| Reports | TAC | Join mailing list |
by Jay Reynolds Freeman
A group of San Francisco Bay area amateur astronomers took a long weekend over the August, 1999 new Moon, and spent four nights observing from the Bumpass Hell Parking Lot of Lassen National Park, a bit over 8000 feet up (2500 m) in the southern Cascade Mountains, at about latitude 40 N. There were two Lassen expeditions this year, but I had to miss the one in July because of work. I was anxious not to miss the August expedition, so I watched nervously as an unseasonal low brought clouds to the area during the few days before the event. On Wednesday, August 11, the forecast was still uncertain, but I loaded Harvey the Celestron 14 into my Geo Metro, and left Palo Alto at about 1:00 PM.
The journey took some five hours -- an hour to the far end of the Bay Area, not quite three hours cruising north in California's Great Valley, then an hour dodging Redding and climbing state 44 to the cabin-style resort just north of the park, where I had rented space. Clouds capped the mountains as I approached, but dissipated as I unloaded. When I arrived at the site, at dusk, the sky was clear. Heavy dew and a cold breeze promised chills, but I had plenty of warm clothes and had brought my Kendrick heaters and a humungeous battery, so I set up eagerly, and had Harvey operational by twilight's end.
My report last December of seeing the gravitationally lensed quasar, Einstein's Cross, in Harvey, had engendered some controversy, so with its location in Pegasus once more well placed, I thought it would be fun to try again. Darker sky than at Fremont Peak made the lensing galaxy, CGCG 378-15, easier to see -- I could hold it elongated with direct vision at 98x, in my 40 mm Vernonscope Erfle, and could see pronounced central brightening. More magnification gave a view which to my eye resembled the one I had last December, and a lot less jiggles from the calmer wind made it much easier to keep track of what I was looking at as I changed eyepieces and moved the telescope around, looking for stars to focus on. I tried 244x, 326x, and 489x, using respectively 16 mm, 12 mm, and 8 mm Brandons. The higher magnifications blurred out the far reaches of the galaxy to the point of invisibility, but magnified the central area and began to reveal its detail.
The best view for me was at 489x, and was intermittent, for seeing did not permit continuous critical observation at that magnification. Seeing also made it difficult to focus on so diffuse an object, but fortunately, there were several stars within a field or so of the target, that made the task much easier. With sharp focus achieved, what I saw when seeing settled was a blur that was not quite smoothly round, rather, that had structure, and the exact nature of the structure was difficult to identify. Using averted vision, some times I saw elongation in one direction, some times in a direction at 90 degrees to the first, and once or twice I glimpsed a multi-lobed pattern, perhaps cross-shaped but I would not wish to claim so definitively, but if so, it was reminiscent of the sloppily calligraphed 'X' of alphabet soup, novelty breakfast cereal, or certain brands of dry cat food. Alas, "Einstein's Kitty Crumblies" just doesn't have the right je-ne-sais-quois for an object half way to the edge of forever. I certainly did not see any of the lobes of the cross as separate: as last December, what I was seeing could be described in double-star terms as elongations, not separations. Occasionally the very center of the structure appeared as star-like as the stars elsewhere that I was focusing on. It would have been most interesting to view the Cross from a site this dark with excellent seeing, but no such luck.
I showed this apparition to about eight people, some of whom are regulars on the places where this internet posting will appear. I encourage them to present their own notes of these observations. We all had eyes with different degrees of near- or far-sightedness, and an 8 mm Brandon does not have enough eye relief to permit wearing glasses, so the drill was generally as follows: I would move the telescope to a nearby stars, call attention to the unsteady seeing, and let the observer focus to his or her own satisfaction. Then I would step to the eyepiece again, and without changing the focus, move the telescope back to CGCG 378-15, and return it to the observer. Fortunately, though several people chose a focal point noticeably different from the one I would have picked for my own eyes, no one's vision differed so much from my own that I could no longer see the objects.
Results differed. One person, admittedly a newcomer to deep-sky work, could not see anything at all in the field for the cross. One other saw only a diffuse object with no structure. Everyone else saw one or more of the anisotropies that I mentioned above. Each of those others at least saw elongation in one direction or the other, one or perhaps two saw it in both directions, and one person mentioned a 'V' shape. The experiment wasn't entirely "blind" -- we were all talking about what it was that we were seeing -- but at least one observer asked not to have the object described to him as he stepped to the eyepiece, and nonetheless saw anisotropic structure. I suspect I saw the most structure, but not because I have the best vision, rather because it was my telescope and I spent the most time at the eyepiece. It did take a long time to let everyone have a look: Harvey spent some two hours directed either at Einstein's cross or at the nearby stars we were using as focus targets. Some of that time was spent focusing, but most of it merely involved staring and waiting for the seeing to settle. Somewhere in the back row I hear lunar and planetary observers giggling, but remember, folks, we hapless deep-sky weasels aren't used to running large telescopes at magnifications more commonly reserved for diffraction-limited work.
It sure helped having a driven telescope with a convenient eyepiece position. Experienced observers who know the field and are familiar with the telescope can swap views in a big Dobson at 500x, but can you imagine using such a set-up to show something difficult to a line of people who do not meet all of those criteria?
I was tired from the drive up, and did not wish to push my endurance on the first night, for fear of propagating the fatigue through the rest of the weekend, so after the Cross-smitten multitudes had left, all I did before tear-down was look at a couple of double stars to check seeing and verify that we had not been wildly mistaken about the angular size of what we had been looking at. Still at 489x, both pairs of epsilon Lyrae were cleanly resolved, and indeed, spanned vaguely the same angular size as had the object at the heart of CGCG 378-15. Seeing was such that each pair always stayed well and obviously separated. There was no tendency for these stars to blur out in preferred directions, either -- nothing to make me think the elongations we had been seeing were effects of seeing. Of course, epsilon Lyrae was in a different part of the sky and somewhat higher, but I had not noticed any similar seeing sneakinesses on the focusing stars, either. On the other hand, gamma Andromedae, though still relatively low, showed as only two stars -- there was no hint of resolution of gamma-two.
Crystals of ice lay thick on car tops as I drove away from the parking lot, but soon enough I reached my warm cabin room, dialed the gas space-heater to a setting representative of a balmy day in the Sahara, drew the opaque hand-made curtains across the windows, and lay down on the bed to write up the evening's observations. Presently my lids grew heavy, so I yawned and stretched, pulled the blankets over my feet, turned off the light, and slept in comfort, peace, and quiet till well past noon. Waking slowly and drowsily, I made coffee -- a fine instant expresso -- from the piping-hot water in my thermos, heated a savory soup on my hotplate, munched sweet dried fruit and flavorful nuts, and spent the afternoon lolling abed, alternately dozing and reading a good book. As the sun sank low in the west, I arose again, thoroughly rested and sybaritically sated, took a long, hot shower, dressed, and set forth anew. Driving slowly through the mountains, past shadowed glens and rock-gorged ravines where meter-thick snowdrifts spurned the sun's heat, feeling the bite of the afternoon chill on the inside of my car's windows, I determined to exercise my humane instincts by gloating mercilessly at those of our number whose numbed, thermally-deprived thinking had confused amateur astronomy with denial of creature comforts, and so had camped out. It will be for their own good, I chortled, as I parsed and enunciated test samples of hedonistic braggadocio. Why, they might have caught pneumonia, or have been nibbled upon by bears, or -- the horror -- not have gotten enough rest to enjoy our next three nights observing. I have a good friend whose idea of roughing it is the Awahnee. Oh, boy, is she ever right.
Thursday night was not quite so dewy, but equally cold. I spent most of my time looking for new objects, often difficult and faint, but most of the things I looked at were familiar friends, such as Messier objects, that I wanted to see in the dark, transparent sky of our mountainside site, or solar-system targets that I look at routinely. I won't attempt to mention all of those in this report. My primary new targets for the evening were gatherings of galaxies -- Hickson groups and Abell clusters. I had been surveying the bright ends of these catalogs fairly regularly for not quite a year; it was time to take a peek at a few more. Working at 244x, I spotted three galaxies at the location of Hickson 72. Abell 2147 showed up as a 6-arc-minute milky field, with galaxy UGC 10143 and several other distinct galaxies which were not identified on any of my charts. Abell 2152 had approximately 10 distinct galaxies in a 10-arc-minute field. I had visited Abell 2151, the Hercules galaxy cluster, before, but not with a chart that identified any of its member galaxies, many of which have NGC numbers. I was able to chase down all the ones that are plotted on Millennium Star Atlas. Abell 2162 yielded NGC 6085, 6086, and several more galaxies. Abell 2197 had many NGC galaxies, like the Hercules cluster. And near Abell 2199 I found NGC 6158, 6166, and several more.
I looked at a few showpiece objects at 244x. M51 showed spiral arms with the delicate bridge to its companion, NGC 5195. I generally think of the bridge as requiring lower magnification, for it has low surface brightness, but did I say it was dark? M101 also showed spiral arms.
I had one project that involved re-examining things I had seen before. I did not find Barbara Wilson's records and finding charts (CCD images by Mike Morton and Tracy Knauss) for Terzan globular clusters until after I had started chasing down the very difficult members of this list. Most of the Terzan clusters are plotted in Millennium, and are in parts of the sky where there are plenty of stars to the atlas limit, so I had not had any doubt about the positions. but additional stars in the finder charts would be useful for verifying identification. I started at the beginning and worked part way through the list, in order. Terzan 3 was too low, but I found all the others that I looked for, namely Terzan 1, 2, 4, 5, 6, and 9, working my way east across the southern sky. My notes showed Terzan 1 as one arc-minute or less across, Terzan 4 as half an arc-minute, Terzan 6 as "faint", and Terzan 9 as "fainter".
There were some other things I wanted to look at, so I abandoned the Terzan list and switched magnification to 98x. I chased down the recently discovered Cetus Dwarf Galaxy. It is another one of those low-surface brightness dwarfs which have no "edges" or other sharp changes in intensity to draw the eye. With averted vision, I saw it as a 4 arc-minute diffuse patch that faded smoothly into the background sky. It was not really difficult to see -- other local dwarf galaxies are tougher -- but I must once again remind you that Lassen was quite dark -- we kept joking that if the Milky Way went away the sky might get truly black, and when Jupiter rose, it cast visible shadows.
A few "showpiece" objects were remarkable in such skies. M8, the Lagoon Nebula, appeared much vaster than I usually see it; pale peripheral nebulosity more than spanned the 40 or so arc-minute field of the big Erfle. I have seen such views at lower altitudes, but only with a narrow-band nebular filter. I had an Orion UltraBlock in my kit, but there seemed to be no purpose in digging it out. M17 was similarly enlarged, much bigger than the usual Swan. M16 was filled with structured nebulosity: I could see the Star Queen dark nebula (there is some uncertainty as to whether this name applies to the dark pillars so dramatically photographed by the Hubble Space Telescope a while ago, or to a concentration of cluster stars nearby), and another long dark streak that some call the Black Pillar, a ways away.
The Trifid Nebula showed unmistakable color -- the larger, trisected lobe was red, and the other pale blue. With smaller telescopes, or at lesser sites, the best I usually do is detect that the colors of the two lobes are different, but on this occasion, as on a few others that preceded it, there was no doubt as to what hues were actually present.
I found NGC 7331 and identified all five components of nearby Stefan's Quintet; namely, NGC 7317, 7318A, 7318B, 7319, and 7320. The Quintet is also a Hickson group, Hickson 92. M74 showed spiral arms. Lots of other things were as beautiful as you might expect them to be.
I had my head down for most of the evening, so saw only a few bright Perseids, but did look up for a very bright Iridium flare in the northeast, lots brighter than Venus ever gets. (I must say, that for all I favor exploration of space, I can't tell you what simple joy it gives me to see Iridium file for bankruptcy. May their affairs be tied up in court till the satellites rot and the Air Force uses them for target practice. May their investors lose every cent they ever touch. May their corporate officials all up in jail. May their stockholders and employees find thorns in their beds, weevils in their coffee, and half a worm in every apple they nibble. Nyah!)
I went back to my warm cabin, which was even cozier than the night before, because I had pre-set the heater thermostat to a nice pleasant bake. On the way back to the parking lot next day I noted cloud caps hanging over the ridges and mountains. They thinned as I was setting up, but as twilight grew into darkness, tenuous cloud continued to form over our heads and disspate a little way to the east.
I had gotten pretty cold the preceding two evenings, and my warm, snug cabin room had spoiled me, so as Friday night settled in I opened not one but two pair of the throw-away catalytic hand-warmer packets that I buy for $1.09 at local hardware stores. I put one packet in each glove, and one at the instep in each of my down booties. That worked like gangbusters! The cold didn't bother me at all. Actually, it wasn't really cold -- temperatures on my recording thermometer never dipped below 4 C the whole weekend -- but breeze and cold-soak did tend to make things uncomfortable at times. The rest of my observing garb, worn over a long-sleeved shirt and jeans, was a ushanka with the ear flaps turned down and tied under my chin, and a sweat shirt, down vest, and light lined windbreaker over my torso. I didn't even have to put on my wool Count Dracula cape. Nevertheless, having my hands and feet artificially warmed made a great difference in comfort.
My observing program for the evening featured Scorpius and Sagittarius, and Bumpass Hell is on the south side of Lassen Peak, so I could peer out from under the clouds with no problem. I spent about two hours chasing planetary nebulae, mostly from Jay McNeil's master list, at 244x. I had long since chased down all the easy planetaries that I could find in this part of the sky, and the ones that were left were, well, not easy. I found about ten, and identified the field positively for three more, but did not see them. I was careful to note whether or not I could detect a central star in every planetary nebula that I did see, but in only a few was I even able to make out enough of the nebulous shell to determine whether or not it was round. Later in the evening, still at 244x, I found a globular I had not seen before, E456 SC-38, in Sagittarius, and took another look at Stefan's Quintet. The galaxies in it were a little easier to see at the higher magnification.
I also took a look at NGC 6540, a rather odd cluster that is one of the toughest objects on the Herschel-400 list. Many people, including me, were a little surprised when I found it with Refractor Red, my 55 mm Vixen fluorite, in the course of a Herschel-400 survey in 1998. One confusing problem was that I could not find a good visual magnitude for it, and the photographic ones -- some of which are fainter than 14 -- are all likely very misleadingly faint, because objects in this part of the sky are mostly highly reddened, hence appear much brighter visually than in the blue wavelengths used for "photographic" brightness measurements. In any case, at 244x in Harvey, NGC 6540 did not look nearly as intimidating as its reputation would suggest. What I saw was an easy and obvious unresolved bright patch, elongated east/west, with two resolved clumps of stars superimposed. I have little practice estimating magnitudes at the eyepiece, but it was certainly not 14. Of course, in this part of Sagittarius, just above the spout of the teapot, there are lots of unresolved bright patches and lots of chance clumps of stars, so without stuff like spectra and color indexes and H/R diagrams and the like, it is hard to be sure just what is the cluster.
On that night also, I got gamma-two Andromedae as close to resolved as ever during the expedition. At 489x, I logged it as "resolution suspected", which meant that in the jumble of overlapping images of gamma-two, which obtained in the seeing conditions of the moment, I frequently thought I saw a fine line separating the two components, but was not absolutely sure. It had "the look of a double", as the saying goes. Harvey has in fact easily separated gamma-two, on nights of better seeing. The vastly wider separation of gamma-one from gamma-two was of course entirely obvious.
Friday night was the only evening of the four when I looked through someone else's equipment. Someone had one of those new Vixen 125 mm binoculars that Orion is selling, the latest model with the zoom eyepieces, and I got to try it briefly. At 38x, the Pleiades were well resolved, of course, and the Merope nebula was easy. I am a great fan of the Vixen 8-24 mm zoom eyepiece and also of binoculars, but it felt odd using this giant pair, simply because the binoculars that I am used to all have much wider apparent fields of view than does the Vixen zoom eyepiece. Vixen has a wonderful instrument with this big binocular, and it is a shame to see it hampered by less than excellent eyepieces. The zoom unit is a natural for this combination, and no doubt more versatile than any single-magnification built-in eyepiece, but I think Vixen should tweak the objectives to match them to the prisms, so that the combination is decently corrected for spherical and chromatic aberration at the focal plane (perhaps they have done so already -- it's either that or the eyepieces are a special model), then sell them with 2.00-inch eyepiece holders and let users put in what they will.
After another toasty overnight snooze, I returned to the parking lot for Saturday, our last night of observing. A lot local folks turned out, so I spent a while giving them views of the bright and the spectacular. Noteworthy among these objects was the Saturn Nebula, NGC 7009, pale blue with the delicate ansae clearly visible. I could not see the central star, though I have glimpsed it in Harvey before.
Still at 244x, I chased down some more difficult planetaries from Jay McNeil's list, occasionally using my UltraBlock monocle-fashion to confirm the objects by "blinking" them. At one point, I looked at the sky with my filter-covered eye, using the two-inch mount as a true monocle. It was fun to see the dark sky continue all the way to where it was cut off by the horizon, and to see how the already naked-eye North American Nebula became a bit more obvious. Next I found ESO 461-7 and three more galaxies of Hickson 86, picked up a couple more ESO galaxies nearby.
Then I looked for Terzan 10, and found it very nearly impossible. My impressions echoed Barbara Wilson's -- every now and then, I detected the faintest trace of a glow at the given position, north and west of an 11.8 magnitude star. The excellent CCD images that accompanied Wilson's write-up made the position not in doubt -- I could see lots of the stars near Terzan 10 that imaged fainter than the globular itself. I never would have suspected the object was there if I had not known exactly where to look.
The observation was sufficiently repeatable that I logged it, with the annotation "extremely difficult and intermittent", but it was certainly the toughest globular that I have ever seen. I don't think I was deceiving myself that I saw it, and it would be dishonest not to report that I thought I had done so, but make no mistake, this one was on the absolute ragged edge of my capability, with my Celestron 14 and with the conditions that obtained. Wilson has seen the globular in a 36-inch from the southeastern Texas, about half way between Houston and San Antonio, and suspected it in her 20-inch (she doesn't say from where). I am sure that my doing well with lesser aperture says more about the sky quality at Lassen Peak than about our relative skills at observing.
Now that I think of it, the recorded magnitude of Terzan 10 -- 14.9 -- is not out of line for a 14-inch, particularly since the object is small enough to be comparable in angular size to a galaxy of similar brightness. I wonder if processing in the brain is taking account of the nearby brightish star and making the globular less obvious. It would be interesting to repeat the observation with an occulting bar, to get rid of the star.
I switched to 98x and tried some easier stuff. I had never looked at Cygnus X-1 before, and found it an unremarkable star, bright enough for my finder, of course with nothing to indicate that it very probably involves a black hole. I resolved the finder-object cluster Roslund 5, then went hunting some of the more obvious Sharpless emission nebulae Using the UltraBlock, I found Sh 2-101 and 2-104, but then I put the filter aside, as the high sky was dark enough that it didn't make much difference. I found Sh 2-112 and 2-115 -- the latter was half a degree or more wide, then went on to review the Cocoon Nebula complex, which includes nebulous cluster IC 5146 (perhaps the nebulosity is also known as Sh 2-125 -- my sources are not clear). I believe it is the slightly hollow aspect of the enveloping bright nebulosity that gives this apparition its name, but the long, twisty, branched dark nebula, Barnard 168, that trails westward from the cluster proper, also resembles dark matter swaddled in the brighter material. I could trace this cloud to a position somewhat west of the right ascension of pi-two Cygni.
Moving north to Cepheus, I found broad Sharpless 2-132 and the little cluster Berkeley 94 that it overlaps. Then I went on to study the complex dark nebula that involves Barnard 169, 170, and 171.
Gloating about warm rooms notwithstanding, I could not help but notice that even though Saturday night was superb, nearly all of our company left by midnight, claiming fatigue and perhaps the need to pack up a campsite the next day. I have no complaint about people who like to camp out, but I suspect that some of those folks were there to do astronomy, and it seems a shame not to select habitation and creature comforts that adequately support that hobby. I was well-rested, which no doubt contributed to my not noticing the cold, and besides my telescope, had only a small suitcase to pack.
At least the absence of people encouraged the local wildlife to come out. I had seen playful Clark's Nutcrackers flying around the site at night, and had heard scurryings and scamperings occasionally in the brush, but saw no local nocturnal denizens until the dry rustle of crumpled plastic wrap alerted me to a guest in my car. The right door was open, but the left one was closed, so the small critter sitting on the driver's seat, mouthing some goodie flitched from my litter bag, was not entirely sure what to do when I peered in from across the car. The furry bandit was not a species that I knew well, and my red LED flashlight made its true colors hard to determine, so it was not till after subsequent consultation with my mammalogy books that I identified the animal as a long-tailed weasel. Weasels allegedly possess more predatory prowess per pound than almost any other North American wildlife, but this little creature seemed polite and diffident, almost friendly, as it climbed carefully over the seat, crossed equipment and carriers in the cargo area, and egressed through the hatchback. It was probably used to a human presence, and no doubt wondered why we hadn't gone away so that it could make its nightly rounds of the parking lot in peace and quiet. I just smiled. I don't really mind animals in the car -- raccoons are frequent visitors -- and I certainly cannot object to a visit from a real deep-sky weasel. Besides, it could have been a bear.
I looked at a bunch of showpiece objects, then called it a night. After yet another warm, restful sleep, I had an uneventful drive back down the valley, and home. Lassen Peak is a wonderful place to do astronomy; I can hardly wait till our next expedition to Bumpass Hell.