Wednesday, 7 September 2011

28.8 - 1.9.2011 - Sedona and the light pollution ordinance (Part 1)

Date: 28./29.8.2011
Observing location: Sedona, Arizona, USA (1368 meters / 4488 feet)
NE Lim.mag: 6.9m (zenith)
SQM-L: 21.10 (zenith)
Background sky: 7 (good)
Seeing: 7 (good)
Transparency: 7 (good)
Weather: +28.5 - 25.6°C, humidity 36%, 4/8 scattered cloud early on.

Honestly impressed...
After an off-night in Las Vegas, our travelling party arrived to Sedona, Arizona. That night I had planned on doing some simple bright object work from the hotel premises. I was aware of the Northern Arizona lighting codes but boy was it different than I though. Anyone who has participated in forcing this law down the public's throat should be given a medal or no, the Nobel price (despite being Swedish...). Based on the effects it had in downtown Sedona, this kind of law should be made mandatory in every corner of the civilized world. Then again, I understand the fear of the dark by the city dwellers who haven't even seen a dark sky or darkness in their lifetime. While observing in Sedona for 5 nights, I can honestly say I heard at least a dozen hotel guests whining about the darkness and saying they're going to go to the receptionist and complain about the hotel being so badly lit at night. Honestly, if you even can't enjoy a piece of the ever fading beauty of a dark night sky... you better not leave your apartment in Manhattan. Here, you might even see a bird, falcon or even more frighteningly a spider! Being a typical Finnish keep-your-mouth-shut-at-all-times-type there were quite a few times I almost yelled at these people from the balcony. I also managed to eavesdrop (not by purpose) on a mother telling her daughter about the stars in the sky and especially regarding the Big Dipper. She told her daughter that no matter where you travel, the Big Dipper always looks the same.

Anyway, imagine my surprise when after sitting in a car for the whole day, exhausted and miserable, I walked to our hotel room's balcony for a quick gaze of the sky and could easily see the Milky Way stretching across the entire sky. I went directly back in and fetched my SQM-L meter - safe to say I was impressed. It wasn't long before I was observing in "full force". The sky was dark enough and all the goodies in life (fridge and bed) were so close by that I decided to do most of the observing from the hotel's balcony shielded by several, large bath towels.

Cederblad 211 around R Aquarii
I continued where I had left off in Death Valley: Sagittarius-Scutum region of the sky. I observed a couple of planetary nebulae including NGC 6751, IC 4846, IC 4732, NGC 6565 and NGC 6629. Globular clusters ESO 456-38 and NGC 6540 (displaying a W-E elongated bar of stars in the middle) were both easily picked up by the 4.5 XT. Especially beautiful was the dark nebula Barnard 90 and a curious (possible) addition to my list of objects observed later on in the early morning was Cederblad 211 in Aquarius. I felt that the nebula didn't quite rise high enough for a proper gaze. I tried different magnifications, filters but at least for me the best view came unfiltered at high magnification (304x). I saw a very faint envelope around the star with some possible extensions (or diffraction spikes?) towards the N and S but it remained uncertain if this was just a general glow of the star or something else. In any case, the possible features in this object are very tiny - just some arc seconds.

Date: 30./31.8.2011
Observing location: Sedona, Arizona, USA (1368 meters / 4488 feet)
NE Lim.mag: 6.7m (south)
SQM-L: 20.84 (south)
Background sky: 7 (good)
Seeing: 7 (good)
Transparency: 7 (good)
Weather: +23.0°C, humidity 32-45%, clear.

Having spent the previous night (29-30.8.2011) at a darker location - Two Trees - I still wasn't done with observing, not by a long shot. It is not too difficult to guess where I started observing: Scorpius. Low from the sky, I could just observe globular clusters NGC 6380 (magnitude 11.5) and Tonantzintla 2 (magnitude 12.2). Despite the faintness, it wasn't surprising I saw this pair - I've managed to squint down both some years ago even with the small 3 inch refractor! Good objects during the night included two detailed planetary nebulae: NGC 6563 and NGC 6445. Of a handful of globular clusters most memorable were Palomar 8 (quite easily visible with averted vision) and NGC 288 which showed three "star spikes" and was fairly well resolved.

No complaints about the scenery either...
I also took a great deal of time to make sure I sketch at least some Messier objects with "care and respect". Having basically dropped all brighter globular clusters from my sketching list for "practical reasons" I probably should have done the same with a number of objects such as M16, M17 and M8. It literally took hours on several different nights for me to complete these "simple" 3 sketches. Without a doubt, M8 is the best nebula out in the sky - nothing even comes close. Then again, I haven't yet seen NGC 3372 but at least compared to M42... the "Nebula of the Black Lagoon" wins - hands down. It actually took me 3 separate nights (in Death Valley, Sedona and Two Trees) to finish up a simple sketch of M8.

Early in the morning I did some work with galaxies (see Iiro, I DO observe galaxies from time to time) with NGC 7606, NGC 7600 and NGC 7585. I could also pick up IC 1613 and the Sculptor Dwarf (ESO 351-30) while near their culmination points. NGC 253 was beautiful as was NGC 247 but I'm hoping I'll get to sketch these again from a more southern location (namely Tenerife) in few months.

Pleiades / M45
Probably the most memorable view of the night was that of the Pleiades. As it was racing high in the sky I pointed my telescope at it. NGC 1435 (Merope nebula) was a distinct direct eye object as well as visible in the 6x30 finder. NGC 1432 (Maya nebula) was plainly visible but in this case required some averted vision. The easy way to tell the difference between real nebulae and reflections is of course the fact that none of the nebulae observed looked symmetrical (or round) but irregular and had even spots of uneven brightness! Also, with higher magnification, several "spikes" were seen following the nebulosities surrounding Maia, Merope and Elektra. Atlas and Pleione seemed to be clear of nebulosity. I can't remember the last time I had such a clear view of the Pleiades - a big thank you to Arizona's low humidity.