by Ann » Sat Mar 23, 2013 6:47 am
Boomer12k, I never look at astroimages that way! But I like it. I can barely spot your Anime Cat Lady Pirate, but I think I can really see a cat at nine o'clock in this image. Its head is outstretched to the left and held sideways. We can see its eyes and some white above its eyes, and I think I can spot its ears, too. And at about five o'clock I can see a big, dark wolf. I can see its open jaws, two large, misshapen ears, and one, perhaps two, glowing white eyes!
What I really see when I look at a picture like this, however, is how round the Large Magellanic Cloud really is. In visual light, it is so easy to focus on the prominent bar of the LMC and of course on the magnificent Tarantula Nebula. Spiral and irregular galaxies easily look like bright non-spherical structures with a lot of emptiness between the bright parts:
But the empty parts are not empty, just not very luminous. Today's APOD brings out all the non-luminous dust that permeates the large conglomerate of dark and baryonic matter that is the Large Magellanic Cloud. The bright and brilliant stars and nebulae are really just like foam on a large, deep sea.
One thing we can't see in today's APOD is the prominent bar of the LMC. Galactic bars are typically made up of old or at least intermediate stars, and there is usually little dust in the bar. A typical feature of barred galaxies, however, is an enhanced rate of star formation at or near the ends of the bar. The incredible star cluster R136 and the fantastic Tarantula Nebula are perfect examples of enhanced star formation near one end of a galactic bar, and the Tarantula Nebula region does indeed show up well in the infrared picture. Gas and dust are being funneled to the end of the bar, where it accumulates, leading to enhanced star formation. This dust shows up well in infrared images. But the star formation in itself also creates dust, making regions of star formation very dusty and easy to spot in infrared images.
Ann
Boomer12k, I never look at astroimages that way! But I like it. I can barely spot your Anime Cat Lady Pirate, but I think I can really see a cat at nine o'clock in this image. Its head is outstretched to the left and held sideways. We can see its eyes and some white above its eyes, and I think I can spot its ears, too. And at about five o'clock I can see a big, dark wolf. I can see its open jaws, two large, misshapen ears, and one, perhaps two, glowing white eyes!
What I really see when I look at a picture like this, however, is how round the Large Magellanic Cloud really is. In visual light, it is so easy to focus on the prominent bar of the LMC and of course on the magnificent Tarantula Nebula. Spiral and irregular galaxies easily look like bright non-spherical structures with a lot of emptiness between the bright parts: [img]http://www.seasky.org/celestial-objects/assets/images/galaxy12.gif[/img]
But the empty parts are not empty, just not very luminous. Today's APOD brings out all the non-luminous dust that permeates the large conglomerate of dark and baryonic matter that is the Large Magellanic Cloud. The bright and brilliant stars and nebulae are really just like foam on a large, deep sea.
One thing we can't see in today's APOD is the prominent bar of the LMC. Galactic bars are typically made up of old or at least intermediate stars, and there is usually little dust in the bar. A typical feature of barred galaxies, however, is an enhanced rate of star formation at or near the ends of the bar. The incredible star cluster R136 and the fantastic Tarantula Nebula are perfect examples of enhanced star formation near one end of a galactic bar, and the Tarantula Nebula region does indeed show up well in the infrared picture. Gas and dust are being funneled to the end of the bar, where it accumulates, leading to enhanced star formation. This dust shows up well in infrared images. But the star formation in itself also creates dust, making regions of star formation very dusty and easy to spot in infrared images.
Ann