by RJN » Sun Feb 21, 2010 6:01 pm
biddie67,
Thanks for your good questions. "Black body" is a technical term and doesn't necessarily mean the object appears black. The term means that the object doesn't reflect any light and glows only because is it hot. As the object cools, it glows less and less. Eventually it will appear black. A cooling white dwarf can be considered a "black body" in the sense of the technical term.
The false colors were chosen by a member or members of the Hubble Heritage Team, a group of astronomers who take old and archived Hubble images, find the raw photographs taken separately in different colors, and combine those images into one usually spectacular image. Now they can choose different images to combine, and use a Photoshop type program to make different colors more prominent. I believe the color processing on NGC 2440 was done by Forrest Hamilton, who is linked near the end of the APOD text. To find a different mix of colors, click the link "above cocoon" in the APOD text. Personally, I liked Forest's mix the best, and so I chose that one for this APOD. BTW, many times the word "above" in the APOD text is linked to the original image location on the web.
I hope this is a help! - RJN
biddie67,
Thanks for your good questions. "Black body" is a technical term and doesn't necessarily mean the object appears black. The term means that the object doesn't reflect any light and glows only because is it hot. As the object cools, it glows less and less. Eventually it will appear black. A cooling white dwarf can be considered a "black body" in the sense of the technical term.
The false colors were chosen by a member or members of the Hubble Heritage Team, a group of astronomers who take old and archived Hubble images, find the raw photographs taken separately in different colors, and combine those images into one usually spectacular image. Now they can choose different images to combine, and use a Photoshop type program to make different colors more prominent. I believe the color processing on NGC 2440 was done by Forrest Hamilton, who is linked near the end of the APOD text. To find a different mix of colors, click the link "above cocoon" in the APOD text. Personally, I liked Forest's mix the best, and so I chose that one for this APOD. BTW, many times the word "above" in the APOD text is linked to the original image location on the web.
I hope this is a help! - RJN