Lorenzo Comolli's Astronomy HomePage

Click on the image for a higher res version - Mouse over for explanation (model overlay by Marco Fulle, INAF/Univ. of Trieste)
Published also on APOD!

This image of comet PanSTARRS shows many synchronic bands in the dust tail, and moreover also the sodium tail and the trail on the orbit (type III tail) are visible. Processing of this image involved the combination of 7 frames and the superimposition of a Larson-Sekanina processing. Tracking was done on the comet.
For a very interesting description of the comet tail in these images, please read the blog of Bob King. And the APOD caption.
Here below are other versions.

Same as the first, but only luminance, without colors.

A simple average of all raw images, without the use of Larson-Sekanina filter, only DDP. A very little hint of the synchronic bands is visible even if no LS was used.

A median combine with the addition of hard enhancement of Larson-Sekanina filter.

Technical Data
Optics	TEC 140
Focal Length	1011 mm
Focal Ratio	f/7.2
Exposure Time	14 min (7x120 s) with luminance filter (color version: LRGB with addition of 2x60s for each color in binning 2x2)
CCD	SBIG STL-11000
Location	Tradate (VA), Po valley, Italy at 300 m height
Date	21 March 2013, 18.56 UT
Mount	Gemini G-41
Tracking	Lodestar on an 80mm f/5 refractor, guiding on the comet
Temperature and humidity	T= 8°C, RH=50%
Sky brightness at zenith (with SQM-L)	17.5 mag/arcsec^2 (Moon in the sky)
Notes	Color frames were gathered when the comet was setting and so they are not of good quality. Selected for APOD of March 30, 2013!