Object of the Week, November 13, 2022 - Hickson 98 (NGC 7783 & friends) in Pisces
R.A.: 23h54m10.1s
Dec.: +00°22'58"
Size: 1.5'x 0.7'; Magnitude: 14.0B

Deb & I had the pleasure of spending a week last month with Connie and Jimi Lowrey at their home in Fort Davis, Texas… and between the great meals and the great conversations we also managed to get in some observing… imagine that! Observing was limited by various combinations of wind, rain, humidity, and poor seeing/transparency, but we managed to accumulate about 12 hours of quality eyepiece time over 3 different nights and came away happy… but the weather difficulties allowed us more time to visit, always a good thing.

We logged quite a number of objects, both deep-sky stinkers and spectacular eye-candy objects, and a lot of stuff in between those extremes. Today’s OOTW is a typical example of the latter category.

HICKSON 98 area -Sloan.jpgHICKSON 98 LABELED 2.jpg

Hickson 98 was one of several HCGs that we observed but it was the only one that had thus far escaped being featured here in the OOTW, so the timing was great for me. It is a group of (4) galaxies in Pisces, with the anchor galaxy being NGC 7783, HCG 98A (aka Arp 323, VV 208), a spiral S0-a galaxy of about mag 14B. It was easily seen directly as a 2:1 smudge about 30 arcseconds long with a star on the SE end. Directly on the other side of the star is HGC 98B (PGC 72808, MCG+0-60-59) almost in-line with the main galaxy but aiming a little more south. This member is round and dim, about 20” or so in diameter, and stated to be about mag 15B. Continuing in generally the same direction for a little over an arcminute brings us to HCG C (PGC 72810), yet another mag dimmer at about 16.3B… but it too was fairly easy to observe with direct vision. Going back to NGC 7783 and heading a little east of due north about 40 arcseconds brings us to the last member of this cluster, HGC D (PGC 72803, MCG+0-60-60) and this stinker is still another mag dimmer at 17.5B! However, with averted vision and patience at the eyepiece, it was definitely detectable in moments of steady seeing. By the way, component “D” is actually a background galaxy and therefore not a physical member of the others.

In doing my due diligence about this object I ran across an interesting paper specifically about this group of galaxies, which can be accessed here…

As a bonus object, going back to HCG component C, about 23 arcseconds SW is another dim galaxy, this being Mac 2354+0021, mag 17B… and we could detect this guy, too, in moments of good seeing. We really enjoyed this observation.

As always, give it a go and let us know!