3 Attachment(s)
Object of the Week, May 27, 2018 Arp 16 – Messier 66
Asymmetrical spiral galaxy
Leo
RA 11h 20m 15.0s
DEC +12° 59′ 30″
Magnitude 8.9 visual
Size: 9.1 x 4.2 arc minutes
Attachment 3067
https://www.adamblockphotos.com/galaxies.html
M66 is one of my favorite galaxies but I’ve seldom taken the time to sketch it. That’s probably because M51 and M101 usually take so much of my eyepiece time during the rare clear Spring nights we get in western Oregon. Last year I finally put it at the top of my list on a very fine night and came away with the beginning of a decent sketch.
Attachment 3068 Attachment 3069
This is about 45 minutes worth of sketching, so I have a good deal more eyepiece time before I’ll come up with a finished drawing. For now, it gives a decent impression of my view in the eyepiece at 408x on a 21.82 SQM night. North is up in my sketch and Adam Blocks photo above.
As you all probably know, M66 has its own Arp number (16) but it's also a part of the Leo Triplet, which includes M66 and NGC 3628, which together with M66 is designated as Arp 317. I’m only highlighting M66 as the OOTW today because it’s the brightest of the three and has the most detail.
The first thing that strikes me about M66 is its distorted spiral shape, with its southern arm being noticeably longer than its northern counterpart. Evidently, gravitational interactions with both NGC 3628 and M65, but mostly with 3628, has twisted M66 into its present shape. These interactions helped create the prominent central bar and enhanced the spiral arm star forming regions that help define M66’s unique shape.
About 95,000 light years in diameter, about the same as our Milky Way galaxy, it is also about 36 million light years away, approximately the same distance as M51. Presented mostly face on we get a good look at the overall structure of this dynamic galaxy and can see not only the brightest areas of the spiral arms but also the dark dust lanes that help define their shapes.
I particularly like the dust lane that separates the northern pointing spiral arm into two distinct parts, as well as how far the southern pointing arm extends from the main body of the galaxy, giving it a distinct asymmetrical look. Adding to this asymmetry are two spiral arm details trailing off the northern tip of the central bar in what looks like the wrong direction. I think they’re actually the beginning of the southern pointing arm.
The long central bar has a small but distinctly bright core which brings some balance to what is an otherwise a somewhat chaotic scene.
There’s a lot to see in M66, so…
"GIVE IT A GO AND LET US KNOW"
