Object of the Week, August 21, 2022 - ACO 3744 - CAPRICORN
Object of the Week, August 21, 2022 - ACO 3744 - CAPRICORN
R.A.: 21h07m12.0s
Dec.: -25°28'00"
The Abell galaxy cluster ACO 3744 is in southern Capricorn, near the bottom apex of the huge Bikini Bottom asterism. The 3 major components of the cluster are NGC 7016, NGC 7017, and NGC 7018. A slightly dimmer galaxy is nearby, PGC 66149 (MCG -4-49-16), and this completes the main group. There are lots of other galaxies swarming in the background but most are beyond the reach of my telescope.
I’ve observed this group a couple of times over the years but I never really spent a lot of time studying it, I was only interested at the time in counting as many of the mostly dim cluster members as I could. The last time I looked, a few years ago, the seeing and transparency were particularly good in my local desert observing spot and I pumped up the power a bit to see what I could see. Whoa, NGC 7018 is quite elongated and suddenly becomes an obvious pair, with one of them being slightly brighter than the other! But wait, there’s more! NGC 7017 is also elongated… but I never could split them up.
So, off to Google I go, to learn more about this cluster. It turns out that NGC 7016 and NGC 7018, both elliptical galaxies, are also bright radio galaxies near the center of the cluster, as described in this paper…
Reply With Quote