Everyone knows the M13, Great Globular Cluster in Hercules. I like looking beyond the main target in a picture (which sometimes becomes a bit of an excuse) so I took a slightly longer exposure than necessary just for the cluster to see where else do the photons come from. Of course, we have NGC 2607 top-right, at about 30 million light-years. Still close.
Further and smaller, there are a number of PGC galaxies at hundreds of million of light years.
What I really wanted, though, are the quasars marked in magenta. In particular, the one at bottom left,
SDSS J163923.80+362019.9, has a redshift of 1.75 according to its
Simbad page. Using the calculator at
Ned Wright's Javascript Cosmology Calculator (and the instructions at
Converting Redshift to Distance – Remote Astrophotography Using Slooh.com), that translates into 12.993 Gly. OK, so about the
13 billion light years. That’s from when the universe was quite young and, of course, older than our solar system.
The other quasars are closer, at only a few billions of light years.
The image is a crop from a wider field and there were fainter quasars as well, but
SDSS J163923.80+362019.9 was well seen so I didn't annotate the others to avoid cluttering the image.
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