4 Attachment(s)
Object of the Week, April 24, 2023 – SDSSJ0849+1114
Cancer
Triple galaxy merger
RA: 08 49 05
Dec: +11 14 51
Attachment 5106
(The image above is from a paper given by Ryan Pfeifle in 2019, titled “Uncovering Dual and Triple AGN’s in Galaxy Mergers”, which can be seen at: https://cxc.harvard.edu/symposium_20...an_pfeifle.pdf)
I’m pretty sure this is an object that Jimi turned me on to, so you know it’s awesome.
Located about a half degree south of the open cluster M67 is the faraway triple galaxy merger, SDSSJ0849+1114. I observed it almost exactly three years ago from my moderately light polluted backyard with my 28-inch f/4 scope. I had no thoughts of seeing the three galaxies individually, and only hoped to detect their combined glow – which I was able to do. What made this observation special is that the light travel time for these merging galaxies is 1.032 Gly – wow!
Just as amazing is that their co-moving radial distance – or how far away they are right now – is 1.072 Gly, which means the universe has expanded by about 40 Mly during the light travel time. So, this barely visible glow gave me the intellectual thrill of experiencing the expansion of the universe. Wow again!
The fact that I saw it from my backyard under a fairly normal sky for the location should mean that, under a dark and transparent sky, SDSSJ0489+1114 is accessible to much smaller scopes than my 28-inch. I can’t find a visual magnitude, but based on its appearance, I’ll guess it’s around 16th magnitude. Here are my observing notes and sketch:
“Billion-year-old / instantaneous light – I don’t think I’ll ever get used to this… Great way to start the evening, especially because this tiny, barely seen smutz isn’t even in the darkest part of the sky. I first saw it at 253x, but it was more difficult at 408x and 547x. 695x did the trick and I could see it about 50% of the time with averted vision – awesome! 20.23 SQM, April 16, 2020”
Attachment 5107 Attachment 5109
The DSS2 image below shows the three galaxies merging – something I had no hope of seeing from my backyard. But who knows, maybe the tidal arms from the merger can be detected under an excellent sky – so give it a go and let us know!
Attachment 5108
