Thanks ,
Greenhalgh & Laser Jack for the come-back and basic 101.

I have a another question, what about this image from Italy "Col Druscie Observatory"


http://aac.sunrise.it/comete/2002V1-030123ds.jpg


Question #1. What kind of image is that ? Infrareds ?

Question #2. The Italian astronomer is saying something to the effect that there is
"evidenzia una seconda coda"

evidence of a second coma ,or core(nucleus)??

Can you explain that ,please.

The core is a prefect Ball.

http://acc.sunrise.it/comete/2002v1.htm

Question #3. If they are right about a second coma(core),or nucleus in a prefect ball circle shape form, also looks like a couple of outer shields in that image.

Q- Is this common ?

Thanks again, for the 101 [img]/phpBB/images/smiles/icon_smile.gif[/img]