By David Pescovitz at 11:44 am Thu, Sep 20, 2012
This is M51, the "Whirlpool Galaxy." The image is by Martin Pugh who won the Royal Observatory Greenwich's Astronomy Photographer of the Year 2012.
I’m working with M51, also known as NGC5194/5, which gives me a different view of the galaxy, black and white sadly. I have a .ps file with various graphs of the infrared flux (in the 3.6, 4.5, 5.0, and 8.0 micron wavelength) at various apertures. If anyone is interested in seeing it I’d gladly upload, but what’s the best way to distibute a 5 mb .ps file?
save as… jpeg
tiff in a tarball. I’d love to pick through that. My wife brings home TEM imagery, and I enjoy seeing those too.
Re: “black and white, sadly” — all images are basically black and white. There’s only minor chromatic variation in stellar output across star types. This pic and all the other “wow” Hubble pix are false-color to enhance our viewing pleasure. (and occasionally to aid in distinguishing visible from IR from radio waves, etc.)
sorry – wrong. the image of the galaxy above is LRGB, taken thru 4 filters, luminance, red, green, and blue. it’s not false color.
the false-color hubble pictures are narrowband pictures, taken with the 3 common narrowband filters which pick up the red light from 1) the hydrogen-alpha transition, 2) the sulfur-2 transition (also red) and 3) the oxygen-iii transition (kind of a blue-green color) because SII and Ha would be the same color to the human eye (if we could see them – extremely deep red), SII is mapped to the red channel, Ha to green, and OIII to blue.
if you could see that galaxy with your own eyes, it would look very much like the picture above.
source: i am myself an amateur astrophotographer.
most serious astrophotographs are taken with black and white cameras with the above-mentioned filters in front of the sensor. each filter is exposed separately for several hours, but cut up into 5-10 minute exposures and stacked. then the channels are combined to RGB images. when you use RGB filters, you see what the eye would see.
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