Monday, June 16, 2014

out back with the Dob (Mississauga)

Friend's 8" f/6 Dobsonian again. In the back yard this time. Near the fence. Patio table was the main station. Used the little wood TV table so to have the computer right beside the 'scope. Big Dipper over the roof.

15 Jun 2014, 11:03 PM. That was the fastest ever! Using the SkyTools 3 Professional "hopping" method with the Visual Sky Simulation three-panel display. I turned the computer screen 90° while I looked through the finder scope. And it was still a little hard to see the stars in the chart. But I could tell I was in the correct area in Ursa Minor.

Beside an hourglass of stars, with HD 151043 at the centre. Neat.

11:06 PM. Looked again at the multi-star system HR 6267. The first impression in the 40mm eyepiece was that it was one star. Put the 26mm in. Then the 9mm. Many faint stars visible now.

11:10. Ah ha. The faint, magnitude 11.5 star to the north is C. Toward TYC 04572-1278 1 (v10.5) and TYC 04572-1255 1 (v11.3).

11:12. Couldn't see B. Collimation off a hair. Slightly lopsided diffraction rings.

11:14. Tried again. Couldn't see B. It is fainter than C, according to the computer. Kept trying. Trying to tease it out.

11:20. Noted TYC 04572-1517 1. Saw it before, to the north-west. Faint star, magnitude 12.2. Tried the 4mm ocular. No joy. Could see the airy disc, the diffraction rings. Thought of water drops and ripples. But no second star.

Noticed, when zoomed in on the chart, that B was bright. Ah. So, once again, the Object Information box data was misleading. The atlas says B is mag 6.1 while A is 6.0. Only 2.6 seconds of arc apart. I was frustrated reading that. I can easily split stars this low. That's well within the capabilities of the equipment...

I thought, if this is on my multiple-stars-observing-programme list, I don't think this is a good one... [ed: It is.]

11:27. Damn. Noticed some high thin cloud in Ursa Minor. Seemed to be thicker in north-east.

11:29. Spotted a satellite heading north-north-east. Not as bright as Kocab.

11:38. Next target near the neck of the dragon. Wow, super fast again. Must be getting used to Greg's Way.

11:40. First impression, again, with the 26mm, it looks a single star. A little triangle to the east with HD 160657 as the brightest of the three. Neat. And there is a little faint double to the south...

11:42. Wow. ST3P says the C star is to the south, between the triangle and the wide double. OK. So, widely separated, very orange, much dimmer, A is yellowy. Took more looks at 26 Draconis aka HR 6573. Again, if this is on my double star candidate list, it's probably too hard as well: C is way too faint; B is way too close. [ed: It is not. But it is in the "fast movers" list.] Saw the star GSC 04199-1007 (not visible in the Context Viewer). ST3P says it's 14.2 but it's poor data. Saw GSC 04203-1285. It was easy, it's mag 12.9, to the north-west. [ed: Haas reports on the A, B, and C stars. Says A is bright yellow. Shows AB at 1.6" separation. She must have caught it at apastron. ST3P says they are currently 0.55"!]

11:52. Still wispy clouds in the way. Ugh. Mozzies as big as Cessnas. Going after my knuckles.

11:58. Holy frick. Made it very fast toward μ (mu). Actually landed in a patch of doubles...

16 Jun 2014, 12:00 AM. HD 155674. A tight pair, in the 40mm, orange and blue, faint, very similar brightnesses.

HD 156162, further east, brighter primary, ST3P says it's a triple, I saw the C star no prob, C is maybe 1 or 2 mags dimmer. [ed: ST3P says 2-ish.]

HD 234404 is a single star, orange? Which is beside HD 234403, yellow? "3" is a super tight double, below my career limit. "4" and "3" proper form a faint pairing, nearly equal brightnesses, although they are not related (according to SkyTools).

12:09 AM. Onto Arrakis! Two touching stars, with 26mm (i.e. 47 power), yellow. In the 9mm (now 135x), split. A and B are the same colour, same brightness.

12:25. Nope. Could not pull out, C star. Even though I could coax out GSC 03890-0488, 13.3 mag (poor data).

Went back to HD 156162. No problem with C star; could not split out B. Damn. Same brightness as C but closer in, obviously. 2.7". Should have been possible...

This whole area is neat... Anywho. Next!

12:46. Bull's eye! Landed on η (eta) Corona Borealis. Boom.

Saw KZA 86 to the south, obvious. A faint pair, mag 11 and 12 stars.

12:56. Crazy. That was tough, spotted Σ1973D, a magnitude 13.0 star, inline with TYC 02563-0766 1. But could not split B (v5.9). A is mag 5.0. They are currently 0.67" apart (another fast mover). OK. Maybe not tonight. But C? So frustrating! Could not see C (v12.6).

1:10. Viewed δ (delta) Cygni. Also frustrating. Could not see any of the elements. What? Why?

Possibly I saw C in a moment of good averted. Very difficult... Mag 12.0.

Realised I had been at it for a while. Came in for a snack. Sat on the couch. Ahhh.

1:39. Notice the light of the Moon on floor. Oh. Right! That's why the sky was going away... It was pretty high in the sky but I was still sheltered from it behind the tall trees.

Suddenly lost my momentum.

Checked the current conditions at the Environment Canada web site. Partly cloudy, 14°C. Observed at Toronto Pearson Int'l Airport. As of 1:00 AM EDT Monday 16 June 2014. Condition: Partly Cloudy. Pressure: 102.0 kPa, rising. Temperature: 13.9°C. Dewpoint: 9.0°C. Humidity: 72%. Wind: E 6 km/h. The forecast: Increasing cloudiness. 60 percent chance of showers in the afternoon with risk of a thunderstorm. Wind becoming northwest 20 km/h late in the afternoon. High 24.

It was never fully dark this evening, like yesterday. Twilight ended at 11:23 PM but the Moon rose at 11:03.

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