Galaxy Classification Quiz Information

Well, I watched this movie called "Galaxy Quest" but it didn't have much information about galaxies. However, it was a very good movie nonetheless. Just don't be taken in by the title and start thinking it may be all about Galaxies because it certainly is not.
Actually it is a Dramatic Comedy if there is such a thing. Sort of a spoof on Star Trek.

Well, I watched this movie called "Galaxy Quest" but it didn't have much information about galaxies. However, it was a very good movie none the less. Just don't be taken in by the title and start thinking it may be all about Galxies becasue it certainly is not.
Actually it is a Dramatic Comedy if there is such a thing. Sort of a spoof on Star Treck.

Nice game. My new fav

Wow that is very interesting. I would not have guessed it would have been a barred spiral galaxy, of which you said evidence is growing to support this.

Another thing is that interesting is that ... "It is currently thought that most, if not all galaxies, including the Milky Way, contain supermassive black holes at their galactic centers."

Actually, "SB" is a barred spiral. Confusingly, "Sb" is a subtype of Spiral. So barred spirals have to be SBa, SBb, SBc (or, more recently, SBd). There is also an SBm category for somewhat irregular barred spirals.

"Normal" spirals are the same way, but with just an "S" instead of "SB".

To make it even worse, sometimes galaxies are given two lowercase letters to indicate intermediate types. So Sab is halfway between Sa and Sb on the scale.

The Milky Way has long been depicted as a "normal" spiral, but as we can't see it from the outside, it's kind of hard to tell. In the last few years, evidence has accumulated that the Milky Way is a barred spiral, probably SBbc.

I put quotes around "normal" when talking about spirals, as it is thought that between 50 and 75 percent of spiral galaxies are barred spirals. Makes you wonder what is normal.

I am guessing we are in a "SB" normal spiral galaxy. It seems to resemble our galaxy the most.

I am always interested in stuff like this!

Well, correcting the mistakes in the previous comment:

Lenticulars have a number which is zero (not a "lowercase" number, whatever that would be) for secondary designation.

And of course, lenticulars have "a" number not "an" number...

This will require a lot of guessing, so I'll provide a "cheat". If you don't want that, don't read this. Of course, just going to the Wikipedia page would do you good for a cheat. Otherwise, it works like this:

Elliptical galaxies, Spiral galaxies and Barred Spiral galaxies have primary designations of E, S, and SB; respectively. Lenticular galaxies have an S designation, like spirals.

Subtypes are indicated by a secondary designation, either a number or a letter. So, for example: E4, Sa, SBb.

For ellipticals, it's an number, and related to quantifiable physical parameters of the galaxy. The number can be as low as zero, and pretty much no more than 7. In this image, they are E0, E3, E5 and E7.

Spiral galaxy subtypes are indicated by a lowercase letter, either a, b, or c (a d was added later by other astronomers).

So, SBb and Sa are examples.

Lenticulars have a lowercase number, which is a zero.

More about galactic morphologies here (including the original image):

http://hubblesite.org/newscenter/archive/releases/1999/34/image/o

or here:

http://en.wikipedia.org/wiki/Galaxy_morphological_classification

The image on its wikipedia page:

http://en.wikipedia.org/wiki/Image:HubbleTuningFork.jpg

The image is in the public domain.