Comet color?

Comments and questions about the APOD on the main view screen.
SkyMaven

Comet color?

Post by SkyMaven » Wed Dec 22, 2004 5:45 pm

Why does Comet Machholz appear green in the photographs? :?:

SkyMaven

Um..

Post by SkyMaven » Thu Dec 23, 2004 7:18 pm

I know you guys are all focusing on the "strange streak", but could one of you pause for a nanosecond and help me out here? :P

Marian

David

Mach principle

Post by David » Thu Dec 23, 2004 11:19 pm

LGM, O2, or V.

SkyMaven

Sigh..

Post by SkyMaven » Thu Dec 23, 2004 11:24 pm

Thanks for that insightful reply. I'm fully satisfied now. Mmmm yeah. My knowledge of the subject just grew by leaps and bounds, it did.

Good grief.

:?

PRN

comet Big Mach

Post by PRN » Thu Dec 23, 2004 11:31 pm

http://www.noao.edu/noao/comets/hy/wiynhy.html

"Different physical components making up the comet are represented by different colors in these false color composites: the dusty material is shown as red, water and ice are shown as green, and carbon emission (basically, soot) is shown as blue"

Note "false color", hence it's up to Adam Block.

ngc1535
Ensign
Posts: 49
Joined: Tue Jun 14, 2005 4:18 am

Re: comet Big Mach

Post by ngc1535 » Tue Jun 14, 2005 4:24 am

I doubt anyone will see this message... but the person that replied below
is mistaken. I used broadband RGB filters and I normalized the color
response of the chip/filter system. In this way I take out (most) of the
instrumental bias and the color that you see is approximately what
we would see with our eyes (if they were as sensitive and could integrate as long as the CCD camera).

I did not choose the colors of the comet (or any other pictures I generate). Most comets's comae glow blue/green due to various
gasses that are being ionized (the gas tails are usually very blue). The
dust tail is usually yellow because it is reflected sunlight.

Adam Block
ablock@noao.edu

PRN wrote:http://www.noao.edu/noao/comets/hy/wiynhy.html

"Different physical components making up the comet are represented by different colors in these false color composites: the dusty material is shown as red, water and ice are shown as green, and carbon emission (basically, soot) is shown as blue"

Note "false color", hence it's up to Adam Block.