When I look to the South at night, as I commonly do, I see the Southern Cross, and its 2 pointers, Alpha and Beta Centauri. I can’t actually identify the constellation of Centaurus — I’ve never got around to it, being somewhat transfixed by Crux.
What I see, of course, is a bunch of stars. Occasionally, on a particularly dark and clear night, I’ve just been able to make out the Clouds of Magellan — sort of, and maybe largely in my imagination.
But there’s a whole universe out there, much of it visible only at other wavelengths. If we could see radio waves, this composite photo shows how the galaxy Centaurus A would look in comparison to the full moon:
“If your eyes could see radio waves you would look up in the sky and see the radio glow from this galaxy covering an area 200 times bigger than the full Moon,” said the lead scientist for the project, Dr Ilana Feain of CSIRO’s Australia Telescope National Facility (ATNF).
Perhaps I should point out that the moon, full or otherwise, could never appear in that part of the sky … The image has been created to make a point.
Sometimes I can spend ohhh 15 minutes at a time editing photos I’ve taken. I think that’s a long time, but look how long it took them to create the photo above — 1200 hours just to capture the images:
Dr Feain and her team used CSIRO’s Australia Telescope Compact Array telescope near Narrabri, NSW, to observe the galaxy for more than 1200 hours, over several years.
This produced 406 individual images, which were ‘mosaiced’ together to make one large image. …
Processing the image — combining the data, taking out the effects of radio interference, and adjusting the dynamic range — took a further 10,000 hours.
10,000 hours of processing! I sure hope a lot of that was automated computerised work.
What a result — a stunning image. Next time I’m looking South, I’ll imagine I can see it.
Photo © Copyright CSIRO Australia, 7 July 2009: A composite image showing the size of the radio glow from the galaxy Centaurus A in comparison to the full Moon.