I had one of the RASC Toronto Centre's loaner 8-inch Dobsonian telescopes with (1¼") eyepiece kit. I wanted to make better use of this unit, better than I did the first time I borrowed it.
My overall intention was the same as before: shake down a Dob to see if I might enjoy using it. Dobsonians are very quick to set up, pretty easy to transport (to an observing site), very easy to move slightly (to get a better view). It would be easy to tear down. But will I like the push-to effort? The regular collimation? Have I become spoiled by equatorial mounting and tracking?
But that was only part of what I was trying to test or measure tonight.
I started to wonder recently if all the preparation effort I felt I needed to do was becoming a roadblock to ad-hoc observing. Was I getting discouraged by the time commitment required to do a "proper" plan?
So, tonight, I had a "instant" telescope. And I would not spend any time formally planning. In a way, I was simulating a suddenly-clear evening. That it might be a school night but that the skies were suddenly dark and I could observe for an hour or two. Being able to set up in less than 5 minutes, just going out and targeting whatever came to mind, meant that I could get more time at the eyepiece.
Also, short star hops were on the menu. I was planning to staying generally within a constellation or two. Or a region of the sky. No big hops. From the postage-sized backyard, I have good south-west views...
Lastly, operating this beast would give me more experience points... I would be able to better support people with Newts, Dobs, and the like.
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All that said, over the afternoon, I was keeping tabs on the Clear Sky Chart. Also, I checked sunset time (in my Yahoo!Weather desktop widget) and the end of astronomical twilight (with SpectralCalc's online Solar Calculator). 7:24 PM and 9:21 PM.
Curiously, Stu sent out an inspiring note to the listserv at 5:33. He encouraged members to "get out there." While it wasn't a Toronto Centre observing session, even though the Moon would be bright, it was gonna be clear.
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I have no idea what time it was when I was at the eyepiece sticking out the side of the white tube. Maybe 9-ish? It wasn't completely dark as I unload the eyepiece kit and installed the 9x50 finder scope. I hadn't brought out a watch, portable weather station, my palmtop, mobile phone... Nothing to tell time. I could hear the wall clock ticking in the garage.
I was surprised to see Orion still fairly high up. Let's get another look at θ (theta) Orionis.
I cranked up the power. It was with the 6mm Plössl (at 200x) that I was able to finally spot the F star! w00t! It was tricky though, it came and went with changes in the seeing, and changes in my eyeballs.
I crudely sketched stellar nursery and then compared this to the diagram on Jerry Lodriguss Trapezium web page. Good correspondence. Even my rough westerly direction estimate was pretty good. I did not notice, at the time, that it is almost in-line from D to A...
The E star (mag 10.3) was easy to see between A and B, but to the outside. Yet not as far as Jerry's diagram perhaps? Is it moving?
Happily, I spotted the F star (mag 10.2) in-line with A and C but to the outside of C. w00t!
[A happy improvement over my viewing and sketching in February.]
Is it moving too? It seemed closed to C then Jerry's diagram...
With averted vision, the Great Nebula popped. Bright. Intense. Ha. Without an intensifier!
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House mates are goofs. So wasteful. No concern for the environment.
Brian went into his room on the top floor, turned on his ceiling light, which flooded the backyard. Moments later, I heard him out front and he drove away. Hello. Turn off the damn light.
Then Kris did the same thing. Some time later I heard him return and arm his car alarm. All the while the ceiling light was on. Kris has blinds but he didn't shut them. Brian appears to not have blinds.
Chernys had all their lights on. Didn't stop the 'coons from walking all over their roof.
Fortunately, Diane and crew are gone on vacation. Dark. Allowed me to move in the driveway further west than I normally would.
With a small Dob, I could easily pick up, shuffle somewhere different without worrying about alignment issues. Drawing close to the house, I was able to keep in the dark as I viewed the western sky.
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Without a specific plan tonight, I simply looked at the sky (without any eyeglasses) and chose targets. Ah. There's Mars!
The view of the 4th rock, overall, was frustrating. The low power eyepieces (32, 26mm; 38, 48x) in the Dob did not show any detail on the orange disk. At higher power (10, 6mm; 120, 200x) I could see the ice cap but there was a lot of distortion, glare, lower resolution. Lens flare?
Does this 'scope need collimation again? John said he had done it before the OSC star party, before giving it to me. Before 2 trips in my car. But is it off again? Isn't it the case that one should collimate a Newtonian every time before use?
Certainly the planet is much smaller. Smaller every day. Changing fast now. Let's move on.
Gemini was high up. I now had my Pocket Sky Atlas outside. I spotted the double star Σ1187 (Struve) nearby. Rotated my book. Fiddled with the orientation. And star hopped from Pollux.
Arrived at the bright yellow star which seemed to be a very tight double. But even at high power, I could not split it. Is this one of those wide doubles? Sketched the field for further analysis. I noted κ (kappa) Gem. For a moment I wondered if I had accidentally arrived at π (pi).
It was some time later that I realised I was confused. I had thought of going to Σ1187 but then went to κ. I noted kappa but didn't see an obvious double. The sketch however is correct, i.e. I was at κ. I was seeing to mag 11.1 at least.
[ed: Confirmed with SkyTools3. The bright star is κ. The west direction is pretty good. ST3 also shows that A is mag 3.6 and the B companion, at 7.2", is mag 8.2...]
On consulting Sissy Haas's double stars book, I was surprised (and satisfied) to hear her say, "[hard] to resolve." So it's not just me.
Interestingly, Stellarium doesn't show anything either.
We'll count that as a miss.
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The AA batteries inside the loupe leaked! 3 of 4. I discovered this as I went to change them.
The light was getting dim so I popped the cover and found white goo. I dumped the batteries directly in the hazardous materials box in the garage and then scrubbed out the nasty residue.
No major damage fortunately.
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10:24 PM. Just spotted Σ872 (Struve). Near θ (theta) Aur. Dim stars almost equally bright. Easily split in 26mm, they look white?; in the 10mm, colours stand out more although that are very similar. Pale shades. The main is yellow and the companion is orange. I roughly estimated (considering the Newtonian rotated field of view orientation) the Position Angle to be 200 degrees.
(Haas says "bright" stars, "white, nearly equal." Mag 6.9 and 7.4. PA is 216, as of 2004.)
The OneWorld weather station read the humidity as 38% and the temp as 4.6°C. However, it had recently come from the duffle bag in the trunk of the car in the garage...
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Got chilled. In the middle of my back. Damned Windriver jacket. I flipped to my MEC winter coat. I was fine after that.
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11:27 PM. Saturn was showing well. Tethys and Titan were easily sighted. Not to be confused with the distant in-line field stars.
There were moments of wonderful seeing. Breathtaking clarity to the point where I could imagine I was in orbit. At times, the equatorial belt was clearly visible below and above the ring and various bands showing on the surface of the planet. The rings took on stark dimensionality. The 10mm eyepiece is good. Good contrast, fair eye relief.
The 6mm is challenging to work with. It is very small, has very low eye relief, and the field stops are either crummy or you can't get your eye close enough to even see them. Still, this EP is needed. It coaxes out the moons.
I could see Rhea and Dione under the rings. Very tiny points of light.
Every once in a while, I could see another point in-line with the rings and below Titan. That was Enceladus! Wow.
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As much as I wanted this to be casual, ad-hoc, on-a-whim, there are still some things I should do, in preparation, if I can. Rather than fumbling around in the dark, at the last minute, trying to do important things, like find my thick, warm, RASC hoodie, or my leather gloves, or ask the neighbours to turn off their lights. I could have done these things in the afternoon!
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