Thursday 8 September 2011

29.8.2011 - Two Trees with bats and bunnies

Date: 29./30.8.2011
Observing location: Two Trees, Cottonwood, Arizona, USA (1194 meters / 3917 feet)
NE Lim.mag: 7.5m (zenith)
SQM-L: 21.55 (zenith)
Background sky: 8 (excellent)
Seeing: 8 (excellent)
Transparency: 8 (excellent)
Weather: +27.9 - 24.4°C, humidity 28%, thunderstorm in the north.

Light domes of Prescott and Cottonwood
This was a beautiful place to spend the night. Not only had it dark skies but the amount of wildlife was staggering (plenty of bats and bunnies and an owl were some of the things seen) to a point I actually felt almost like observing back in Finland. Two Trees is the dark sky observing site of Astronomers of Verde Valley and it lies between Sedona and Cottonwood - only a 15 minute drive away from the hotel. A big thank you goes to JD Maddy, who was kind enough to direct me to this site as well as several others in the area. What might be lost at being at a slightly lower altitude is surely gained back in darker skies and lack of stray lights. From the site, light domes of Prescott, Cottonwood, Flagstaff and Sedona were visible but not very high or in crucial positions. When I arrived at the site a thunderstorm (4th of the trip) putting up a beautiful display in the northern sky and lasted for hours.

Observing here was wild to a point when I not only heard gunshots in the distance but got bitten on my left ankle by some... thing (and it still is missing a small piece). The gunshots were that of a hunting party, apparently hunting deer (saw a dead one with a bunch of guys standing next to it with rifles) and it got me thinking what chance do I have against these gunmen? Tired, long beard and dressed all in black, could I actually be mistaken as a deer in complete darkness? Luckily, I didn't have to find out as I never saw these guys again. And the thing that "bit me" might have just been a shrub or something with spikes. At least I'm not dead yet. Sadly, I failed to see any real spiders or scorpions on my trip.

So, great skies and what do I do? I sketch the open cluster NGC 6231, an object that of course could not be sketched from say Palm Springs or anything with suburban skies? Apparently not. Taking my time rendering the cluster properly, I moved up a bit to emission nebula NGC 6334 which - with UHC filter - showed 5 separate patches of nebulosity with different sizes. Another great one, although faint, was NGC 6357 (which I nicknames "The bird and the dragonfly" back in 2003) a bit more to the north. This one appeared quite similar to NGC 6334 but a lot smaller and fainter with an O-III filter. The small open cluster Pismis 24 was just south of the brightest, E-W small elongated patch of nebulosity that is the brightest part of the whole complex. Still moving back up north, I had set my sights on Sh2-13. See, NGC 6231 is forgiven after a couple of "hardcore" objects that I had specifically saved for dark skies. I noted some patchiness here too with the UHC filter but it remained uncertain if it was simply glow of the background star cloud.

The session took a darker path when Barnard 87 drifted to the eyepiece. Having the nickname of "Parrot's Head Nebula" I have to admit it looked a bit like it. Next heading close to the horizon I picked up NGC 6723. This is a great region for photographers and visual observers alike. In the same field of view you can see a reflection nebula, emission nebula, globular cluster and a dark nebula. So if in this region of sky - do not miss this posse! If you're sketcher like me... you better avoid this region like the plague. There's just so much to see and draw... After one tough nebulous cookie, I routinely logged Terzan 7 and despite the low altitude, I had only little trouble logging this 12th magnitude globular cluster. The final object of the night was NGC 6717 displaying small grouping of bright foreground stars with a fairly bright background glow.