Sunday, May 24, 2020

cut wood (circles)

With Rhonda's awesome 20-inch double parallel-link arm scroll saw, I cut three 14-inch circles from the 1/2-inch and 3/4-inch plywood. They came out way better than I had expected.

I was starting to plan the cuts for the ground plate when it started to rain.

Earlier today, talking with Tony H, I told him what I was working on. Asked a few questions.

He agreed with my approach of using solid wood for the inner reinforcements. He suggested pine or white wood, 1x2. That's what I had been thinking.

He strongly recommended that I water-seal all surfaces. Indeed. I had been thinking about a finish that mimicked modern Dobs with their melamine or laminate finishes. He suggested a good house exterior paint perhaps an eggshell matt. Then he said a paint-and-primer-in-one would save some effort. All applied a good quality non-foam mini-roller. Right-o.

Tony also agreed with me, that nylon furniture glides will work until I can get some virgin Teflon.

Saturday, May 23, 2020

checked the shots

Checked the camera shots.

Not bad! I was surprised. I can see the sky and stars. Red light streaks everywhere. Yeh.

Found a couple of funny light drawings by Rhonda!

So, I've gotta something to work with...

Checked the frame numbers:

tests 9370-9386 (16)
lights 9387-0143 (~750)
darks 0144-0164 (20)

Checked PhotoPhills again. Using the Timelapse Calculator based on clip length, it looks like the 750 shots at 24 frames per second will yield a 30 second movie! Yes!

cut wood (rectangles)

Dug out my diagram in Visio. Added dimension elements and printed it.

From the 1/2-inch and 3/4-inch plywood I bought last fall, I cut pieces for the Dobsonian base. Four pieces for the cradle (after two tries), the front plate for the rocker box, and the two side plates for the rocker. From scrap I made a couple of retainers. All rectangles.

My new carpenter's square, the repaired work table (with 3D printed part, no less), and inherited circular saw from Mom made easy work of this.

Decided against using plywood scraps for the cradle and rocker reinforcements; I'll get some solid wood for that...

Next big thing is the round pieces. The hard parts.

Friday, May 22, 2020

tried workspace long-exposure

I want to try an interesting "workspace" photo, with star trails above the hedge, and the red lights moving about with me working. Trails / long exposure / time lapse.

Considered the exposure settings from the January southern sky. Doubled the ISO so I could halve the exposure time so to get more shots... 15 seconds?

Programmed the camera and intervalometer. ISO 1600, 20 second exposure with a 2 second gap. Stopped down to f/7.1. That might be too much. We'll see...

Set all that up before I brought the telescope gear from the "airlock" to the backyard. Used the Manfrotto tripod in the west side of the yard. Used the kit lens, set at 18mm, manually focused. AC power from the house.

A solitary bat flew about.

Once the rig was ready, then I set up the telescope gear.

A little after 10, it was clickin' away.

10:45. Rhonda came out.

She asked about the camera. Explained what I was trying to do. She did a rude gesture. Gave her my deep red flashlight and encouraged her to try light-writing. Backwards. Or a star. Moons, clovers! Gave her hints on writing. Helped her with the timing.

She had a go, giggling mischievously. Evil laugh. I would have to wait and see what she did...

1:35. Remembered that I need a couple of those lanyards with the clip. I could have worn my flashlight... for the time lapse.

61 Cygni was great.

2:00. Decided to conclude my visual observing. Tore down and put everything away.

2:19. Checked on the camera. Everything seemed to be working fine.

I capped the lens to shoot darks.

2:25. After getting on the telescope gear inside, I went outside to shutdown the camera rig.

2:35. Back inside.

planets, doubles, planets (Bradford)

Startled the bunny as I moved items to the yard.

Around 9:30, Rhonda came out and said she'd seen a posting by Tony H. He had shared a photo of Venus and Mercury. I thought that cool in itself. I also realised it gave her a visual clue (in contrast to my simple text message prompt). She wanted to see them.

We tried looking around from the backyard but nothing was obvious. As I set up the 'scope, she wandered to the front. A moment later, I went to the front. Didn't see Rhonda but spotted Venus right away, very low, through the trees. Bobbing and weaving, saw another point. Hello! Mercury was just below Venus. Very easy. Nice. Found rho out on the street and eyeballing the planets down the walkway. Unfortunately there was a street light right in the way. Not a great view.

Back in the driveway I found a little pocket between the branches. I was surprised how bright Mercury was. I told rho it was normally pretty challenging to see. We did a quick measurement and it seemed the inner planets were a bit more than one pinkie fingernail apart, not quite two, so a bit more than ½ a degree.

Took in the whole sky. Leo was just going into the trees, Corvus was heading toward the gap, Boötes up high, Corona Borealis, the Big Dipper was straight up or maybe a bit behind me as I faced south.

Horrible seeing (as predicted).
Instrument: Meade ETX-90 Maksutov
Mount: fork mount with tracking motor, tripod
Method: star hopping, with angle finder
OK. Little after 10. Essentially set up and ready to go. Ready to do astronomy, visually observing. Ready to fine tune. Roughly polar aligned. Low power eyepiece installed.

Once again I enjoyed the portable, movable blind blocking the LED street light on Frederick. I thought the blind particularly important on the new Moon evening.

Lots of people were driving around their buzzy cars, goofing around, burning out from every stop sign. Brother.

Launched the SkyTools 3 Pro Visual Sky Simulation on a star in Coma Berenices.

10:12 PM EDT, Thursday 21 May 2020. It struck me as noteworthy, this outing, given my sciatica problems for the last few days. I wanted to do something, get moving, nothing too heavy. I couldn't stand the thought of losing another fantastic clear night.

Tried to figure out the current visible constellations in the south. The head of Hydra. One target was underneath Sextans. Too low. Hydra. Cancer? Slightly right, above Leo. Nope.

10:16 PM. Felt pain in my right shin. Tried to sit carefully. I made a mental note to avoid twisting.

Switched to high priority list items.

Star hopped from ε (epsilon) Virginis [ed: aka Vindemiatrix.].

Noticed the battery indicator was very low on the Sony recorder. Another mental note: watch the level.

Viewed a double near 29 Comae Berenices: HD 110932. Nearly equal stars. Upper one was slightly brighter. I could not get pronounced colours. Every once in a while I thought the bottom star orange. Top one was maybe white or yellow. Quite nice. The SkyTools software said the north star was magnitude 7.2 while the other was 7.7 (not 8.5). Struve 1678. Easy split. Quite wide at this low power. But still attractive. Separation 36.7". Noted a little triangle shape to the east.

10:28. Weird. I noticed that ST3P said the target was "not currently visibile." Huh? I was just lookin' at it.

I returned to 29 Com. I had seen something, along the way.

South of 29, an obvious pair. Wider than Σ1678. About 45 seconds of arc or more, I guessed? ST3P said 65". Oriented south-north. The brighter element was south, below, and would take direct vision. But the secondary was very faint. In the bad seeing, I could barely see it, it didn't like direct. Easy in averted vision. Cool. Stumbled upon SAO 100278 aka S 642. [ed; ST3P said mags 8.6 and 10.0.]

It would be two-in-the-view at lower power.

My comet target suggestion just popped up. Or, a nearby star that I had added, HD 85457. Near the nose of the Great Bear. Hmmm. But I was not really excited about it... I was not expecting an easy hop. I was not expecting a spectacular view in the ocular.

10:36. The ibuprofen caplet gave me heart burn. Ugh.

Began the long hop.

10:44. Rhonda came out. She was bored. I told her I was comet hunting but not satisfied. I was sure I was in the right area but I didn't see anything. Nothing for certain.

I wondered what to show her. What would be good. The Virgo galaxies? The Leo Triplet. I assumed they'd be too dim. Maybe a globular? I chose Messier 3. Whoa. Straight up. Fire trucking hell.

Explained my star hop. Pointed out the starting star, ρ (rho) of Boötes! She couldn't see the screen. I said it was like a lowercase p.

Rhonda thought it a pleasant temperature. I shared that I saw the predicted low was 3°, with a frost warning.

Apologised for the slow progress. Much slower than using a go-to mount.

11:11. Finally landed at M3.

Called Rhonda out.

We viewed the globular. It was granular. A peppering of stars. [ed: Course.] I liked the view.

Got a lawn chair for Rhonda.

Noticed the voice recorder battery level very low. Went inside. Grabbed some AAA rechargeable batteries. And Twizzlers! Movie and treats!

Did some wide-field Mark I eyeball observing.

11:41. Asked Rhonda if she had seen any meteors.

Scorpius rising up through the southern trees. Oh ho! Spotted the Libra! Zubenelgenubi (lower) and Zubenelschemali (above). Verified it with the computer.

Tried to split α (alpha) Librae naked eye. No joy.

Saw Cygnus climbing over the hedge. Lyra and Vega.

23:50. Asked rho if she wanted to see how the focusing Y-mask worked. "Sure." I used bright star Arcturus. The 6-pointed pattern was visible although dim. It worked in the Celeston 26mm eyepiece. Then I tried the Pentax 20mm: it was better. Talked about the behaviour of light.

Onto my experiment proper. I had Rhonda focus perfectly for her vision. Then I examined the view with my eyeglasses on. It was pretty good. I removed my specs and I felt the pattern was off a little. Went back and forth a couple of times.

So I think I can conclude the diffraction changes due to the observer's vision. [ed: I should repeat this with different masks and different 'scopes.]

Then I put in the Tele Vue 9mm. She saw the diffraction rings. Like waves around a stone in a smooth pond. I tried to explain the airy disc. She thought it egg-shaped. And the lines leaning a bit to left. Yep, due to an optical flaw in this 'scope.

She headed in, wished me a beautiful night.

12:12 AM EDT, Friday 22 May 2020. Tried for HD 111959 (STF 1686) in Com. Gave up. They must have been too tight. ST3P said 5.7". Should have been possible. [ed: I've made it to 2.2" in the ETX.] The bad seeing, I thought. Mag 7.9 and 8.9 stars.

Compelling group of stars... At low power. L-shape.

Crazy.

Not good for the programme...

12:31 AM. Oh. Forgot, I had the Oregon Scientific weather station sitting out on the table. Checked. The relative humidity was 33%, wow, air temperature 10.7°C, new Moon phase, barometric pressure dropping, cloudy and raining in 24 hours...

Good one in CrB, not far from ζ (zeta). No other observations... Hold on. The entry in my list was for the AC pairing. I checked the primary entry for HD 139691 aka HU 1167. Bummer. Previously observed. But it was on my View Again list. Logged. Probably for the AB pair at 1.3" with a delta-m of 5! I surmised I had just observed the A and C stars at mags 7.1 and 8.0 with a sep. of 15.3". D should have been visible. E would be impossible.

ST3P showed another star. Hmmm.

I think this needs some big aperture.

Was starting to feel cool. Wanted my winter coat. Wondered what I could take back. Grabbed the liquorice and went indoors. Grabbed my toque.

12:47. Centred on the non-ζ star. [ed: Huh?]

HD 139691. Zoomed in the software. Ah. C, D, and E were on top of each other.

The Object Information magnitude data is very different than the values shown when hovering the chart. To the point where I don't know which star I was actually seeing.

[ed: From Stelle Doppie:

A 8.1
B 9.9
C 8.1
D 9.0
E 8.2

C and D are 1.5" apart. C and D are 14.5 and 15.1 from A. So I think C and D are merging...]

Considered HR 6043. Ah, gee. Not doable in the ETX.

1:02. Lovely. Empty field. Nice pair. σ (sigma) CrB. Looked great at low power. Good.

In Corona, ν (nu) 1 and ν2 are considered a pair, at 360. Bino target.

Next in Corona Borealis.

1:09. I wondered what the transparency was like. Mag limit check. 10.8, 11.0, 12.2, 11.2, 11.5. Good stuff. Definitely in the mag 11 range. Nearly straight up.

Spotted an undesignated pair with Tycho 02580-00742 1.

Viewed HR 6110 aka H V 38. What?! I wondered if the secondary was really faint. Hovering over the star, the software said B was magnitude 9.7. [ed: OI box says 6.4 and 8.8.] So weird. Much fainter. 1 or 12:30 o'clock position. Reminded me of the Blinking Planetary. When I looked directly at the star I didn't see it. Tiny bit east of north. Really interesting pair. In the Pentax.

1:15. Check power. Recorded looked OK. Netbook looked OK. Icon was half-full; 44% remaining; 2-ish hours.

Viewed δ (delta) Boötis. Wide. Easy. [ed: ST3P says 103.8" apart.]

Next. Alkalurops aka μ (mu) works but quite wide. Arguably too wide. Perhaps a target for bins. Very obvious. Bright.

It was interesting looking at δ and μ at the same time, or back-to-back, as they are very similar. Same distance, similar colours.

1:24. A nearby bird suddenly called out. Crazy loud! Hello. You've got a way to go before sunrise...

π (pi) Boo is great. Good for my programme.

Low battery again.

I considered that delta is not a good candidate.

1:35. Changed one battery again.

Spotted HD 175885 aka STF 2421 in Lyra. Near HR 7140 (which I have viewed)... Fainter pair. Half the separation. One or two mags different. Opposed or rather at a 90° angle—approximately—to the HR pair.

No joy with T Cygni.

1:49. I heard a critter munching on the bread I had those by the hedge. Crunchy snack.

61 Cygni was great.

Done. I didn't feel like carrying on. It was 2 AM. I'd be lucky to get in bed by 3. Started shutting down.

2:04. Last condition of the conditions. 36%, 9.4, still dropping, still rain.

Torn down the telescope, all while the camera continue to shoot. Stacked things at the airlock. Took things inside. Took the blind down and stowed it in the shed.

Ho ho! Spotted bright Jupiter in the south-east. Looked for Saturn. There it is! I knew it would be nearby. Awesome. Four planets, pairs bracketing the evening.

2:17. Hibernated John Repeat Dance.

Took the last few items, TV table and carry-all, to the house. Checked on the photo rig.

2:20. Took everything inside.

2:25. Everything (telescope gear) inside.

Found that John Max had restarted. Stoopid out of control Windows updates!

Wednesday, May 20, 2020

imaged 70 Oph (Halifax)

Clear skies. New Moon. Asked BGO to image 70 Ophiuchi again in its 88-year orbit. Aimed at GSC 00434 02340 which puts Σ2272 to the bottom-right.

fast-moving binary 70 Oph in luminance

Luminance only, ½ second subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

This is the fifth year of imaging!

Annual image log:

2016 Aug
2017 Jul
2018 May
2019 May
2020 May < you are here

Forgot to measure the position angle change last year...

Friday, May 15, 2020

hope it's clear for him

Chris messaged me. We caught up on some RASC centre matters. Then he said he was "hoping to nab the last of your spring 2019 and 2020 doubles tonight." Good stuff.

I'm not feeling that energetic in this iffy weather...

Thursday, May 14, 2020

heard from Melody

Melody sent some messages. The first was brief observing notes on her recently viewed doubles."Tau Leo and 83 Leo were fun in the same FOV." But she found Denebola peculiar. Tell me about it. I'm so glad she's enjoying this.

In the second message she attached her reminder checklist. It was very good. Reminded me of when I did a similar thing.

Wednesday, May 13, 2020

refraction refracted refract frack!

Why does refractor always get tagged as a misspelled word? Blogger. Evernote. Stoopid computers.

tried for NGC 4157

Tried to improve on the RASC Finest NGC 4157. But another satellite went through! First attempt with BGO was 24 Apr '17 and the last was 22 Dec '17. Gah.

helping at RASC TC meeting

I'm on duty for tonight's online Speaker's Night with RASC Toronto Centre. We're hearing from Dr Elaina Hyde on What Happens when Galactic Evolution and Data Science Collide. Turn in on the RASC TC live stream... Programme starts at 7:30 PM EDT.

Binary Universe: good to go?

I received an email notification from the RASC national office. The new Journal was out!
cover of the Jun 2020 Journal of the RASC

The June 2020 edition has a number of interesting articles. There a piece on outdoor lighting. A member discusses his Herschel 400 observing project. There's an article on the recent kerfuffle over Betelgeuse. And a piece of using "classic" amateur telescopes. Lots of neat stuff to read.

In my Binary Universe column I talk about the Good To Stargaze products, the web site and the mobile app. I specifically downloaded the Android tool, version 2.2.26. The GTS products are handy in that they give a high level synopsis of sky conditions. Free access gives the evening forecast. A paid subscription shows the forecast for the next 7 days and allows favourite location profiles to be saved.

Tuesday, May 12, 2020

answered some YouTube questions

Andrew told me about a new question on my measuring double stars YouTube video.

from Lab Geek:
I’m in the Southern Hemisphere in Australia, I’m interested in observing double stars, I managed to piece together a spreadsheet from this presentation I’m wandering will the calculations differ between the Celestron and Meade astrometric eyepieces? Also does the Sidereal time factor change?
I replied:
Answer 1:  I think you might have to do some specific calculations for the eyepieces, yes.  That's for a couple of reasons. The Celestron (baader) and Meade are different focal lengths. Given the field of view are different sizes, you will get different drift times.  But the time you get will determine the scale for your eyepiece.  Also, the linear scales between the two are different, one has 50 units and the other has 60.  So, again, that may affect your spreadsheet.

Answer 2:  I do not think the sidereal time will be an issue.  You'll simply need your local sidereal time when logging your measurements.
§

Then I discovered I forgot to the article link! Sheesh.

Monday, May 11, 2020

xi Boo round 2 (Halifax)

Back on 22 May 2019, I imaged ξ (xi) Boötis for the first time. It is a binary with a 151+ year orbit. Maybe through annual images I'll be able to see the orbital motion. This is the year 2 shot...

double-star xi Bootis in luminance

Luminance only, 0.5 seconds subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; east is left. Centred on SAO 101256.

I'll try blinking it but I suspect it will be difficult to detect any movement at this stage...

Saturday, May 09, 2020

fielded a question

James, the RASC Observer's Handbook editor, forwarded a message to me. It came in to RASC national via the "ask an astronomer" form. It was triggered by the recent talk I did on double stars. Joel asked:

I am an amateur astronomer in Australia, I recently saw a talk on youtube by Blake Nancarrow about observing and measuring double star systems and contributing your data to science.  I was wandering where I can submit my data for my observations?

Cool.


§


I crafted a response informing Joel of the JDSO (in USA, the one I have used) and the Webb Society (in the UK).

he's makin' a list

Chris and I chatted about some good sources for solar system data. Then he said, "I scrolled back on the forum and grabbed your double stars for Apr and May 2019 for a look at." He's hoping for clear skies. Me too. I think it's cool that this forum discussion is becoming the building blocks for some.