Inquiry Regarding "Size"

Fizzgig

Hi, I've been in reading the Messier Objects page and in the info. there is:

Type:
Const:
R.A.:
Dec:
Size:
Mag:

I'm curious what "Size" means? Thanks.

-Fizzy-

faith_healer

I'm thinking degrees off the top of my head......pointed at that..

Fizzgig

Ah yes...

Well that makes sense. See, I was reading it as feet! I'm like...huh?

Thanks.

Trane Francks · Moderator Joined: 27 Feb 2003 Posts: 870 Tokyo, Japan

The unit is actually minutes. M31, the Great Andromeda Galaxy, is 160' x 40'. There are sixty seconds to a minute and sixty minutes to a degree. To put size into perspective, the moon is approximately 0.5 degrees and that amount of sky can be approximated by holding your arm out and full length in front of you and looking at the diameter of your thumbnail.