The majority of the winter rains seem to be behind us here in the Willamette Valley; this winter was quite an improvement over the last several as far as astronomy goes, and hopefully the spring and summer are as good as usual clear-night-wise. Although my work shifts were being canceled at an alarming rate, I couldn’t complain about a good forecast on the Clear Sky Chart for a Sunday in March. A good number of my fellow EAS members felt the same way, so plans were made to convene at Eureka Ridge—-due to its better southern horizon—-for a potentially long session with the stars.
Throughout the day, the constant stream of cirrus clouds overhead seemed intent on making a liar out of the CSC. I ducked off for a nap at 3 PM, expecting the cirrus to disappear before load-up time, and was relieved to find that this was mostly the case when I awoke. The transparency was still not ideal, but it would suffice. I could simply observe objects higher in the sky, where the transparency would be at its best—-about a 5 on the 10 scale, in my estimation, based entirely on the color of the daylight sky.
Someone rearranged the potholes on the BLM road to Eureka Ridge since we’d last been there, as the gravel road was a minefield. I’d expected some potholes and a lot of tree debris, but there was no debris of note on the road, and the potholes were more numerous than ever. I passed a large vehicle that was stopped off the roadside about halfway up, and it ended up following me the rest of the way as I picked my driving spots between the potholes at 5 MPH.
Only two types of people would be on the BLM road in the evening: sovcit types with full arsenals, and astronomers. I passed a pair of the former as I pulled onto Eureka Ridge proper; they stood beside their truck with impressive rifles out, aiming down into the bowl of which Eureka is the north ridge. Astronomers outnumbered them, however, as there were eight of us there by sunset. (Of the eight, I knew only Jerry, Kathy, and Frank, although I recognized most of the others from EAS meetings.) Every thirty seconds or so, a shot would ring out, and we would either hear a metallic clank (if they hit their target) or silence. I joked that the clank was just a sound effect added to impress us with the shooters’ accuracy, and that they were really just shooting into the air.
The skies at Eureka aren’t as dark as those at Eagle’s Ridge; there’s about a half-magnitude difference between the sites. Eureka has the advantage of a flat southern horizon (although the light dome of Roseburg, 60 miles south, is quite prominent) and better east and west horizons that at Eagle’s Ridge. The disadvantages to Eureka, aside from the not-as-dark skies, are that it’s often windier than the “Eagle’s sites” and that dew is often a major issue. On this night, the wind wasn’t a problem, which may have made the dew even worse. By the time Bob the Dob was collimated and ready for action, it was already damp with condensation.
I intended to pick up where I left off last time, digging out the remaining Herschels in Lepus and continuing north and east. The transparency was pretty poor so close to the horizon, but the lack of mountains made it much easier to “get low” declination-wise, and I ended up sitting on the ground a lot to observe. This had been a never-ending source of amusement when I was with AASI, the members of which thought it strange that with the whole sky to work in, I would insist on observing as low in the south as I could manage. Here in EAS, though, no one gave it a second thought. In any case, the seven degrees of latitude difference between Carbondale and the Eugene area meant that several of my Herschel targets were low enough to require observing from the ground—-even some of the Messier objects were horizon-huggers from 44˚ North.
The observations that follow are compromised by the low altitude and declination of the objects I ended up observing. I noticed as I was transcribing these that the star magnitudes and galaxy sizes I had indicated are considerably off; the poor transparency of the southern sky dimmed field stars and washed out faint galactic haloes to the point of invisibility. I was working on objects as near to the meridian as possible, which is good operating procedure in any case, but many of these objects simply weren’t going to be able to successfully fight the gunk in the sky’s lower third. Should I have stuck to objects at higher altitude/declination? Possibly. But many of these targets would be more difficult at Eagle’s Ridge and impossible at Eagle’s Rest (the gravel pit) due to obstruction along the horizon, so they’d need to be observed at Eureka anyway. So I plowed ahead, knowing as I did so that these notes would be less accurate than they would be in better conditions.
3/11/18
EUREKA RIDGE
MOON: 25 days (21% illumination); rose at 4:57 AM
SEEING: 7
TRANSPARENCY: 5; 4 below 30˚ altitude
SQM: 21.3
NELM: not checked
WEATHER CONDITIONS: temps falling to mid 40s; some breeze below ridge level, high humidity/ground fog
OTHERS PRESENT: JO, KO, FS, JL, JP, Bob M, MD
8:34
NGC 1964 (Lep): still not totally dark—galaxy dimmer than when I saw it in Illinois—elongated S slightly P-N slightly F—1.5′ x 0.67’—has a bright core and bright stellar nucleus—halo fairly diffuse—may be a threshold star just on P edge of halo—ends of halo very difficult, not defined—P very slightly N of galaxy by 2′ is a 10.5-mag star; N very slightly P that star by 2.5′ is a 10th-mag star; P slightly S of that star by 0.5′ is a 12th-mag star—SP the galaxy by 5′ is an 11th-mag star
At this point (or thereabouts), one of the observers made note of the zodiacal light in the northwest. Caused by sunlight scattering off of dust in the ecliptic plane of the solar system—-and therefore along the Zodiac—-the zodiacal light requires very dark skies to be seen. It’s a faint triangular glow that stretches from the horizon southeast along the constellations of the Zodiac. (It actually covers the whole sky, but is usually too dim, even from a dark site, to be seen aside from its brightest portion.) On this night, the zodiacal light reached beyond the Pleiades, a faint triangular mist that served as an extra reminder of how fortunate I was to have skies so free from the artificial glow of humanity.
8:53
NGC 2139 (Lep): already missed 1162—galaxy is kind-of impressive—face-on spiral based on brightness profile—quite diffuse—slightly brighter core—threshold stars around galaxy? Hard to tell if nucleus present—somewhat elongated mostly P-F—1.25′ x 0.87’—brighter central region is 2/3 of length of galaxy—bracketed on S by a 10th-mag star 4′ from galaxy and by a 12th-mag star N very slightly P galaxy by 5’—3.5′ N very slightly P galaxy (in a line between galaxy and 12th-mag star) is a 13.5-mag star—N of galaxy by 5.25′ is a 13th-mag star (three stars make a small triangle)—N of galaxy by 1.5′ is a 14.5-mag star—back to 11th-mag star S of galaxy: a 14th-mag star S of that star by 1.25’—S of galaxy by 15′ is a 9th-mag star; another 9th-mag star P slightly S previous star by 6′, two brightest stars in field
9:12
NGC 2196 (Lep): on Lep-CMa border, way low in sky—pretty round—diffuse halo, brighter core (redundant tonight)—substellar nucleus is pretty obvious—1.0′ round—another face-on?–in middle of diamond of 10.5-11th-mag stars; closest star is 10.5-mag, NF galaxy by 9′; clockwise in eyepiece: faintest star of four (11.5-mag) NP galaxy by 11′; NP that star by 3.5′ and 4.5′ are 12.5- and 13th-mag stars; back to galaxy: 11th-mag star P very slightly S by 9.5′; brightest in diamond is S very slightly F galaxy by 13’—14th-mag star S very slightly F galaxy by 2.5’—another 14th-mag star P very slightly N of galaxy by 2.25′; another group of stars extends N and arcs S from that previous star and ends at star on P corner of diamond—N slightly P galaxy by 21′ is an 8th-mag star—NF galaxy by 19′ is a 9th-mag star
9:53
NGC 2781 (Hya): not at all impressive—reasonably bright—small, well-defined—0.67′ x 0.25’—conditions pretty poor down here—small brighter core, stellar nucleus—elongated P-F? hard to tell—S very slightly P by 8′ is a 9th-mag star—SF by 3.5′ is the dimmer of a N-S pair separated by 0.5′; stars are 13th- and 13.5-mags—N of galaxy by 2.25′ is a 13.5-mag star—P and slightly S of galaxy by 16′ is a 9.2-mag star
10:07
NGCs 2889, 2884 (Hya): diffuse but pretty obvious glow—reasonably large—roundish—1.5’—somewhat brighter core, but no visible nucleus—halo pretty well defined—S by 1.5′ from center is a 12.5-mag star—SP by 3′ is an 11th-mag star—F very slightly N by 12′ is a 10th-mag star—P and somewhat N by 16′ is an 11th-mag star; NF that star by 8′ (NP 2889 by 13′) is another galaxy (2884): smaller than 2889—edge-on—1.0′ x 0.25’—elongated N-S—hint of brighter central region but not well-defined in core or halo—NF by 5′ is a pair separated by 0.3′; the more S (and very slightly F) of pair is brighter; 13.5- and 14th-mags
10:28
NGC 2765 (Hya): continuing streak of unimpressive Hydra galaxies—small, reasonably well-defined galaxy—0.67′ x 0.25’—small brighter core—in averted there may be a flicker of a nucleus—not particularly bright but fairly obvious—elongated mostly P-F—F and somewhat S by 8′ is a 11th-mag star—S very slightly F galaxy by 8′ is a 12th-mag star; just N of that star by 0.75′ is a 14.5-mag star—S very slightly P galaxy by 5.5′ is a 14th-mag star—N very slightly F galaxy by 5′ is a 13.5-mag star
11:01
NGC 3078 (Hya): down as low as chair can go—galaxy is barely elongated N-S—0.67′ x 0.5’—brightish core but no nucleus seen—pretty well-defined halo—in middle of N-S elongated cross pattern—SF by 11′ is the brightest star in pattern (11.5-mag) that also serves as F-most vertex of tiny triangle; P that star by 1.5′ is a 13.5-mag star; from 13.5-mag star SF by 1′ is a 14.5-mag star—NP galaxy by 4.25′ is a 14.5-mag star—another 13.5-mag star N very slightly F of galaxy by 3.5’—SP galaxy by 5.5′ is a 12th-mag star which has a 13.5-mag star 0.75′ N
NGC 3109 is not a Herschel object, but is noteworthy for another reason: it’s the “fourth spiral” in the Local Group, that small association of nearby galaxies that makes up our cosmic neighborhood. There have been decades of arguments over 3109’s membership in the Local Group, but more-recent data appear to support its inclusion. So it joins the Milky Way, M31, and M33 as a major member galaxy on our block.
My notes on it give evidence of the difficulties of observing on this particular night. I considerably overestimated the size of NGC 3109, due to its diffuseness; it was hard to tell where the galaxy ended and the hazy, grey background sky began. Transparency, eyepiece fogging, low declination, and the light pollution of the southern horizon combined to make this extremely-dim galaxy a very difficult catch, more so than it would be if it was ten degrees higher.
11:12
NGC 3109 (Hya): poor conditions for this galaxy—huge, extremely-diffuse glow—18′ x 3.5’—elongated P-F—couple of brighter patches along length—several embedded stars including a 12th-mag star on F end—just on edge of one of brighter patches on P end of galaxy is a 13th-mag star—along S edge of galaxy, running SP-NF is an arc of 12th- and 13th-mag stars that terminates on P end with an 11.5-mag star—fainter than 4236 in Draco—not much definition—need to revisit under much better conditions
11:24
NGC 2986, PGC 27873 (Hya)–2986: better than many of the previous—probably an elliptical—0.75′ round—much more obvious core [airplane through field!]—maybe a flicker of a stellar nucleus—2′ from P edge of galaxy is either a threshold star or another galaxy, probably a galaxy (PGC 27873)—looks a bit extended or diffuse—very tiny, hard to tell orientation—to F and SF of 2986 is a zig-zag of four stars, brightest of which is second from N end and dimmest at S end; stars all between 10.5- and 12.5-mags—P and slightly S of galaxy by 10′ is a 12th-mag star—NP galaxy by 10.5′ is a double star; brighter component NF the dimmer by 0.75′; very unequal; brighter component (9.5-mag) is brightest star in field; dimmer component is 13th-mag; P and somewhat N that double by 18′ is another double of very unequal (10th- and 13th-mags) components; 10″ separation; brighter SF the dimmer
11:43
NGC 2784 (Hya): on Hydra-Antlia border—better galaxy than most tonight—bright, fairly small—elongated P very slightly S-F very slightly N—well-defined—unmistakable substellar nucleus and bright core—1.25′ x 0.5’—very obvious in field—in long triangle of 10th/11th-mag stars; brightest (10.25-mag) is NP galaxy by 6.5′; closest vertex is F slightly S galaxy by 3.5′, 10.5-mag; third vertex due S of galaxy by 5.5′, 11th-mag—N of galaxy is a small Cepheus-shaped asterism comprised mostly of 12th/13th-mag stars—rich field of stars
12:06
NGCs 3511, 3513 (Crt): 3511: very large thin galaxy—quite diffuse—elongated P very slightly S-F very slightly N—4.0′ x 0.67’—mottled along length—a bit of central brightening but more generally mottled—on F end of halo is a 13th-mag star—no visible nucleus—threshold star on P end—like 2613?—almost halfway between the two galaxies and a little bit P that point is an 11.5-mag star flanked on NF and due P by 12.5-mag stars; star to due P is 2′ and star NF is 3.5′ from 11.5-mag star—P slightly N of galaxy by 11′ is a 10th-mag star—bright zig-zag of 10th- to 13th-mag stars N and NF galaxy by 13-15’—NF galaxy by 24′ is a 9th-mag star—S slightly F 3511 by 11′ is 3513: very large, equally diffuse, roundish glow—maybe a slight bit of NP-SF elongation—2′ x 1.75’—some slight central brightening that’s not much brighter than halo—central region about half galaxy’s diameter—just off F edge of halo is a 14th-mag star—from SP side of galaxy by 4.5′ from nucleus is a 12th-mag star—from S very slightly P side of galaxy by 4.5′ is another 12th-mag star—S slightly F galaxy by 3′ is a 13.5-mag star; 13.5-mag star 4′ S that star
12:20
NGC 3585 (Hya): another bright, smallish galaxy—well-defined—elongated P very slightly N-F very slightly S—1.25′ x 0.5’—forms a nearly-equilateral triangle with two 9th-mag stars to F and SF by 8.5’—[very slow satellite across middle of galaxy]—S by 8′ is a 12th-mag star—due N of galaxy by 12.5′ is an 11.5-mag star; due N of that star by 5′ is an 8th-mag star—P and slightly N of the galaxy by 9′ is a 12th-mag star; P and slightly S that star by 10.5′ is an 8th-mag star
Somewhere during the course of the night, I had to start using the hair dryer I’d borrowed (last year!) from Randy B–a portable 12-volt dryer made for camping, and perfect for defogging a dewy eyepiece. I ended up kicking myself while using it; I have a dew-prevention system with a heater band for eyepieces, and never thought to bring it. I managed to repeatedly remind myself to bring the dryer, but bringing the Kendrick heater never occurred to me. Ugh.
The number of astronomers on the Eureka road was dwindling quickly; Frank and Bob had left earlier, shortly followed by Mike and Jeff P, and now Jerry and Kathy were heading home (having had a busy week). So Jeff L and I were left to work on our own projects: Jeff was working through as many Messiers as he could get to, given the fog-slash-humidity causing so many issues. Given the poor conditions so low in the sky, I should’ve made my way up into Leo and Leo Minor as I had long been planning. But the southern horizon at Eureka made it tempting to stay farther down in declination, and I ended up doing several more observations sitting on the gravel of the ridge road.
12:40
NGC 3621 (Hya): huge, mottled, and impressive!—elongated N very slightly P-S very slightly F—inside a diamond of stars whose major axis is oriented NP-SF—galaxy very irregularly bright and mottled—a little brighter on N end in interior—fairly diffuse halo but better-defined large core—edges of halo poorly defined—7.5′ x 3.5’—Messier-sized!—seeing really poor now, and eyepiece fogging up again—interior region/core about 60% of diameter—NP end of diamond is a small triangle, star on SF end is second-brightest in diamond at 11.5-mag; star on S slightly P end of diamond just a shade brighter than star on SF end; star on NF end is 13.5-mag; star on NP end is 13th-mag and has two 15th-mag stars SF and F slightly S from it, 0.5′ from 13th-mag star—S of galaxy by 9′ from galaxy’s center is an 11.5-mag star—NF galaxy by 16′ is an 11th-mag star—another 11th-mag star NP galaxy by 15’—very rewarding galaxy!
12:58
NGCs 4105, 4106 (Hya): obviously interacting—nice pair!—4105: elongated slightly NP-SF—4105 larger and slightly brighter of pair—obvious core—substellar nucleus—0.75′ x 0.5′ –S by 2.75′ is a 13th-mag star—an 11.5-mag star P very slightly N by 7’—21′ SP is a 10.5-mag star—4106: elongated SP-NF—0.67′ x 0.5’—halo more diffuse—smaller, less-defined core—1.0′ between centers of two galaxies—4105 is P very slightly N of 4106—NF 4106 by 14′ is an 11th-mag star—just off S end of field (26′) is a 10th-mag star
My usual method of finding an object involves locating it on a paper chart (either Sky Atlas 2000.0, the Interstellarum Deep-Sky Atlas, or the Pocket Sky Atlas, but usually the first), determining my guide stars, and then using the TriAtlas app on my phone once I’d gotten close. Unlike most of my fellow astronomy nuts, I find planetarium apps like Sky Safari to be unwieldy for selecting guide stars, even with its adjustable scale. But using a paper atlas usually involves getting up and going over to my gear table, which most often is next to my van. This isn’t actually a problem, as it forces me to get up and move every few minutes, keeping circulation going.
Getting up this time, though, I noticed that the fog —-formerly creeping up the floor of Eureka’s bowl—-was now glowing white along the road a hundred feet ahead of my van, like the vampire cloud from the original Star Trek. It was more than a little bit eerie to watch the fog encroach, gleaming white amid the darkness of the night.
1:24
NGC 3145 (Hya): near Lambda Hya, which makes observing the galaxy difficult—elongated S very slightly P-N very slightly F—1.5′ x 0.5’—if Lambda wasn’t here this would be a fine galaxy—brightish core and substellar nucleus—Lambda Hya is NF galaxy by 8’—a 12th-mag star SP galaxy by 3.5’—NP galaxy by 4′ is a 14.5-mag star—with galaxy centered, just outside edge of field due S of galaxy is a 7th-mag star—N of galaxy by 21′ is another 7th-mag star
1:39
NGC 3732 (Crt): small and less-impressive than last few—0.5′ round—small brighter core—no visible nucleus—pretty well-defined halo—SP galaxy by 1′ is a 13.5-mag star—galaxy has line of stars P and N of it; lines meet at a 14th-mag star 6′ S very slightly F galaxy—a 13.5-mag star N of galaxy by 3’—also N of galaxy by 8.5′ is a faint pair oriented N-S with brighter to N, mags 13 and 14.5, separated by 12″—NP the galaxy by 6′ is a 12th-mag star
1:57
NGC 3892 (Crt): fairly small—pretty well-defined—has a slightly-brighter core but no real visible nucleus—elongated P-F—0.75′ x 0.3’—P galaxy by 15′ is a 10th-mag star; a southward-curving arc of five 13th-mag stars loops S from the 10th-mag star back N to the galaxy—NP galaxy by 15′ is an 11th-mag star—P very slightly N of galaxy by 2′ is a 14th-mag star—SP the galaxy by 0.75′ is a 15th-mag star—NF galaxy by 5.5′ is a 12th-mag star—N slightly F by 16′ is another 12th-mag star
2:07
NGC 3962 (Crt): elliptical?—roundish—0.67′ round—bright core and well-defined halo, trace of a substellar nucleus—N of a pair of 12th-mag stars, one to S very slightly P by 2.5′ and the other S slightly F by 3.25’—NF galaxy by 16′ is an 11th-mag star—N slightly F by 8′ is a 13th-mag star—P slightly S of the galaxy by 7′ is a 12th-mag star
By now, I was hitting the hair dryer between every object, and had caught a few stray hairs in the motor more than once. I knew that my observations weren’t as good as they should’ve been, considering the crud in the sky and—as I discovered—the fact that the secondary mirror’s dew-heater had surrendered to the overwhelming presence of the dew. As I was tearing the scope down, I noticed that the secondary had a ring of condensation around its edge, contributing to the more-feeble appearance of many of the observed galaxies (which I knew should’ve been brighter than they were).
Jeff and I talked for a bit; I hated to leave a clear sky even if my scope was already packed up. He planned to stay as long as possible (although he would later tell me that his secondary had completely fogged-over within an hour of my leaving). I wasn’t as keen to leave a lone observer at Eureka after having seen a bear there last year, but Jeff wasn’t put off by bears; he lived down near Eagle’s Rest, and was accustomed to wildlife wandering through.
So I left while there were still stars visible and Herschel objects waiting to be plundered. It was a better evening quantity-wise than quality-wise, but that was the way things went sometimes.
The Unfrozen Caveman Astronomer 