Tuesday, July 17, 2018

catching up

Trying to catch up on some recent observing:

Last week I went to Stanford to support the Tech Trek science camp star party. I brought my 10-inch travel scope. It was 90% cloudy and we thought there would not be anything to look at, but a gap opened and we could see Jupiter and Saturn, which satisfied the crowd. I could see some doubles in Scorpio. Just as I finished packing up lightning flashed in the west, and a few moments later it started raining – lucky I was all dry. There’s another star party for this week’s set of campers tonight; luckily it will be clear.

Saturday night I went with Bob to his property in Willow Springs. The forecast was variable, with possibly cloudiness – fortunately it turned out to be a very good night, even if transparency wasn’t perfect. We arrived at sundown and I helped clear some weeds from around the containers. I brought my 10-inch Springsonian and spent the time scanning the Milky Way star fields and its dark nebula. It was really amazing to see the transitions from bright star field to less bright areas screened with some dust and finally full on defined dark nebula. The scope is perfect for it; I only regret not bringing binoviewers since I think it would have really made for dramatic scenes. I swept up many globular clusters, especially near the horizon. I also looked at M101, M51, and M31 one right after the other using the same low 37x magnification – and was amazed at the difference in scale – M51 especially appeared very small compared to M101, and M31 of course extended well beyond the field. Usually I’d up the magnification on the smaller galaxies to have a “better” view but it was really cool to see them offset like that. We drove home around 2am and really next time I need to sleep over, I don’t like driving tired like that.

Sunday night I had some time to observe in the back yard, having some naps during the day. Started out with a nice moon/Venus conjunction which I viewed through 7x35 binoculars; nice earthshine though I could not see Venus’ disk. Unfortunately it was behind the yew trees so I could not use the telescope.

I happened to view Jupiter first since I was planning to observe doubles in Libra, and it’s lucky I did since Io was just finishing its transit and was erupting from the limb when I looked. I watched as it separated from the limb. Its shadow was near the center of the NEB, just passing a dark barge in that band. Three bands visible in SEB but no GRS. Large turbulent festoons in the equatorial zone.

I proceeded to doubles, seeing 6/10, 553x mostly:

BU 117: Well split, 0.5 delta mag, ~1.5”. Having some trouble to star hop with just a 50mm finder. [AB seen, AC very faint and wide.]
14H 31M 19.74S -15° 38' 19.5" P.A. 74 SEP 1.5 MAG 8.44,9.36 SP G5V DIST. 42.37 PC (138.21 L.Y.)

HU 140: Seeing not quite good enough, need more darkness, and it’s near Jupiter. I can see an elongated smear – know it’s double but not quite resolved. AV brightens but does not split.
14H 32M 32.68S -13° 00' 14.1" P.A. 196 SEP 1.4 MAG 9.46,10.08 SP G1/2V DIST. 112.49 PC (366.94 L.Y.)

5 Lib / HLD 20: 6.4 ,10.1, 3.1” Light orange star, went up to 800x but can’t see B – a halo around it, transparency might need to be better.
14H 45M 57.78S -15° 27' 34.4" P.A. 249 SEP 4.7 MAG 6.48,10.10 SP K1III DIST. 444.44 PC (1449.76 L.Y.)

BU 346: Easy, well split, yellow-orange stars, ½ delta mag.
14H 48M 31.71S -17° 20' 24.4" P.A. 277 SEP 2.7 MAG 7.48,7.92 SP G1V DIST. 44.5 PC (145.16 L.Y.)

BU 119: Very like BU 346; well split near ½ delta mag yellow stars, 2.5” [AB seen, two other pairings, faint and wide.]
15H 05M 31.91S -07° 00' 48.8" P.A. 274 SEP 2.4 MAG 8.09,8.76 SP G0 DIST. 47.6 PC (155.27 L.Y.)

STF 3090: Notched to hairline split at the best moments. Faint pair, tough. Seeing not good enough to go above 553x. [AB seen; AC fainter and wider.]
15H 08M 42.97S -00° 58' 50.4" P.A. 286 SEP 0.6 MAG 9.09,9.34 SP G0

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