by NoelC » Fri Apr 13, 2007 5:19 pm
http://antwrp.gsfc.nasa.gov/apod/ap070413.html
Fantastic image!
I find it very interesting that in infrared light the dust in the region at the lower right of the APOD is shown to be hotter than the rest (assuming I'm not reading the color assignments backwards):
That same area is more reddish in deep exposures in visible light as well:
I had thought that perhaps the reddish color was ionized hydrogen gas, but it hadn't occurred to me that the area would be hotter as well.
I wonder, why is it hotter? It doesn't seem nearer the hot young stars than a lot of the rest of the nebula...
-Noel
http://antwrp.gsfc.nasa.gov/apod/ap070413.html
Fantastic image!
I find it very interesting that in infrared light the dust in the region at the lower right of the APOD is shown to be hotter than the rest (assuming I'm not reading the color assignments backwards):
[img]http://antwrp.gsfc.nasa.gov/apod/image/0704/m45_spitzerR720.jpg[/img]
That same area is more reddish in deep exposures in visible light as well:
[img]http://www.ourdarkskies.com/gallery2/d/1057-1/M45_Visible_Light.jpg[/img]
I had thought that perhaps the reddish color was ionized hydrogen gas, but it hadn't occurred to me that the area would be hotter as well.
I wonder, why is it hotter? It doesn't seem nearer the hot young stars than a lot of the rest of the nebula...
-Noel