Observation Report, 05-25-2018, Tech Terrace Park

Who showed up?

Steve Maas 10×50 binoculars
Richard Craig 102mm Maksutov
Me Zhumell 8” dob
Tom Heisey TV 101 Nagler-Petzval
Gary Leiker 12” Orion Intelliscope
Mark Smith self
Scott Harris & Lesley Chapa, selves

My hoped for big turnout for the end-of-school fizzled without a student, and we put on a public star party for ourselves, but that was okay. I learned a few things in the process of observing and enjoyed the camaraderie in the ancient practice of stargazing, joining us to the Hershels, Galileo, the Romans, Greeks, Mayans, Han Dynasty, Jyotisha, Egyptians and Sumerians, doubtless before.

I arrived as Richard Craig was setting up, and Steve asked how I could actually get there on time, so often late. But I started setting up about 9:15, skyglow in the west from the sun just below the horizon. Venus was already bright in the west, so I used her to setup my Rigel and 30mm RA finderscope. She was a nice sight in the Pan 24, a gibbous, featureless moon on the opposite side of the sky.

With everything lined up, and now Pollux and Castor coming through the deepening dusk, I tried M35 in the scope, very near Venus. Found it, but, boy, was it disappointing! Gosh, the contrast was all gone as the stars tried to break through the creamy background. Turned me off completely from wanting to look at open clusters for the rest of the evening. For sure, my hoped for quartet of M35, 37, 36 & 38 dissolved like the twilight, a set one cannot observe with any satisfaction in late May. Oh well, live and learn.

Being in the neighborhood, I split Castor for grins. It was pretty tight and required the 11mm Nagler at 112x for a clean, if somewhat tight split.

So with twilight still in the sky, I decided a good look at the moon would be okay, blinding, but at this time of the evening, okay. And we were not disappointed about the blinding part. Luna was bright and searing, making whichever eye one used to observe her utterly useless once you’d backed off from the scope, overwhelmed by the photon flood she just poured into your cornea. But for that flood, a wonderful sight of the huge ray craters Tycho and Copernicus dominated her rugged terrain south and north of the lunar equator. Still some shadows on Kepler, and the terminator was awash in detail. And awash is the right term, since the thermal stability of the evening at that point was quite heat bedeviled. Having reached 99 degrees Fahrenheit officially, the sky was wavering under magnification, and the moon demonstrated this better than anything else in the sky.

Tom Heisey had setup his TV 101 F/5.4 on a Losmandy EQ mount by that time. It was interesting how much better it seemed to take the heat. The images rippled in it, too, but they somehow seemed more stable. Perhaps the extra-wavery images came from tube currents in my tube? I didn’t use a fan on my Z8, so was subject to the whims of the environment, but the scope had been stored indoors, and the temperature, though a little hotter, wasn’t a whole lot warmer at the Park than in my home (80* to about 90*).

And this thermal stability of the refractor over the images in my Z8 was even more demonstrated on Jupiter. Although by the time we got to Jupiter, Gary has his 12” dob set up. But I jump ahead of myself.

There were a bunch of double stars to crack, and after Castor and the moon, I began cracking them. Kappa Geminorum I just flat missed by not checking my observation list. Duh! But I nabbed Algieba, Gamma Leonis, easily enough. Again, I needed 112x to split it, but didn’t really like the view at higher powers, so a tight split would have to do for this yellow-white pair.

Cor Coroli was next, and almost straight overhead, so in the difficult “dob hole” region of the sky that made getting it into the eyepiece more challenging, but I managed to steer the scope onto the target with sufficient effort, and this nice white-blue primary and white-green secondary was pleasing to the eye.

Iota Cancri proved to be the most appealing double of the night, with its yellow primary and blue-ish secondary a striking pair, and the most attractive double our moon drenched sky would afford.

Because Mark, then Lesley and Scott all showed up later, I made two tours of the better naked eye doubles, and so made two passes at Castor, Iota Cancri, Algieba and Cor Coroli. Like Ella Fitzgerald sang, “Nice work if you can get it, and you can get it if you try.”

We tried to get M3, but it was simply too close to the bright gibbous moon, and all efforts produced washed out skies with no globular in sight!

I went after Izar, Epsilon Boötes, and discovered more heat issues. With its white primary and blue-ish secondary, it could be split at 176x with the 7mm Nagler, but the scintillation of the primary under the high power and thermal issues, made the split temporal at best, with the primary morphing in the eyepiece to merge into the secondary most of the time, with only momentary glimpses of the secondary, when the image would momentarily settle down. That was disappointing, but a characteristic and bedeviled the splitting of Porrima, Gamma Virginis,too, and in exactly the same way.

Our one good DSO for the evening turned out to be M13, the Great Hercules Cluster, and “Great” it was. Nothing like under a dark sky in the country, mind you, but at least it was interesting to look at, with actual characteristics observable, especially in Gary’s 12” dob. This scope produced, by far, the best image of M13 of the scopes on the field. My Z8 did a reasonable job under the circumstances, but the 12” dob with Gary’s 13mm Ethos (and 17mm Ethos) produced the best image of M13.

But the most intriguing body in the sky this evening was, of course, Optimus Maximus himself, Jupiter Rex. Beautiful and resplendent with creamy stripes and brown bands, I don’t think the Great Red Spot was out, but all four Galilean satellites sprawled flanked the great King. And on Jupiter I made some interesting observations from the various scopes. First, having a tracking mounted, well made refractor, is hard to beat on planets. And the only scope that could was Gary’s 12” dob. By sheer force of photons, yes, Gary’s view was the best, but not by a lot, and honestly, Tom’s TV 101 put up a more effective view, using my TeleVue DeLite 3 & 4mm eyepieces, of Jupiter, than even my Z8. This is not to say my view was inferior, exactly, only that the thermal issues that bedeviled my double star efforts continued here, and even though the refractor’s image also rippled with atmospheric heat waves, the scope itself wasn’t adding to the problem, and this did not seem to be the case with the dobsonians. But at 12”, the sheer number of photons a 12” mirror could bring to bear on an on-axis target like Jupiter overwhelmed the other considerations, but it took that much! The little 4” refractor really could keep up, and not having to manually track was big advantage, especially under the heat soaked circumstances.

I finished by splitting Algorab, Delta Corvi. I like the Star Splitters descriptions of Delta Corvi, a fairly wide pair with enough color difference to give the effect of a star and planet combination. Indeed, I see a yellow-white primary and a brownish white secondary, planetary indeed.

It was late and I was very tired. I packed up, shook some hands and drove towards the home, fortunately not very far away.

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