by Ann » Sun Feb 13, 2011 10:24 am
I'm fascinated by the picture of M109, NGC 3992. That blue star sitting right there in an inner spiral arm, displaying exactly the shade of blue that I expect from a type Ia supernova - could that be, indeed, a supernova? I checked out my "Color Atlas of Galaxies" by James D. Wray, from 1988, and the "supernova" was there in the same spot in M109 in Wray's UBG photo of the galaxy from 1979. So it is no supernova but a foreground star. Still, what an arresting picture!
The picture of M81 and Holmberg IX is unusually nice. It is an RGB image with displays an unusually rich palette of colors. The picture brings out, for example, how very blue Holmberg IX is compared with M81. The dwarf galaxy is very young and hence completely lacking in old yellow stars, but it is not "brand new" and therefore very deficient in red emission nebulae. However, some hints of purple can be seen in Holmberg IX, indicating, at least, the presence of very hot young stars still surrounded by gas.
Felipe Alvez image of M42 is beautifully detailed and richly and subtly colored. I think this may the first picture I have ever seen that brings out the color difference between the two brightest stars in the Running Man Nebula. The one on the left is an F0 star, with a color index of +0.269, and the one on the right is a more distant early B-type star with a color index of -0.183. That is a considerable difference in both spectral class and color index, and the two stars
should display different colors, but this is the first time that I've ever seen the star on the left look yellower than the star on the right.
Felipe Alvez has also taken a very, very beautiful picture of M35 and NGC 2158. The starry richness of the picture is wonderful, the two star cluster stand out against the background very beautifully, and the difference between the two clusters - the youth and relative nearness of M35 and the much greater distance, much greater age and considerably greater richness of NGC 2158, is beautifully brought out.
I also love the Pleaides and Moon picture. I don't think I've ever seen a picture where the Pleiades were seen close to the horizon, just above some treetops, looking huge.
Ann
I'm fascinated by the picture of M109, NGC 3992. That blue star sitting right there in an inner spiral arm, displaying exactly the shade of blue that I expect from a type Ia supernova - could that be, indeed, a supernova? I checked out my "Color Atlas of Galaxies" by James D. Wray, from 1988, and the "supernova" was there in the same spot in M109 in Wray's UBG photo of the galaxy from 1979. So it is no supernova but a foreground star. Still, what an arresting picture! :D
The picture of M81 and Holmberg IX is unusually nice. It is an RGB image with displays an unusually rich palette of colors. The picture brings out, for example, how very blue Holmberg IX is compared with M81. The dwarf galaxy is very young and hence completely lacking in old yellow stars, but it is not "brand new" and therefore very deficient in red emission nebulae. However, some hints of purple can be seen in Holmberg IX, indicating, at least, the presence of very hot young stars still surrounded by gas.
Felipe Alvez image of M42 is beautifully detailed and richly and subtly colored. I think this may the first picture I have ever seen that brings out the color difference between the two brightest stars in the Running Man Nebula. The one on the left is an F0 star, with a color index of +0.269, and the one on the right is a more distant early B-type star with a color index of -0.183. That is a considerable difference in both spectral class and color index, and the two stars [i]should[/i] display different colors, but this is the first time that I've ever seen the star on the left look yellower than the star on the right.
Felipe Alvez has also taken a very, very beautiful picture of M35 and NGC 2158. The starry richness of the picture is wonderful, the two star cluster stand out against the background very beautifully, and the difference between the two clusters - the youth and relative nearness of M35 and the much greater distance, much greater age and considerably greater richness of NGC 2158, is beautifully brought out.
I also love the Pleaides and Moon picture. I don't think I've ever seen a picture where the Pleiades were seen close to the horizon, just above some treetops, looking huge.
Ann