by Ann » Wed May 27, 2015 4:39 am
geckzilla wrote:I think this object is a good example of a spiral transitioning to a lenticular. The continuous rings and the tight nuclear structures seem common in lenticular galaxies and yet the spiral structures are still evident enough for most people to say it's a spiral.
Interesting observation. I think it is time to compare M94 with yet another galaxy, NGC 4314.
This Hubble picture shows the rather small star forming nuclear ring of NGC 4314, and the inset shows the large barred spiral galaxy in its entirety. There is no star formation in NGC 4314 at all apart from the nuclear ring.
This (blurry) picture gives you an idea of what the nuclear ring looks like in relation to the galaxy as a whole. Although NGC 4314 has a very clear and obvious barred spiral structure, it is definitely on its way to becoming a lenticular galaxy. But first it might pass through transitional stages, like
NGC 7743. That galaxy retains traces of spiral structure, but its star forming days are long gone.
I'm still mulling over the fact that M94 is only 30,000 light years across. That really makes it a quite small galaxy,
half the size of M33, which looks smaller than M94 to me. Perhaps it is the chaotic structure of M33 that makes it look small to me.
Ann
[quote="geckzilla"]I think this object is a good example of a spiral transitioning to a lenticular. The continuous rings and the tight nuclear structures seem common in lenticular galaxies and yet the spiral structures are still evident enough for most people to say it's a spiral.[/quote]
Interesting observation. I think it is time to compare M94 with yet another galaxy, NGC 4314. [url=http://apod.nasa.gov/apod/image/9806/ngc4314_hst_big.jpg]This Hubble picture[/url] shows the rather small star forming nuclear ring of NGC 4314, and the inset shows the large barred spiral galaxy in its entirety. There is no star formation in NGC 4314 at all apart from the nuclear ring. [url=http://en.spaceengine.org/_fr/15/0898593.jpg]This (blurry) picture[/url] gives you an idea of what the nuclear ring looks like in relation to the galaxy as a whole. Although NGC 4314 has a very clear and obvious barred spiral structure, it is definitely on its way to becoming a lenticular galaxy. But first it might pass through transitional stages, like [url=http://skyservice.pha.jhu.edu/DR9/ImgCutout/getjpeg.aspx?ra=356.08803697&dec=9.9341265&scale=0.32&width=812&height=812&opt=&query=]NGC 7743[/url]. That galaxy retains traces of spiral structure, but its star forming days are long gone.
I'm still mulling over the fact that M94 is only 30,000 light years across. That really makes it a quite small galaxy, [url=http://en.wikipedia.org/wiki/Triangulum_Galaxy]half the size of M33[/url], which looks smaller than M94 to me. Perhaps it is the chaotic structure of M33 that makes it look small to me.
Ann