Starship Asterisk*

M65 and M66

Explanation: Nearby and bright, spiral galaxies M65 (top) and M66 stand out in this engaging cosmic snapshot. The pair are just 35 million light-years distant and around 100,000 light-years across, about the size of our own spiral Milky Way. While both exhibit prominent dust lanes sweeping along their broad spiral arms, M66 in particular is a striking contrast in red and blue hues; the telltale pinkish glow of hydrogen gas in star forming regions and young blue star clusters. M65 and M66 make up two thirds of the well-known Leo Triplet of galaxies with warps and tidal tails that offer evidence of the group's past close encounters. The larger M66 has been host to four supernovae discovered since 1973.

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I like M66. It's more colorful, and the red part resembles a horizontal -5-, or a sloppy -S-. Could you really call an object that's so full of dust, unsloppy??

Beyond wrote:I like M66. It's more colorful, and the red part resembles a horizontal -5-, or a sloppy -S-. Could you really call an object that's so full of dust, unsloppy??

Beyond, you're right! The red part in M66 really does look like one large big red "S" or a number "5", possibly somewhat sloppy!

The reason why the central dust lane in M66 looks so red is because the photographer, Bill Snyder, has taken care to extract as much Hydrogen Alpha (Ha) information as he possibly can from M65 and M66. The red color mostly traces hydrogen that has been ionized and made to glow red. Hydrogen can be ionized by different processes, but in the case of M66 (as well as in the Milky Way) it mostly happens when newborn hot stars ionize the dust clouds from which they were born. Therefore Ha emission is an excellent tracer of recent star formation.

And as Bill Snyder so eloquently demonstrates, the major dust lane of M66 is really full of Ha light and star formation! We may also note the distorted shape of M66, which may have helped "slosh the gas together" and precipitate star formation.

By contrast, look at M65! There are no signs of any obviously red patches anywhere in that galaxy, although there may be, possibly, some marginally pink regions. Nevertheless, it is clear that there is extremely little star formation in M65. Note that there appears to be a large ring of dust surrounding the inner bulge of M65, and note, too, that there might possibly be a dusty bar crossing the inner bulge and bridging the large ring. Note that there are some bright and marginally blue patches in the ring at 2 o'clock, which are probably some relatively young clusters. But they are not young enough to produce emission nebulae.

This is an excellent picture with brilliant color information!

Ann

M 65 and M66 are two handsome galaxies.
They have a look interesting.
M 65 is very uniform and symmetrical.
M66 is a barred spiral galaxy.

Fan of APOD for many, many years. I want to my thanks. Also want to say my thanks to NASA GSFC for their efforts on Venus Transit Day. It was a bummer in College Park, MD; clouds, clouds, and more clouds.

Really liked the deep sky photo today. Pies in the Sky, ordering pizza for breakfast!

Seeing the proximity of these (and the third of the Leo Triplet) to each other, I wonder how our own sense of the universe would be different if we had nearby galaxies that would be so visible to the naked eye, and cover so much of the night sky. Would we be a little less self centered? Or would they have been just more 'splotches' like our own Milky Way?

BrianSherwood wrote:Seeing the proximity of these (and the third of the Leo Triplet) to each other, I wonder how our own sense of the universe would be different if we had nearby galaxies that would be so visible to the naked eye, and cover so much of the night sky. Would we be a little less self centered? Or would they have been just more 'splotches' like our own Milky Way?

We can see the sun and moon, a plethora of stars including the Magellanic Clouds, and solar planets yet we still evolved with an egocentric view of the universe. I'd be surprised if adding a big fat spiral galaxy or two to the view would have made any difference.

Wow!
No galaxy is an island unto itself, with profuse apologies to John Donne.

Only thirty-five-million light-years away? A million light years diameter? 5.8 trillion miles across?! No wonder we can't tune in any of the inhabitants' radio stations.

Homunculus Caridae wrote:

BrianSherwood wrote:Seeing the proximity of these (and the third of the Leo Triplet) to each other, I wonder how our own sense of the universe would be different if we had nearby galaxies that would be so visible to the naked eye, and cover so much of the night sky. Would we be a little less self centered? Or would they have been just more 'splotches' like our own Milky Way?

We can see the sun and moon, a plethora of stars including the Magellanic Clouds, and solar planets yet we still evolved with an egocentric view of the universe. I'd be surprised if adding a big fat spiral galaxy or two to the view would have made any difference.

Funny thing. Last night 1AM I find out there's no toilet paper in the house. Cussing and grumbling I head out to our cars to scrounge around for tissues or something. Once outside I see it is a moonless night, unusually dark and I stare up and soak in the night sky, looking for planets and constellations. The melodrama of the moment subsides from center stage with the change in perspective.

I guess you could say that the sight of the night sky helped me become a little less self centered.

Pastorian wrote:
Last night 1AM I find out there's no toilet paper in the house. Cussing and grumbling I head out to our cars to scrounge around for tissues or something. Once outside I see it is a moonless night, unusually dark and I stare up and soak in the night sky, looking for planets and constellations. The melodrama of the moment subsides from center stage with the change in perspective.

I guess you could say that the sight of the night sky helped me become a little less self centered.

• What a moving experience

Callint earth Tower, this is M65 lead flight of two entering base on a 35 million mile final. Almost looks like a presentation flight. So cool

neufer wrote:What a moving experience

While the education gained from these forums is great, I come here for the non sequiturs.

The ancients looked at the sky as poets, not scientists. Or not !

Outstanding.