Willow Springs 6/7/08

Steve Gottlieb

Mark Wagner and Greg Laflamme have beat me to the punch with excellent ORs from last Saturday at Willow Springs, but I'll add a few of the evening's targets to the mix. As both Mark and Greg indicated, sky conditions were very good -- my new SQM-L (http:// unihedron.com/projects/sqm-l/) which measures light in a much smaller 10 degree cone, was reading between 21.57 and 21.63. But seeing was generally soft, particularly early on and the transparency was off a bit from excellent nights at this site. We shared views through our scopes during the evening and took regular climbs up the imposing ladder of Kevin Ritschel's 33" f/5 as he quickly swung around the sky with his huge scope and found a number of interesting deep sky objects.

Before starting to observe we were treated to an excellent view of the ISS and docked Shuttle Discovery at 9:15 as it swept across the sky from NW to E. Then while the moon was up I went after some doubles stars down in southern Lupus after I noticed Omega Centauri was visible naked-eye low in the south. The southern horizon is very good at Willow Springs, though Kevin's house blocks the view to the southwest. I was surprised I was easily able to pick up h4690 (discovered by John Herschel). This is a "wide" 19" pair of mag 5.5/7.7 stars with an orange primary, resolvable in any scope. But at -46 degrees dec, it scoots just a couple of degrees over the top of the mountain ridge to the south. My favorite Lupus double was Xi, a striking 10" pair of mag 5.2/5.6 stars (visible naked-eye).

While I was in the vicinity, I also took a look at NGC 6026, a fairly faint planetary surrounding a mag 13.5 star. I first took a look in Ritschel's 33" and the central star dominated the view. With my 18" Starmaster, the NPB filter increased the contrast and highlighted a moderately bright disc.

As the moon started to set, I took my last look for this year at a few spring galaxies including the interacting pair, NGC 4490 and 4485, which Kevin was showing off in the 33". The NW "arm" of NGC 4490 is tidally disturbed by its smaller companion and a tail of material connects the galaxies. As an experiment, I compared views in the 33" (connecting arm easy and structure visible within NGC 4490 and NGC 4485), my 18" Starmaster (the disturbed arm on the WNW end extending towards N4490 was easily visible) and my 15x50 Canon IS binoculars (just a single faint blur, of course).

NGC 5248 is the brightest galaxy in Bootes and shows off two spiral arms in larger scopes. After soaking in the view in the 33", I logged these notes in my 18" --
"Bright, large, elongated NW-SE, 3.5'x2.4', sharply concentrated with a very bright, round 25" core. At 200x, two spiral arms extend out from the central region, the brightest and longest is attached at the east side of the core and gradually sweeps to the north. A couple of very faint, very small knots are embedded in this arm including one due west of the core. On the east end of the core a matching arm is attached that curves a bit more as it swings towards the south in a counter clockwise orientation. A faint star is just north of the central region and a brighter star is 1.7' S of center."

Although I've showed off the famous double star Mizar in the handle of the Big Dipper a bazillion times at star parties, I didn't realize a faint galaxy shared the same field! MCG +09-22-053 resides just 13' SW of Mizar in the same low power field. At 200x and 262x it appeared as just a faint, very small, round glow of 18" diameter located 50" SSE of a mag 11 star. I'm surprised this galaxy is not a well-known challenge object -- it's certainly easier than the faint galaxies near M57 (IC 1296) and M13 (IC 4617). Ritschel mentioned this object to me at an April star party.

Mark was taking a look at Hickson 82 in Hercules (3 NGC's and one faint member). These 4 small galaxies form a near perfect parallelogram with sides 3' x 1'. The only "challenge" is tiny HCG 82D -- the total blue magnitude is catalogued as only 16.7 and I logged it as an extremely faint and small knot, just 5" in diameter. But Greg pulled it in quickly with his 15". Can it be seen in a 10" or 12"?

Next up was a group of galaxies near M13. NGC 6196 is the middle and brightest of a trio on a line. At 260x it appeared fairly faint, fairly small, slightly elongated, sharply concentrated with a bright, 20" core that increased to a stellar nucleus with direct vision and a 35"x25" halo. IC 4614 lies 3' NNW and NGC 6197 is 5' SSE. Other nearby galaxies included CGCG 196-081, CGCG 196-084, UGC 10473 and KUG 1635+360. This group of galaxies is located about 50' WSW of M13!

Later in the evening, Mark and I took a close look at the interesting pair, IC 1258 and IC 1259, in Draco. Observe this field and you've nabbed two Arps (310 and 311) for the price of one. The more interesting member was IC 1259. At 260x this double system (Arp 311) appeared faint, very small, ~20" diameter, quasi-stellar nucleus. An extremely small companion, ~10" diameter, was barely resolved off the west edge of the brighter eastern component. IC 1259 forms a close pair with IC 1258 (Arp 310) just 2.2' SW. All in all, a very enjoyable evening with great views and friendly company.

Steve