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by Randy Muller
On Bastille Day, Wednesday, July 14, 1999, Gary Manning and I packed our 10" f/6 and f/5.6 dobsonian scopes into his truck, throwing in some camping gear and too much food (but not enough good food), warm clothes (but not warm enough clothes) and took off for Mt. Lassen Volcanic National Park, site of the 6th Annual Lassen Star Party.
This was Gary and my first time participating in this outing, and we were looking forward to clear, dark skies not available within 100 miles of the Sacramento light pollution.
We took the slow scenic route and drove up highway 32 from Chico. This was the same route that I took on a bike trip from Mill Valley (13 miles north of San Francisco) to Lassen in 1973, and I was surprised at how little it has changed. The ride in the truck was considerably easier, though. I remembered some of the places I rested, being sick from eating too much Philadelphia Cream Cheese. Even the names of the businesses at Forest Ranch and at the junction of 89 and 32 had not changed.
The scenery in the park had also not changed in 26 years -- the breathtaking vistas, the magnificent mountain and associated peaks. There was also lots of snow -- that was different from 1973, a drought year for Northern California. In fact, we were surprised to see various lakes half covered with ice and lots and lots of snow and even some snow in the campground.
When we arrived at the campsite, we were lucky to pick the right loop the first time, and quickly located Mark, Dean, Richard Navarrete and Rich Neuschaefer, the Ancient Tacos. We established ourselves in a camp nearby and ate our primitive dinner. The weather was pleasantly warm. During dinner, I planned my observing session for the evening by deciding to explore the galaxy-rich area in NE Virgo, which is chart C46 in the Herald-Bobroff Astroatlas.
My "official" observing program is chasing down the Astronomical League's Herschel 400, but, not wanting to repeat the same mistake when I did my first Messier survey, I also stop and look at objects not in the formal program I am pursuing. I see a lot more this way. For two years, I observed virtually nothing but Messier objects, and my logs show it.
Tonight, I dispensed with the Herschel 400 list altogether, and just picked a likely looking chart in which to hunt galaxies. I ended up observing 17 new galaxies, but that included only one new Herschel.
We were joined a short time later by Brad, a physics student at Chico State. I had majored in physics, but switched to applied math, so Brad and I enjoyed talking about nuclear physics, and how much we hated partial differential equations and Laplace transforms. It brought me back to the days of my youth. Brad had an original Coulter 10" f/4.5 dob. It was a short, stubby little feller.
We arrived at the Bumpass Hell parking lot about an hour before sunset, and the observing conditions looked ideal: The southern horizon appeared to be BELOW level. To the east and west were low ridges, and to the north was Mt Lassen itself, but who cares about the north?
There was plenty of room to set up, and a solitary tree -- right in the south, but it was not very high, having been somewhat stunted by the 8200' altitude.
There was horrid, stagnant air pollution-laden air, mostly below us, but at our level, too. It did not seem like ideal observing conditions.
I was eager to try out my new Novak mirror cell -- I had already field tested it at Blue Canyon, but it didn't get very cold last Saturday night, so I thought this would be a good test, at a significantly higher elevation. The new mirror cell is open in the back, allowing the mirror to cool quickly to ambient temperature. The original cell had three small holes and lots of bulk, which prevented the mirror from ever cooling off, resulting in bad images and ghosts.
I was also particularly interested in examining Marsha Robinson's refurbished 10" dob. This scope started out its life very similar to mine, and I wanted to inspect Mark Wagner's handiwork. The crummy old mirror cell was replaced by a Novak cell, as I did on mine, but he also completely rebuilt the base and totally replaced the bearings. It was very smooth, and the new base raised it up to a somewhat better height.
Marsha's scope now looks like a piece of attractive artwork, whereas mine is looking more and more like Frankenstein's monster with each change I make.
After the sun set, Venus was very bright and prominent in the sky, so I took a look at it. It showed a nice medium fat crescent, about the same as Saturday night (July 10). It had nice shading at the terminator. The image was dancing around a bit in the poor seeing.
I could also tell that the mirror was very close to equilibrium, and the images were much improved over my old mirror cell.
Mars was also up, so I swung the scope over and saw a pronounced gibbous shape to the disk. After studying the image and waiting, it eventually showed the tiny North Polar Cap and Hellas cocked to one side. It seemed like there might have been some dark patches, but the seeing didn't permit viewing such detail.
Waiting for darkness, I took a look at M4, a bright, big loose globular cluster in Scorpius. This is one of the nearest globular clusters. I also checked out M5, another denser, brighter, smaller globular; one of the most beautiful globular clusters in the sky. I've heard some say that globulars all look alike, but these globs could not be more different. I've also heard others say that all trees look alike.
While it was still twilight, but darker than my home, I ran down Markarian's Amazing Chain of Cool Galaxies in Virgo, starting from M84/M86 to M88. This is my favorite area of the sky, and it was locked in western twilight, but I wanted one last look for the year.
It was still getting darker when I decided to go after some galaxies I had missed on Saturday night near M5. I quickly sketched a small group of 4 galaxies in a row: NGC 5850, 5846, 5845, and 5839. These are each about 10 arcminutes apart and are regularly spaced almost on a line. Two of them are very bright, and two are fairly dim, though still easy to see. I sketched them so that I could ID them later with my sky charting software -- the NGC numbers were all somewhat jumbled in my printed sky atlas.
When it finally got dark, the sky was inky black, and the stars and Milky Way shown vividly. The darkness was astounding. This was much darker than Blue Canyon, which I often observe from. This darkness rivalled the sky at Fiddletown in January, when Sacramento was covered with a light-damping blanket of thick fog.
There were at least two light domes in the south: A small faint one due south, and a smaller one in the southwest. The one due south was obviously distant, and therefore huge. It was also fairly complex, consisting of at least two layers: A brighter lower layer, and a fainter, but higher layer. Looking at a map, I noticed that Oroville, Marysville-Yuba City and Sacramento are all due south of Lassen. I guess that the lower layer is a combination of Oroville and Marysville-Yuba City, and the higher, fainter layer was due to my personal light-pollution nemesis, Sacramento.
The one in the southwest seemed to be fairly close, and might have been Mineral, but was possibly Chico.
Next, I accidentally reobserved NGC 5746, a bright (mag 10.3) Herschel 400 galaxy that I had observed from my backyard a little over a year ago. But it's a beautiful sight -- an edge-on, very elongated galaxy with a brighter bulge in the center. Nearby lay 5740, a dimmer and more diffuse galaxy.
About 2 degrees south lay 5750, a diffuse round galaxy. About 2 degrees west lay a group of dim galaxies, 5713, 5719, 5691 and 5705, at magnitude 12.7, the faintest and most difficult of the group. It was diffuse, shapeless and very difficult.
I next re-observed, by accident, a nice pair of galaxies 5775 and 5774, about 5 degrees to the NE. I described 5774 here as "the dimmer of the pair", while at Blue Canyon the previous Saturday night, I stated it was "at the limit of detection -- extremely faint smudge". So this sky was significantly darker than Blue Canyon's 4 days earlier.
I took a break and spent some time showing people various naked-eye Messier objects. In particular, M8, the Lagoon Nebula, looked absolutely fabulous against the inky blackness of this incredible sky. I've never seen it so huge and swollen. It reminded me of the first time I saw the Great Nebula in Orion from a dark site earlier this year: It was much larger and possessed more and longer extensions and tendrils of glowing gas than I ever imagined I would see visually. At this dark site, M8 looked enormous, bright and detailed, and it just kept going and going and...
Partly to be a little perverse, and partly because the Milky Way was reaching the zenith, I elected to continue my galaxy hunt closer to the Milky Way, where there is a dearth of galaxies due to obscuring dust. Somewhat east of where I started. making an elongated isosceles triangle with the pair of stars Yed Prior (delta) and Yed Posterior (epsilon) in Ophiuchus (the Serpent Bearer), I resumed with NGC 6118, which I saw as a faint, diffuse oval. This was my one and only Herschel 400 object during the entire trip. I looked for nearby 6172, but failed to see it.
Quite a ways north, I hit the group NGC 5970, 5957 and 5956 in Serpens. I was also checking my mirror periodically for tube currents as the temperature went down fast. The mirror stayed right with the air, and there were never any tube currents. The images of the stars were always clean and crisp.
I began to get cold. I was wearing light thermal underwear, a sweater, a heavy jacket, flannel pants and a hat. I would have been fine, except the wind was blowing from time to time. My neck was protected only by the wind-break hood of my jacket, and I could never get the tie strings tight enough to stop the wind coming into my hood. When my neck felt cold, my whole body felt cold.
I also began to get sleepy, but I wanted to make the most of the night, since it was so dark. So I began sitting for periods of time, with my head cocked back, just looking at the beauty and detail of the Milky Way, which was now shining brilliantly directly overhead.
The detail in the rifts and star clouds through Cygnus, Aquila, Ophiuchus, Scutum, Mighty Sagittarius and Scorpius were amazing and commanded my attention as I just sat there, slack-jawed, drinking my fill of light from the Milky Way.
My tiredness and coldness were getting worse, so I decided to walk around a little bit. That helped the coldness quite a bit. It was an eerie experience walking up and down the middle between the two rows of approximately 20 or so scopes. They were easy to see in the ghostly light of the stars and the Milky Way, and the big dobs were tilted this way and that.
Periodically, Brad came over and we would talk about math and school, and how much college math I use in my work (software engineering), to which the answer is: Virtually none.
Around this time (about 2am), almost everyone suddenly left. Mark Wagner, before he left, tried to scare me with tall tales of some Mexican unidentified species of monster that had happened to migrate right to this area. This attempted torment brought back warm memories of my friends brothers telling me nearly identical tales of Big Foot having been sighted on Mt. Tamalpais, near where I grew up.
Gary and someone else were slumbering away in their vehicles. A quietness descended upon the parking lot as Brad and I were the only ones left observing. This was the same quietness that was present at Fiddletown in January. Suddenly, the night took on a magical, dreamy quality, and although I was cold, tired, sleepy, and not very productive in my obesrving, I really enjoyed this time. When I got too tired, I would just look at the Milky Way and smile.
I forced myself to get back to the eyepiece, determined to remain until it started getting light in the east. I observed the Great Cluster in Hercules, M13, probably the finest globular cluster in the northern sky. Nearby was my real quarry: NGC 6207, a small, dim oval galaxy. A bit further away was the even dimmer object, NGC 6196 -- another galaxy. At published magnitude 12.9, this was the faintest object I observed this evening, and my notes read, "very faint, round, very concentrated in center, small".
Next, I observed 6181, almost 2 degrees away from Beta Herculis, which I see as Hercules' left knee (assuming Hercules is facing us). I was now having difficulty concentrating.
Near what I see as Hercules right foot, and near Ophiuchus' head, I observed a cute little trio of galaxies, the final deep sky objects for the evening: NGC 6500, 6501 and 6495. 6500 and 6501 were only separated by 2 arcminutes, and it required my 10mm (142x) to show them as separate and distinct galaxies. I just love groups of galaxies, in any number.
At this point, Brad came over for the last time, talking excitedly about Saturn. I swung the scope over and was struck by the wealth of fine detail. The seeing had improved quite a bit. I immediately identified the moon Titan, and three others in a triangle closer to Saturn. These were Tethys, Dione and Enceladus. I did not see any others that I recognized as moons, but there were some other possible candidates.
Cassini's Division in the rings was obvious and well-defined, and the South Equatorial Belt was fat and dark. The rings were more tilted than last year, and the north limb of the planet just barely showed below the ring.
I swung the scope over to Jupiter, and was met with the blindingly bright, huge image of Jupiter. The four Galilean moons were present and accounted for, and there was a small contrasty dark spot in the North Equatorial Belt. The seeing was coming and going, and when it was good, I caught glimpses of vast detail in the cloud belts, including complex knots and curliques. If I hadn't been so tired, I would have logged more of this stuff.
I continued observing until the sky began to brighten in the north east. Brad had finally retired to his camper. My body and my brain were shot and I achieved my goal, so I woke up Gary, and we went back to our campsite and slept.
It was a great night, and the darkness was just incredible.
| Date | July 14/15, 1999 9pm-4:30am (0400-1130 July 15 UTC) |
|---|---|
| Location | Bumpass Hell, Lassen, California, USA (40.457N, 121.5W) |
| Altitude | 8200 ft. |
| Instrument | Orion DSE 10" f/5.6 dob-newt |
| Oculars | 7.5, 10, 17, 26mm Sirius Plossls |
| Seeing | 8/10 Pretty good, but a bit fuzzy |
| Transparency | 9/10 Fantastically clear |