Sketching wise the 2.5 half week trip was quite productive. Mistakes were made but also some intentional ones: I deliberately left many, many objects east of Sagittarius to finish on a later date. This can be observed from a more southerly location in the end of November if the weather cooperates. In total, I managed to sketch 135 objects in 11 nights (~12 sketches / night) and in my defence many of these were quite simple open clusters.
Only a couple of asterisms were noted during the sweeps:
HD 152521-group
A group of 40* between magnitudes 6-11 within 25'.
HD 174919-group
A scattered grouping of stars just north of NGC 6716. 40* between magnitudes 7-11. Size 30'.
HD 173837-group
A small concentration of 20 stars between mags 9-12. Elongated in N-S direction.
HD 172948-group
A small concentration of 30* within 20'. Center without stars.
HD 159764-group (ASCC 90)
Concentration of stars NE from NGC 6396. 20* within 30'. Several stars brighter than 11th magnitude. Rediscovery of ASCC 90.
HD 162016
Barely NW from Messier 7. A handful of bright stars within 10'.
TYC 7378-1461-1
S of NGC 6480. V-shaped asterism of 30* within 15' between magnitudes 10-12.
All and all a great trip with beautiful scenery, a lot of driving and exhaustingly long flights. Hopefully I'll get to return to the US sometime in the future for some more star gazing. Regarding the sketches, please be patient. It will take several weeks if not months to finish them all in midst of work, my studies and general laziness. As with the previous La Palma trip, I've added a page showing all sketches made during the trip and will update them as soon as I get the drawings finished and scanned up.
Thursday, 8 September 2011
28.8 - 1.9.2011 - Sedona and the light pollution ordinance (Part 2)
Date: 31.8/1.9.2011
Observing location: Sedona, Arizona, USA (1368 meters / 4488 feet)
NE Lim.mag: 7.0m (zenith)
SQM-L: 21.00 (zenith)
Background sky: 7 (good)
Seeing: 7 (good)
Transparency: 7 (good)
Weather: +26.0 - 21.0°C, humidity 28%, clear.
I had a mix of some interesting objects for the almost last night of the trip. I had forgotten all about IC 4628 in Scorpius so I started it that and the nebula wasn't difficult to spot as an E-W elongated puff in a rich field of stars. I also humbled to sketch the large cluster Collinder 316, pretty much sketching everything I could see with the 40mm eyepiece (98' fov). Looking at the area after the fact, it seems like a big mess. Uranometria shows Cr 316 as a superimposed cluster surrounding Trumpler 24 with smaller clusters vdB-Ha 205 and Ruprecht 122 inside it. My SkyMap (updated cluster data of Dias et al.) shows vdB-Ha 205 with somewhat curious name of BH 205 and Ruprecht 122 as BH 202. It also includes three(!) additional clusters inside Collinder 316: ESO 332-08 (which I noted as a concentration of Cr 316), ESO 332-11 and ESO 332-13! Quick clean up is in order so vdB-Ha 202 = Ruprecht 122 (1975 vs 1967 discoveries respectively) and the ESO clusters are probable cluster candidates. And Uranometria was right, no surprise there.
After all that, I was finally able to see the three open clusters that had eluded me on previous two attempts. The reason was obvious: I was looking for something far more brighter and obvious. These clusters, located just SW of Messier 8, are marked in Uranometria (Volume 2 / Chart 146) as Ruprecht 138, 138 and 169. However Ruprecht 138 = NGC 6506! There is a 4th grouping of stars in this area but it is merely an asterism (noted by Phillip Teutsch). SkyMap's cluster data shows Ruprecht 137 near by - just south of HD 164147 but there is no cluster here. It is located more to the south roughly at 18 00 17 -25 14 00. Luckily, MegaStar correctly lists the whole bunch.
Next in line was supposedly one tough trio: two Terzan globular clusters and a Palomar. I began with Terzan 10 as it was close enough to the previous clusters. I routinely sketched the field and with averted vision could a few times saw a very faint, tiny nebulous patch just NW from a roughly 12th magnitude star and I marked this as Terzan 10. Wait, back up! Is this the same globular cluster Barbara Wilson has failed to see with a 20 inch telescope? Yes, the very same. Then, is there even a remote possibility that I actually saw it from a location such as Sedona and with an 4 inch aperture? I'm not going to say I saw it just based on this single observation but I'm going to give you a few things to chew on:
1.) I sketched the cluster perfectly to the correct position @ 304x
2.) There apparently a very faint pair (~15th magnitude) of stars just in front of Terzan 10.
3.) Terzan 10 is placed way off in SkyMap (surprised, anyone?).
With Terzan 10 in the (iffy) bag I moved to Terzan 5 which I can honestly say I saw. With such small aperture the field was dangerous none the less: I picked up 2 additional glows in the field when using low power. The most obvious is an asterism (Asterism 1 - I'm calling it the "Fake Terzan 5 group") of 8 stars between magnitudes 11.3 - 13.9 and it looked too good to be true and higher power showed it just as a group of stars. The other one was a group of 4 stars including a magnitude 11.7 and 11.9 double (Asterism 2). This too looked nebulous at lower power. Terzan 5 actually forms a triangle with these two and was seen as a very faint, very small glow just W of a 11th magnitude star.
And then came Palomar 6 (by the way, this globular cluster includes the planetary nebula JaFu 1 in case you didn't remember). Despite its apparent faintness (if you can call it that) it was easier to see than Terzan 5 and appeared as a faint, round smudge in a rich star field with dark nebulae. After a success with Palomar 6 I went on to sketch Palomar 11 - again. Then I got back to even more familiar territory with open cluster NGC 6604 which I saw more of a large cluster with two concentrations than the tiny 5' cluster listed as NGC 6604. I really took a liking with this field which includes the emission nebula Sh2-54 in the background. NGC 6818 showed a definitive ring structure and Messier 75 two "bars" extending from the bright core.
Observing location: Sedona, Arizona, USA (1368 meters / 4488 feet)
NE Lim.mag: 7.0m (zenith)
SQM-L: 21.00 (zenith)
Background sky: 7 (good)
Seeing: 7 (good)
Transparency: 7 (good)
Weather: +26.0 - 21.0°C, humidity 28%, clear.
I had a mix of some interesting objects for the almost last night of the trip. I had forgotten all about IC 4628 in Scorpius so I started it that and the nebula wasn't difficult to spot as an E-W elongated puff in a rich field of stars. I also humbled to sketch the large cluster Collinder 316, pretty much sketching everything I could see with the 40mm eyepiece (98' fov). Looking at the area after the fact, it seems like a big mess. Uranometria shows Cr 316 as a superimposed cluster surrounding Trumpler 24 with smaller clusters vdB-Ha 205 and Ruprecht 122 inside it. My SkyMap (updated cluster data of Dias et al.) shows vdB-Ha 205 with somewhat curious name of BH 205 and Ruprecht 122 as BH 202. It also includes three(!) additional clusters inside Collinder 316: ESO 332-08 (which I noted as a concentration of Cr 316), ESO 332-11 and ESO 332-13! Quick clean up is in order so vdB-Ha 202 = Ruprecht 122 (1975 vs 1967 discoveries respectively) and the ESO clusters are probable cluster candidates. And Uranometria was right, no surprise there.
 |
| NGC 6506 field |
Next in line was supposedly one tough trio: two Terzan globular clusters and a Palomar. I began with Terzan 10 as it was close enough to the previous clusters. I routinely sketched the field and with averted vision could a few times saw a very faint, tiny nebulous patch just NW from a roughly 12th magnitude star and I marked this as Terzan 10. Wait, back up! Is this the same globular cluster Barbara Wilson has failed to see with a 20 inch telescope? Yes, the very same. Then, is there even a remote possibility that I actually saw it from a location such as Sedona and with an 4 inch aperture? I'm not going to say I saw it just based on this single observation but I'm going to give you a few things to chew on:
1.) I sketched the cluster perfectly to the correct position @ 304x
2.) There apparently a very faint pair (~15th magnitude) of stars just in front of Terzan 10.
3.) Terzan 10 is placed way off in SkyMap (surprised, anyone?).
 |
| Terzan 5 field |
And then came Palomar 6 (by the way, this globular cluster includes the planetary nebula JaFu 1 in case you didn't remember). Despite its apparent faintness (if you can call it that) it was easier to see than Terzan 5 and appeared as a faint, round smudge in a rich star field with dark nebulae. After a success with Palomar 6 I went on to sketch Palomar 11 - again. Then I got back to even more familiar territory with open cluster NGC 6604 which I saw more of a large cluster with two concentrations than the tiny 5' cluster listed as NGC 6604. I really took a liking with this field which includes the emission nebula Sh2-54 in the background. NGC 6818 showed a definitive ring structure and Messier 75 two "bars" extending from the bright core.
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.
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.
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 |
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.
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.
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.
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.
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.
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.
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... |
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 |
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... |
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 |
Tuesday, 6 September 2011
26.8.2011 - Stargazing in Death Valley
Date: 26./27.8.2011
Observing location: Mosaic Canyon, Death Valley, California, USA (285 meters / 935 feet)
NE Lim.mag: 7.7m (zenith)
SQM-L: 21.72 (zenith)
Background sky: 9 (excellent)
Seeing: 8 (excellent)
Transparency: 8 (excellent)
Weather: +39.1 - 32.2°C, humidity <10%, a breath of wind from the north, thunderstorm in the SE.
Being a hardened veteran of Anza-Borrego as well as Palm Springs I knew
what was ahead when the sun set behind the mountains. Earlier in the
evening, the temperature had reached +48°C (118°F) down in Badwater. For our hotel that promotes astronomy by "renting binoculars for stargazing" they sure had a funny way of showing the love. About a mile to every direction of Stovepipe Wells, the glaring lights of the "town" will blind any starting star watcher (or more experienced) for sure. There was little more to do than escape this mini Las Vegas for a darker place near by; Mosaic Canyon.
It would be a shame to say when observing from a site with no visible light pollution I would start by sketching open clusters and I was well aware of this fact. So, I started with NGC 6559, M20 and NGC 6526 from the Uranometria's (Volume 2) A17-page. All of these nebulae displayed complex structure and required a lot of time to figure out. I especially liked NGC 6559 (smaller one on the left) which displayed 4 separate parts of nebulae at the eyepiece. Other two, not visible in this higher magnification sketch were IC 1274 and IC 1275. Both of these were quite difficult to discern but the dark nebula next to it - B91 - was actually quite obvious as a dark round patch in the middle of rich starfield and nebulae.
NGC 6526 turned out to be a little bit troublesome. Uranometria clearly shows this as an irregular shaped nebulosity between M8 and M20 but NGC/IC project disagrees; they list the object simply as the "SE part of M8" along with NGCs 6533, 6530 and 6523. This seems typical of William Herschel; cataloguing separate parts of one nebula with their own numbers. But there is a nebula in Uranometria's position for "NGC 6526" - if it is not it what should it be called? Well, I'm going to call it just that. Visually, I notice some variations in background brightness in this area when using UHC filter. Had I known that this a very faint object and in the middle of a star cloud, I surely would have spent more time with it. So it remains uncertain if I actually logged any nebulosity or simply the patchiness of the background sky caused by hundreds of faint stars. The sketch was doomed from the start as I knew the scanner would not be able to pick up my faint renderings without much background noise. For practical reasons, the sketch is only marginally cleaned up.
After three extensive (and exhaustive) nebula "studies", I had nothing else to sketch than open clusters so the couple worth mentioning would be NGC 6568 and NGC 6645. Then, continued by M17, M16 and a set of dark nebulae so I had my hands full for several hours. Later on some scattered clouds arrived but luckily it didn't interfere with my observing. This was a beautiful place to observe and a higher altitude would have probably made it a whole lot better. I especially enjoyed the naked eye views of the summer Milky Way so I continued to stargaze without equipment logging Messiers and several NGC objects with the naked eye. I had already noticed that during the past 4 years my eyesight has deteriorated to a point where I probably loose 0.3 - 0.5 magnitude with current set of eyeglasses. No matter, I still could enjoy the beautiful views.
Observing location: Mosaic Canyon, Death Valley, California, USA (285 meters / 935 feet)
NE Lim.mag: 7.7m (zenith)
SQM-L: 21.72 (zenith)
Background sky: 9 (excellent)
Seeing: 8 (excellent)
Transparency: 8 (excellent)
Weather: +39.1 - 32.2°C, humidity <10%, a breath of wind from the north, thunderstorm in the SE.
 |
| Sagittarius above Death Valley, CA |
 |
| Two brightest parts of NGC 6559 complex |
NGC 6526 turned out to be a little bit troublesome. Uranometria clearly shows this as an irregular shaped nebulosity between M8 and M20 but NGC/IC project disagrees; they list the object simply as the "SE part of M8" along with NGCs 6533, 6530 and 6523. This seems typical of William Herschel; cataloguing separate parts of one nebula with their own numbers. But there is a nebula in Uranometria's position for "NGC 6526" - if it is not it what should it be called? Well, I'm going to call it just that. Visually, I notice some variations in background brightness in this area when using UHC filter. Had I known that this a very faint object and in the middle of a star cloud, I surely would have spent more time with it. So it remains uncertain if I actually logged any nebulosity or simply the patchiness of the background sky caused by hundreds of faint stars. The sketch was doomed from the start as I knew the scanner would not be able to pick up my faint renderings without much background noise. For practical reasons, the sketch is only marginally cleaned up.
After three extensive (and exhaustive) nebula "studies", I had nothing else to sketch than open clusters so the couple worth mentioning would be NGC 6568 and NGC 6645. Then, continued by M17, M16 and a set of dark nebulae so I had my hands full for several hours. Later on some scattered clouds arrived but luckily it didn't interfere with my observing. This was a beautiful place to observe and a higher altitude would have probably made it a whole lot better. I especially enjoyed the naked eye views of the summer Milky Way so I continued to stargaze without equipment logging Messiers and several NGC objects with the naked eye. I had already noticed that during the past 4 years my eyesight has deteriorated to a point where I probably loose 0.3 - 0.5 magnitude with current set of eyeglasses. No matter, I still could enjoy the beautiful views.
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