Observing Abell galaxy clusters at the Grand Canyon Star Party

by Jane Houston Jones

I'm working my way through the Astronomical League's /Observe Galaxy Groups and Cluste//rs/ project, so I printed out a bunch of Abell Galaxy Cluster (AGC) star charts using SkyTools http://www.skyhound.com/ software. I worked on the AGC's after the public star party hours at the Grand Canyon Star party June 26/27, 2003. Actually several of the clusters were bright enough to be part of my public star party telescope objects on those nights.

Early Abells - had to catch these early, so I showed them to the public!

AGC 1367 RA 11h 44m 30.0s Dec +19.50.00 Leo Galaxy Cluster near Denebola. Star party visitors could easily see the brightest of the galaxies here, NGC 3842 and NGC 3861 and sometimes a few more. I checked off 25 galaxies on my finder chart.

AGC 1631 RA 12h52m48.0s Dec -15.26.99 Corvus. 600 million LY distant. NGC 4756 (a foreground object), PGC 43730 and PGC 43777 seen easily by the visitors to the eyepiece. I checked off 11 galaxies on my finder chart.

AGC 1656 RA 12h 59m48.0s Dec +27.58.00 Coma Berenices. The famous Coma Cluster. Big and bright NGC 4874 and 4886 were easy for everyone to see. One park employee looked at it one night, then came back and pushed my 17.5-incher right to it again on another night, plus to nearby NGC 4565. He spent 4 nights with us, I think. Photographic memory! I checked off 11 galaxies on my finder chart this time around in the Coma Cluster. I was letting a few visitors use my telescope so I didn't want to hog it to myself all the time.

Later Abells - once the Grand Canyon Village bus nebula stopped circling the parking lot at 11:00 p.m.is when I got busy with projects.

AGC 1314 RA 11h 34m 48.0s Dec +49.02.00 Ursa Major. My favorite galaxy in this cluster is the Papillon Galaxy, 14th magnitude IC 708. I checked off 6 galaxies on my chart, including IC 712 and Markarian 178, a blue compact wolf-rayet dwarf galaxy. Nearby NGC 4449 and 4217 plus M94 were pleasant diversions.

AGC 1377 RA11h 47m 00.0 s Dec +55.44.00 Ursa Major. I checked off 6 galaxies in this cluster, including NGC 3850, 3888, 3913 and 3898.

AGC1318 RA 11h 36m 24.0s Dec +54.57.00 Ursa Major. One huge mag 12 galaxy, NGC 3733 was set next to a bright star, HD100615. This cluster is right in between Beta (Merak) and Gamma (Phecda) Ursa Majoris in the bowl of the big dipper. This one was a very low surface brightness galaxy, huge and looming at 333x. I think this was my favorite galaxy for a while anyway. I showed this to my new pal Susan, a college student park worker at the Hermit's Rest snack shop on the south rim of the Canyon. She spent 3 nights with us after she got off work, two nights on the 12.5 inch Strider, and one night on my 17.5-incher. :-) I checked off 5 galaxies on my chart.

AGC 1228 RA 11h 21m 30.0s Dec +34.19.00 Ursa Major. Those familiar with the 'three leaps of the gazelle" asterisms - aka bear paws on Ursa Major can follow me to AGC 1228. I spotted four galaxies in this cluster, IC 2751, 2744, 2738 and 2735 in a little line between the stars HD 98642 and Tyc 2522-1022-1.

AGC 1213 RA 11h 16m 30.0s Dec +29.15.00 Ursa Major. Close to AGC1228 on the other side of the gazelle leaps. Two tight cluster of galaxies seen. PGC 34393 and PGC 34385 seen too for a total of 6.

AGC 1185 RA 11h 10m48s Dec +28.40.00 Ursa Major. Good charts help here. This is right next to AGC 1213. Nice pair of galaxy pairs -- NGC 3552 and PGC 1843154 and NGC 3554 and PGC 1842212 helped to assure I was looking at the right cluster here. Other pairs of galaxies in the cluster are NGC 3558 and PGC 1838864 and PGC33931 and 1832356. Other notable galaxies here are NGC 3561 (ARP 105) and the brightest of all is mag 14.1 NGC 3550. This is a good one to try, with lots of goodies to be seen. I checked off 12 galaxies in this cluster.

On to Hercules overhead. ACG 2152 RA 16h 05m 24.0s Dec +16.26.00 Hercules. There are three Abell clusters between Gamma Serpentis and Gamma Herculis. The first I observed is AGC 2152 RA 16h 05m 24.0s Dec +16.26.00 Hercules. I spotted five of the members, a straight line of galaxies PGC 57177, 57067/68 and PGC 57004, plus a little edge on PGC 57093.

AGC 2151 RA 16h 05m 12.0s Dec +17.44.00 Hercules. I spotted quite a few of the galaxies in this cluster. I actually looked at several of the Hercules galaxy clusters on two consecutive nights. Lots of mag 13 and 14 galaxies here. I checked off 15 galaxies in this group over the 2 observations. Chains of galaxies and galaxy groupings make it an especially nice find. NGC 6039, 40, 41, 42 made up one little group. NGC 6043, 45 and 47 another, and IC 1182, 83 and 85 yet another group -- all near the center.

AGC 2147 RA 16h 02m 18.0 sec Dec +15.53.00 Hercules. Arp 324, a magnitude 14.3 galaxy is the brightest here and part of a nice little chain of galaxies. I checked off 4 galaxies in this group.

AGC 2197 RA 16h 28m 12.0s Dec +40.54.00 Hercules. Easy starhop from M13 or Eta Herculis, or both. I was tired of standing on a short ladder (all we could pack in the van) looking up high. I checked off only 4 of the many galaxies on my chart, including NGC 6160, 6173 6175, 6146 and PGC 58193.

AGC 2199 RA 16h 28m 36.6s Dec +39.31.00 Hercules. Mag 12 galaxy 6166 dominates the field here. I was running out of steam and just took a quick look here.

ObserverJane Houston Jones
DateJune 26/27/28, 2003
LocationYavapai Point, Grand Canyon National Park 36 04' 12" N , 112 degrees 07' 12" W Altitude 7040 ft.
Instruments17.5-inch f/4.5 Litebox reflector, Orion 80mm reflector used as a finderscope, Telrad
Oculars6mm Radian (333x), 9mm (222x) and 16mm (125x) Naglers in Litebox 17.5-inch. 25mm (16x) Kellner with cross-hair in 80mm Orion short tube finder
Seeinggood. Humidity less than 20 percent all week
TransparencyLM 6.0 to 6.6 using LM Area 16. Best straight overhead and north. South wrecked at times later in the week.