Saturday, June 23, 2007

glad I went out! (Toronto)

I was really sitting on the fence. I wanted to observe, I really wanted to catch the asteroid Vesta, I wanted to go after from the city some "point sources" (as suggested by Geoff G) but the thought of setting up in the high school's tennis court (with good sight lines) was not attractive, somehow. The back yard was comforting but I would be really boxed in with the houses and tall trees. Finally, at around 8:30pm, I thought, "Stay inside or go out! Make up your mind." OK: the back yard it is.

I quickly set up as Venus was getting bright. I started viewing the second planet at 77x with the Celestron 26mm eyepiece in the catadioptric telescope. Then I flipped in the Meade 18mm climbing to 110x. It was a pleasing crescent. Hmmm, what will happen with the Celestron 2x barlow, I wonder. I inserted it before the mirror diagonal. Wow! Like I was there! OK. Not exactly. But the image was good and when the air settled (it wasn't that bad actually) it looked really good.

9:38pm. 44% humidity. 15°C. When I eye-balled Saturn I swung the tube toward it. I was still at 220 (or so) power. Wow! It popped. Even though it was only 23° up. I observed an incredible amount of detail in the rings and on the planet surface. I was surprised. The air was quite steady and occasionally the image would get rock-solid. The Cassini division was easy to see without using averted vision; it was 2/3 of the way through the rings from the planet. The shadow behind the ring was thin but very crisp. At the equator, the clouds were white. Above, there was a dark tan band. At the pole, lighter, again. The only problem with viewing Saturn at that high a magnification (without an active drive) was that it would drift out of view in seconds. I removed the barlow. Somehow it was less impressive. Still, there was a bright point 3 to 4 ring widths away, to the left.

9:59pm. Spotted a second point near Saturn. Another moon perhaps. Fainter. One ring width away, to the left.

As the planet fell below 20° altitude, the thickening air started to interfere. I decided to move onto some new targets.

10:15pm. I pulled the Pocket Sky Atlas (PSA). I didn't feel like fighting with my big Tirion sky charts, even though I had access to unlimited AC power and could set up my light box. I started looking at the PSA charts for the constellations that I could see overhead. Specifically, I looked for stars marked with a line. (Also had Haas's double stars nearby to verify details...)

Hey, look at that! Regulus, α (alpha) Leo is a double. I viewed it at 110x. The main element was very white blue while the companion is a very faint pale red orangey colour. Widely separated. Tried the 26mm eyepiece for a moment. I estimated they were 1/8th of the field apart in the 18mm. (Haas says they are 176" apart. Main is mag 1.4; secondary is 8.2. Smyth says flushed white, pale purple.)

10:25pm. I popped to Algieba, γ (gamma) Leo. It is a pretty gold-gold tight double. Looks familiar... Ah. I have viewed it previously (noted with a checkmark in double stars). I spent some time with it. The main star is gold with hints of light lime green; the companion is slightly white. (Smyth says bright orange; greenish yellow.)

10:32pm. The Moon is washing out the rest of Leo. So I decided to turn away from this region. Ursa Major is lookin' fine.

10:38pm. Dubhe, α (alpha) Ursa Major. Interesting. I never looked at it before. The main star is bright yellow gold. The companion is pale orange. It is a very wide pair. They are 1/3rd of the field at 110x. (Haas says brilliant orange with a tiny dot of almond brown. 381" apart.)

10:42pm. Ah, what's this, just below Ursa Major. Canes Venatici. The Dogs. Oh! Cor Caroli, the α (alpha) star. I've heard about this... Lovely at 110x. The main star is very white blue and the nearby star is a pale yellow green. They are fairly close. (Haas notes bright white and bluish sea green. 19.3")

I tried for Σ1798 in Ursa Minor. I think I had it but I could not split them at 110x.

I moved back to 5 UMi. The main is gold yellow. The distant companion is very pale. Hard to make out a colour. Mauve? They are about 1/3rd of the field apart at 110x. (Did I get the correct star system? Haas says they're just under 1' apart.)

11:25pm. δ (delta) Boötes. The pair are about a 1/10th of the field from one another. Yellow and pale blue green. (Webb describes as bright yellow and fine blue. Hass says 104" apart.)

11:48pm. The humidity and temperature have been flat. Virtually the same as the beginning of the evening. The Moon's almost down.

11:50pm. With my new, larger astrolabe, I measured the altitude of the Moon. It was 18° up. But starting to get behind the trees in the 'hood.

I was winding down. It was getting late. I started slowly packing up.

The house mates on the top floor of the house in the meantime had turned on every light in every room. It was a little distracting (not to mention irksome—they are so energy inefficient).

While trying to avoid white light directly in my eyes, I shuffled further and further back into the driveway, looking to the south, and over the neighbour's house. And there, just over the peak, where the three stars (β, δ, and π or beta, delta, and pi) in the head of the scorpion. And seeing them, I knew, meant that I should be able to see the Vesta!

I blitzed inside to re-examine the location of the asteroid. Oddly, it was my old astronomy software, RedShift, that made easy work of this. It should have been between ξ (xi) and ν (nu) Sco and to the left of 49 and 48 Lib.

12:15am. I quickly set up the tripod and 7x binoculars. And star hopped to the area. Double-checked. Triple-checked. And saw, in comparing to the chart in PSA, that there was a bright object to the right of SAO 159846 and 159821. The two faint stars below these, SAO 159831 and 159784, both around magnitude 8, were in line with the object, and about the same distance away as they were from each other. The mystery object was same magnitude, around 6, as the top two stars. I sketched the region.

This was very exciting.

My first asteroid sighting.

A great way to finish the evening!


My double star "life list" is updated for these latest (certain) sightings.


Using the Barlow different ways reminded me that I think you get different magnification depending on where you put it in the light path. I will have to investigate this more...

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