coma elaboration with Larson-Sekanina. Stars color alignment to compensate comet motion.

HTML Editing and Publishing by Lorenzo Comolli. Email me at
Back to Main Page