Smooth cigar vs bulgeless edge-on disk
What's the difference? If a disk is viewed edge on, how can you tell its a disk, and not smooth? Can I get a few examples of what would go under each type?
by ElisabethB moderator
A bulgeless disk/spiral viewed edge on will have pointy tips, whereas a smooth cigar will have more rounded ends.
But it is not always easy to see. Just give it your best shot !
Happy hunting !
by klmasters scientist, admin
You can sometimes sort of tell the concentration by eye too - an elliptical galaxy should be very centrally concentrated (ie. much brighter in the centre), while a disc will have the light more evenly spread through the visible area. I'll keep an eye out for some good examples and try to post back what I mean later (or @vrooje might have some to hand).