View Full Version : Milky Way type and twin

Tom Mazanec
2015-Dec-06, 03:37 PM
Can someone give me a galaxy which has the same classification as the MW, with all the subtypes, is about the same size and is clearly visible with arms, bar, etc...just as the MW would look from another galaxy?

2015-Dec-06, 03:48 PM
Looking for cover art? Hopefully someone can help you out.

2015-Dec-06, 03:55 PM
Seeing as we dont know what the Milky Way looks like from the outside, that would be hard.

2015-Dec-06, 04:19 PM
According to this recent article, quote,

We note that NGC 3521 is a near twin to the Milky Way, having a similar luminosity, scale length, and rotation curve.

The Surface Density Profile of the Galactic Disk from the Terminal Velocity Curve


Although to what degree it actually "looks the same" I'm not sure...

2015-Dec-07, 03:33 PM
There is a difference in appearance given that the MW is a barred spiral.

2015-Dec-07, 03:37 PM
NGC 1232 is also mentioned often in this context - small bar, open multi-armed spiral.

In de Vaucouleurs' system, our classification has been given as SAB(rs)bc (funny how many of those are transitional).

NED has the ability to search published classfications in detail - if I got the pointers right, this query (http://ned.ipac.caltech.edu/cgi-bin/OBJatt?delimiter=bar&nondb=row_count&crosid=objname&position=ra%2Cdec&enotes=objnote&position=pretype&position=z&position=zflag&attdat_CON=M&attdat_CON=S&attdat=attned&gphotoms=q_value&gphotoms=q_unc&gphotoms=ned_value&gphotoms=ned_unc&diamdat=ned_maj_dia&distance=avg&distance=stddev_samp&M=1168&M=1006&M=1576&M=2332&M=996) gets a list of the 143 spirals listed as sharing this classification.

2015-Dec-08, 01:12 PM
Here's an interesting and recent paper by Giovanni Carraro

The Milky Way disk

Clearly there are no general consensus, and
much work still needs to be done. This is particularly
relevant for the spiral structure of the Milky Way,
which is often deemed to be understood. However, even
the Orion arm, where the Sun is located in, nature is


This is another interesting paper, albeit from 2010:

On the Spiral Structure of the Milky Way Galaxy

Quote: our Galaxy resembles stronger the galaxies like NGC 3124, NGC 3992 or NGC 2336

There are pictures of these galaxies towards the end of the paper.


2015-Dec-08, 02:14 PM
Are there any illustrations of the MW that include the dwarf galaxies colliding with us relative to our location?

2015-Dec-09, 01:36 PM
Are there any illustrations of the MW that include the dwarf galaxies colliding with us relative to our location?

I thought it's been established that the dwarf galaxy collisions are illusions?
There was that press release a few months back about the rippling, warping and flaring of the outer disk which gave a false impression of colliding galaxies.

Here's another Giovanni Carraro paper, see particularly figures 7 and 8 which purport to show how this came about.

The Milky Way thin disk structure as revealed by stars and young open clusters

<<...models of Galactic structure need to be revised
by removing this artificial cut-off and properly model the Galactic warp and flare. This will
help prevent observations’ mis-interpretations, like the one of the Canis Major galaxy and the
Monoceros ring...>>