Donal wrote:



I'm astonished at how little light pollution
you have. I thought that you lived near NY????

Here is a photo of the same object that I took recently.
http://www.astroimaging.org.uk/tener.../donal/M31.htm

It isn't great, but it is only 36m exposure. I'll try to get
more on it if the sky ever clears.


Very impressive. I never get a sky like that near Boston. However,
here's a picture of the same object I took from a higher perspective.

http://mix.msfc.nasa.gov/IMAGES/MEDIUM/8000105.jpg

OK, I was not the lead scientist, but almost all of the data processing
software, from decoding the telemetry to putting the picture on the
display was written by me, and I was at the keyboard when the NASA
photographer took this picture of the screen. In '78 color displays
were so uncommon that we didn't pass around picture files, we
photographed the screen, usually with Polaroids, but 35mm for
publication. Each little red dot is actually one x-ray photon, focused
by a "grazing incidence mirror system." Magic! This picture was one of
the first we got of a nearby galaxy showing individual x-ray sources,
so it caused quite a stir.

More on the pic:
http://mix.msfc.nasa.gov/abstracts.php?p=1560

and instrument:
http://heasarc.gsfc.nasa.gov/docs/ei...ao2_about.html