Palomar compact groups, interacting galaxies and a distant quasar

[Martin Meredith]

December has been a washout here until the last few days of settled high pressure, so last night under a bright moon and with temperatures falling to -4C I pointed the scope north to concentrate on a few square degrees in UMa in search of some weird and wonderful objects to end the year with.

What is it about flat galaxies that is so appealing? Here's an interacting group (from L to R: NGC 2820 and 2020A at its lower end, and NGC 2814; all at around 88 MLYs. These are part of the Vorontsov-Velyaminov catalogue of interacting galaxies, number VV1274. Also in shot at lower right is the face on spiral NGC 2805.

About a degree further south are a couple of very tight compact galaxy groups from the Palomar catalogue. The left hand circled group -- named by its RA/Dec coords 092831+634736 -- has 5 members in a radius of 0.3' with mags from 16.6 to 17.6. All are visible, with the 3 making a very tight equilateral triangle to the right. I haven't been able to find a distance estimate for this group.

The other group (092726+634929) does have a measured redshift of 0.143 (about 1.8 billion LYs). The 4 components vary from mag 16.8 to 18.6 and make up a trapezium. The faintest is just visible at the lower right of the circled area.

For lovers of compact groups, there are 543 listed in the combined Palomar catalogues, the most distant of which is at around 3.5 billion LYs.

Next, another V-V pair, 1401 (one of which looks stellar) interacting at 395 MLYs. Just below are a pair of faint galaxies and other mag 17-18 galaxies are in the shot. But for me the most interesting target is the quasar 4C 72.16 which with a redshift of 1.462 has a light travel time of 8 or 9 billion LYs...

Finally, here's a faint Abell galaxy cluster, 1124. Quite a few mag 17-19 galaxies are visible, particularly in the mid-low left, which surprised me given the presence of the moon. The brightest star in this shot is the Mira-type variable VX Uma which to my untrained eye looks near to maximum. I've attached a map showing the locations of some of these objects (stars plotted down to mag 18).

At this point it was so cold that the laptop battery refused to charge, so I called it a day and retreated indoors with my 3 coats.

Wishing you all an excellent 2015 and looking forward to seeing lots more feats of sensor/computer-assisted observing!

Martin

[Macavity]

This is video astronomy's great forte [imo]... Looking beyond the conventional.

Recently, I'd almost given up hope. The moon plus high clouds scattering light?

But, in the last few days, improvements - Glimpses down to Mag +17, +18... etc.

I love this stuff. Comparing observation with literature. Like "real science" man?

[Paul81]

Great stuff Martin!

I echo Chris's comment, this kind of astronomy would simply be impossible visually and EAA really allows us to branch out into the more 'advanced' astronomy previously unreachable. A lot of these galaxy groups are completely new to me, so each time I read the posts about them, or observe them myself I learn something new.

Hot on my list in 2015 is to try a transiting exoplanet observation!

[HiloDon]

Great job, Martin! I second Chris' and Paul's comments. EAA is making it possible to share our exploratory experiences. No one is going to be able to see everything that is out there, but together we can see a lot more.

Martin, you need to get yourself a portable ice fishing house like they use in Wisconsin to keep yourself and computer warm.

Have a great New Year!

Don

[nytecam]

Amazing deep deep DSOs Martin - let's be honest thesegxs are never going to be viewable through an EP - what extreme EAA is all about - keep it up

[Martin Meredith]

Thanks everyone! 

I must admit I enjoy trying to make the experience as much like eyepiece observing as possible, so a lot of things I look for are near the limit of detectability. You could say I've swapped faint fuzzies at the eyepiece for faint fuzzies on the screen (just that they're much more distant and perhaps 6 mags fainter).

For most of the objects nowadays I spend a lot of time star-hopping (I could enter the coords directly in the mount but I somehow prefer hopping from the nearest NGC/IC). That has the added benefit that initial alignment can be quite poor (and hence faster). With detailed maps covering say 4 square degrees its amazing just what is in the field or just around the corner, and appreciating the star patterns on the way to the object brings something of the Dobsonian push-to experience. Plus there's the excitement of eventually 'finding' the object, just as in non-GOTO visual. (And last time out I was reminded that typing at a frozen keyboard isn't so different from holding a frozen eyepiece or truss tube…)

After spending time with faint objects whenever I go back to larger objects I'm amazed by the details that can be picked up. Take the first shot (NGC2820) for instance. There's as much (more) detail in that mag 12.8 DSO than I've ever obtained in a large dob from M82 (mag 8.4). And the face on spiral NGC 2805 (mag 11) contains as much as I've teased out visually from say M33 (mag 5.7) in the past. Once you realise the entire NGC/IC catalogues are potentially open to that kind of detail it is a transformational experience.

Martin