That's another fascinating galaxy portrait, Adam.
NGC 210 is a very interesting-looking galaxy, typical and untypical at the same time.
It is typical of largish spiral galaxies to have a white-looking nucleus, a yellow bulge an blue spiral arms. If the galaxy is barred, it is normal for the spiral arms to originate at the ends of the bar. NGC 210 displays all these features, more or less, so in that way it is typical. But there are interesting irregularities.
NGC 210 has a bright and very yellow lens immediately surrounding the nucleus. This may not be untypical, but the bright yellow lens is unusually obvious here. The lens may be the remnant of one or many intense ring-shaped starbursts surrounding the nucleus. Many spiral galaxies do indeed have such bright inner rings, but the rings are often bluish because they contain many young stars. In the case of NGC 210, star formation in the ring has ceased long ago, and what is left is a richly populated and therefore bright inner ring made up of old yellow stars.
NGC 210 has an inner disk which is much less bright than the yellow lens, but like the lens the inner disk is generally yellow in color. There are many old yellow stars here. There are some fine dust lanes threading a fine pattern through the inner disk, and two not very bright slightly bluish spiral arms seem to be superimposed on the inner disk. The arms seem to emerge from opposite sides of the yellow lens. The arms contain some star formation, but not a lot. But there are some interestingly pink areas in the dust lanes.
Outside the inner disk is an apparent "gap", which seems to contain very few stars at all. The main "body" of the galaxy seems to end here. This inner "body" of the galaxy is very well-ordered, generally oval-shaped and "quiescent-looking".
Some distance from the inner disk the galaxy changes character. Two very blue spiral arms begin on opposite sides of the inner disk, but some distance away from the visible disk. The general structure of the galaxy is slightly similar to famous barred galaxy NGC 1300, but with two differences - NGC 1300 is not obviously barred at all, and the spirals arms are not "attached" to the galactic "body", as they are in the case of NGC1300.
The "gap" between the galactic "body" and the arms is slightly reminiscent of a ring galaxy:
I also find the contrast between the general shape of the "arm region" and the "disk region" very interesting. The "disk region" is extremely well-ordered while the arm region is a lot more turbulent. But even so, the upper spiral arm is remarkably long, thin and narrow.
A yellow edge-on galaxy is seen in the "arm region" at two o'clock in the galaxy. This galaxy is probably a background object. Two other galaxies are also seen, one very blue barred galaxy at bottom left and a yellow elliptical galaxy at bottom right. Both are background galaxies.
Well, what an interesting galaxy and what a fine picture! Thank you, Adam!
Ann
That's another fascinating galaxy portrait, Adam.
NGC 210 is a very interesting-looking galaxy, typical and untypical at the same time.
It is typical of largish spiral galaxies to have a white-looking nucleus, a yellow bulge an blue spiral arms. If the galaxy is barred, it is normal for the spiral arms to originate at the ends of the bar. NGC 210 displays all these features, more or less, so in that way it is typical. But there are interesting irregularities.
NGC 210 has a bright and very yellow lens immediately surrounding the nucleus. This may not be untypical, but the bright yellow lens is unusually obvious here. The lens may be the remnant of one or many intense ring-shaped starbursts surrounding the nucleus. Many spiral galaxies do indeed have such bright inner rings, but the rings are often bluish because they contain many young stars. In the case of NGC 210, star formation in the ring has ceased long ago, and what is left is a richly populated and therefore bright inner ring made up of old yellow stars.
NGC 210 has an inner disk which is much less bright than the yellow lens, but like the lens the inner disk is generally yellow in color. There are many old yellow stars here. There are some fine dust lanes threading a fine pattern through the inner disk, and two not very bright slightly bluish spiral arms seem to be superimposed on the inner disk. The arms seem to emerge from opposite sides of the yellow lens. The arms contain some star formation, but not a lot. But there are some interestingly pink areas in the dust lanes.
Outside the inner disk is an apparent "gap", which seems to contain very few stars at all. The main "body" of the galaxy seems to end here. This inner "body" of the galaxy is very well-ordered, generally oval-shaped and "quiescent-looking".
Some distance from the inner disk the galaxy changes character. Two very blue spiral arms begin on opposite sides of the inner disk, but some distance away from the visible disk. The general structure of the galaxy is slightly similar to famous barred galaxy NGC 1300, but with two differences - NGC 1300 is not obviously barred at all, and the spirals arms are not "attached" to the galactic "body", as they are in the case of NGC1300.
[img2]http://www.utahskies.org/image_library/deepsky/hst/BarredSpiralNGC1300-HST.jpg[/img2]
The "gap" between the galactic "body" and the arms is slightly reminiscent of a ring galaxy:
[img2]http://images.astronet.ru/pubd/2002/09/09/0001179569/hoag_hst_big.jpg[/img2]
I also find the contrast between the general shape of the "arm region" and the "disk region" very interesting. The "disk region" is extremely well-ordered while the arm region is a lot more turbulent. But even so, the upper spiral arm is remarkably long, thin and narrow.
A yellow edge-on galaxy is seen in the "arm region" at two o'clock in the galaxy. This galaxy is probably a background object. Two other galaxies are also seen, one very blue barred galaxy at bottom left and a yellow elliptical galaxy at bottom right. Both are background galaxies.
Well, what an interesting galaxy and what a fine picture! Thank you, Adam!
Ann