Monday, September 20, 2021

taught Stellarium intermediate

Delivered another Stellarium level 2 course. Good crowd. Good questions. My mount behaved just fine!

Sunday, September 19, 2021

posted Sep '21 doubles list

Prepared my double star "bulletin." It is a short list of suggested targets. I shared this on the RASC Toronto Centre forum. I post here for all.


School's back in, sorta. Summer's over, sorta. One thing for sure: the Moon is back, big and bright. And that means you need to shift to planets, variables, and double stars.

Here's a short selection of doubles and multi-star systems from my life list, ones I find impressive and interesting.

staralso known asalternate catalogue(s)
β CapΣA52, Dabih, 9 CapSAO 163481, HIP 100345
ε EquΣ2737, 1 EquSAO 126428, HIP 103569
HD 177904 AqlΣ2449SAO 124265, HIP 93822
HD 203320S 786 CygSAO 33323, HIP 105298
V402 LacHJ 1735SAO 51698, HIP 109354

Have a go. See if you can split them and detect colour. I hope you'll share your discoveries.

Blake Nancarrow
astronomy at computer-ease dot com

Notable double star designations:
Σ = F. Struve, STF
ΣA = Struve Appendix I, STFA, Σ1, ΣI
β = Burnham, BU
HJ = John Herschel

Saturday, September 18, 2021

made a new calculator

Made a new, updated, hopefully easy-to-use online spreadsheet for Melody to use. It's basically fill-in-the-blanks and it should yield a good separation value for a double star.

It's pretty snazzy.

Onboard instructions and notes.

Constants sheet for the Earth's rotation rate and the sidereal time factor.

Supports variable Linear Scale divisions, say 50 or 60!

Prompts for a dozen drift times, taking the average.

Prompts for the star's declination, so to compute the speed of the sky.

With that, the Scale Constant can be determined (per my proper formula).

Supports four scale constants with and without magnifiers and reducers.

Finally, prompts for double star pairs and their separation in tick marks on the Linear Scale.

Computes the true separation or ρ, rho for a dozen pairs.

Hope they like it...

helped Bruce and Melody

Chatted with Melody and Bruce about their new Meade Astrometric eyepiece. Told them to not use Meade's faulty instructions. Explained that the speed of the sky was a factor. Demo'ed the process with my new spreadsheet. Readied to invite them to the shared file...

Friday, September 17, 2021

did some math

Another interesting journey...

I started a round of research to learn or verify how to measure double stars with the Meade Astrometric ocular with its illuminated reticule and its central Linear Scale with 50 divisions.

My experience is with the Celestron or baader planetarium Micro Guide (now discontinued) with 60 divisions. 

I had a bad feeling that my method and separation calculation would not work. I wanted to help Melody learn how to use hers but feared my technique would not apply.

"Let's start from scratch," I thought. 

Did some broad internet searches.

Landed in a Cloudy Nights thread started by Jeremy Perez no less. He was trying to learn his Meade Astrometric eyepiece. Perez developed his external protractor. People recommended Tom Teague's method and Bob Argyle's book. But in the end, it didn't reveal to me a formula.

Then I found a thread in the Stargazers Lounge. Davey T asked how to use his Meade (though he showed a reticule image for a Celestron) back in the spring of 2015. William aka Oddsocks gave a procedure referring to a star at zenith. A day later he backtracked. On reading Qualia's notes for a Micro Guide, he realised his instructions were wrong. But he had simply relayed the notes from Meade.

It is strange how you read something from a "respected" manufacturer and believe it must be correct...  I realised the published linear scale calibration method in the Meade document is garbage!

Oh my.

The Meade document is useful in other details but the linear scale calibration method can be ignored unless you are living on the equator

So I still did not have a formula.

But now I was getting more nervous for Melody's sake.

I read Qualia's blog post on measuring doubles and Jovian moons with the baader Micro Guide. Some pretty good notes.

Finally, I found a formula for calculating the drift’s scale constant.

S.C. = 15.0411 * T.avg * cos(Dec) / D


  • S.C. - Scale Constant
  • 15.0411 - Earth’s rotation rate per hour in degrees
  • T.avg - the given star’s mean average drift time
  • cos(Dec) - cosine of the star’s declination
  • D - number of division on the linear scale

I compared this to my formula:

ρ = D * T.avg * SidFact * cos(Dec) / 4


  • ρ - separation in arc-seconds, rho
  • D - divisions or ticks on the LS, in decimal form
  • T.avg - average drift time in seconds
  • SidFact - sidereal time factor or 1.0027379
  • cos(Dec) - declination of the star, in decimal form

Some marked differences that unnerved me. Oh boy.

Couldn't seem to find the source for my formula...

Still, there seemed to be something going on here. I could not see it at first... But after a lot of head-scratching and noodling and staring and some home-made spiced rum, I realised what it was.

The 15 (and change) value divided by 60 divisions gave 1/4 (close enough from an aeroplane). That was what I was using in my formula! Whew. They were essentially the same. That was a big relief. So I made a new universal formula considering everything.

S.C. = ( RotRate * T.avg * cos(Dec) * SidFact ) / D

And then you multiple that by the counted ticks on the scale to get ρ, of course.

I really like this new formula since it will work with any reticule regardless of the divisions and as it integrates the sidereal time factor too, which I also cross-checked.

That's produced by dividing 86400 (regular day in seconds) by 86164.0905 (a sidereal day in seconds).


Along the way I could not find an official PDF on the Meade site for the ocular. I could only find it on one of those suspicious manual sites...

But I finally saw it with my own eyes. Step 4: Aim the telescope at or very near (within +/- 5°) the zenith (perpendicular to the ground).

Later they said to take three timings. Ugh. More bad advice.

And there it was in writing, after the step-by-step procedure. Stars at or near the zenith move across the sky at 15 arc seconds per second (sidereal rate).

No. Wrong. Completely wrong.


Oddsocks had called it. The true separation formula provided, ( T.avg * 15 ) / 50, would only work for observers at the equator.

So, again, the formula I made should be used:

S.C. = ( RotRate * T.avg * cos(Dec) * SidFact ) / D

This tells you how much real sky is between the tick marks on the Linear Scale.

Sorry. More work. And some trig. Sorry! But you'll get rather accurate results. I tested it in Stellarium with the Meade reticule view.


In follow-up messages with Melody, I learned that the instructions in her eyepiece box were like the ones I had stumbled across. New eyepiece from a 2021 sale with old bad instructions. Wow. It's amazing to me is that after all these years Meade hasn't fixed it or issued new information. Terrible.

tried rho Ori in a small 'scope (Bradford)

Back inside after the brief back yard observing session.

The plan was to spot the B companion to ρ (rho) Orionis, while I had a clear patch. I was concerned the double, in the new observing certificate program, might be too difficult for an observer with a small instrument. 

But I saw it.

It was challenging to be sure in the Meade ETX 90mm.

But it was definitely there.

With the Tele Vue 9mm Nagler Type 6, it was well beyond first diffraction ring. It was even visible in the old Celestron Plössl 26mm eyepiece. Detectable. The best view was with the Pentax wide view 20mm ocular.


I spotted C too.

B was to the EEN or EEEN, opposite HD 287611, very tight, much dimmer.

I viewed this double a bit before the meridian. Star hopped from Bellatrix. 

Pleiades up high.

Winter is coming.

Tempting to continue but... I was too tired.

I thought rather good seeing, average trans. But damp. Very humid. The grass was wet.

Pulled the Clear Sky Chart. Cloud cover: clear; transparency: above average; seeing: excellent; Moon: -22°.

Clear Sky Chart for Friday morning

Pulled the weather data from EC. Current Conditions. 11°C. Observed at: Egbert. Date: 5:00 AM EDT Friday 17 September 2021. Condition: Not observed. Pressure: 102.2 kPa and falling. Temperature: 11.3°C. Dew point: 10.8°C. Humidity: 97%. Wind: ESE 4 km/h.

So, a good experiment. 

No modifications needed...

Wednesday, September 15, 2021

suggested peeps

Chatted with Tony on some Nom Comm candidates in the Toronto Centre. It's that time of year...

heard the reticule eyepiece arrived!

Melody shared with me that her Meade Astrometric eyepiece arrived.

That was quick! From the UK. 

Then she said, "Now to learn to use it!" Indeed, I encourage her to watch my double stars measurement video... 

But then I had a sinking feeling! Would the formula in my video and companion notes work?! The Meade as 50 divisions in the Linear Scale while the Celestron/baader has 60. Oh oh. I had a feeling that would affect things. 

This kicked off a round of research...

Tuesday, September 14, 2021

heard of the successful test

Ask Jo if he could test our uploader service in the Linux environment. He tested in a light-weight browser on Zorin Linux. Said it worked like a charm and was fairly fast.

checked another vid

Reviewed another video for the RASC Toronto Centre A/V team.

processed trainees

Did some Stellarium training processing in preparation for the level 2 gig on 20 September.

asked for a DDO account

Submitted a request to national to reimplement an account for the Dunlap Observatory chair. Without it, she cannot access the RASC Toronto services...

fielded a query about a Moon photo

Yet another query came in via the RASC national web site observing form.

This time the person felt that in a photograph of the Moon they captured a shadow cast from another planet. 


I offered to look at the photo.

Unfortunately it was a shakey, hand-held, zoomed out, out-of-focus, low resolution, overexposed shot from a smart phone and saved in JPG.

Just an artefact, I argued.

Keep trying.

the very first one

Received the first-ever fully-completed RASC Double Stars certificate application! This just made my month.

chatted with the chair

Chatted with chair of the David Dunlap Observatory. Dealt with a number of open items. Curious of the status of a camera. Curious if I was needed. Recommended some other contacts for receiving notifications, for better coverage.

Monday, September 13, 2021

rejected some members

Issued rejection notices. Half dozen. General members continue to get confused and try to join the operational committee RASC Obs Comm forum workgroup thing.

relayed the good news

Shared some happy news with the RASC national team.

Harry from Uganda had found his Explore the Universe certificate and pin.

In fact, it had arrived on 8 April but the mailman never informed him!

Another loop closed.

proofed column

James asked, on the 9th, to review my Journal column draft, and respond before the 13th.

But Chris had my latest images. In his iPhone. In Richmond Hill. And he was at the CAO over the weekend. So I nudged Chris early Monday morning... A tad late.

I noted the wrong image was used for Figure 3. Sent it again.

And I provided an updated image for Figure 1.

Finally, I reworded some text in the Bits and Bytes section to be past tense.

picked up Teflon

I diverted during the drive home. Picked up purchased Teflon pieces. Heavy!

Sunday, September 12, 2021

received more silica

More silica packs. Yes! My sister continues to put these aside for me. Thank you, thank you. Now. If anybody needs some...

Mask of Constellations

Received a little gift from sis.

An Ardene face mask.


With constellations! Cool!

reviewed her last observation

Melody shared another double star observing log page.

She said it took two early mornings to observe the B star... "very tiny, couldn’t see any colour..." Kept checking if she was on the right target.

I reviewed her notes and sketch for ρ (rho) Orionis, cross-checking in Stellarium on my Mom's Macintosh. Too bad SkySafari does not show it! Sheesh.

She got it!

At 40 degrees elevation, she viewed through 2 air masses. That said, the target at 45 degrees was about has high as it would ever get, for us.

The main issue with the dim companion star is that it is 4 magnitudes dimmer than A. So the primary star would overwhelm the view.

I also felt she tagged the C star in her sketch but pointed out it was the first one, not the second one, to the south-east.

It is a challenging target.

She made a remark about whether it would be visible in a small 'scope. I took that to heart. I only observation had been with a C14. I'd try with my 90mm later...

Her last required observation!

Friday, September 10, 2021

in the line of fire?

No pun intended...

Received a query from a person from the general public via the Observing Committee web page form.

Subject: identify rock/metal fragment


The person said they had found a small fragment of burnt metal/rock in their backyard lying on top of the grass and assumed it to be space debris. They doubted it was a meteorite because it wa relatively light. It was very hard and she could not break it. She wondered if it was from the fireball seen on August 22 from Crystal Beach.

I responded. I declined an offered photo. I shared a link to the University of New Mexico web site, into the Geology department. Encouraged her to read the information there. I also told her that if it really is from space, she should immediately protect the object from contamination by bagging it. I also suggested taking it to the geological or geophysics department of a local university.

more IT support

Helped Chris some more with IT matters at the CAO. He rebooted the main router and lots of things started working better. Doesn't make sense but anyway. Then Backyard EOS wanted credentials so I shared those. It said it all worked. Most importantly, the network speed from the SLO was improved.

learned DSG history

On 7 September, Mike S filled out the contact form for the RASC national Observing Chair. He had a query about the Deep Sky Gems program.

Mike noted a change made to the list in the summer of 2020. The editor's note states that Levy 402 was introduced in place of Levy 226, however the numerical listing and detailed object tables both show Levy 226 present, and Levy 225 deleted. He did not see an update regarding this apparent conflict of information. He asked for some clarification.


I was pressed for time so I quickly acknowledged the receipt of his message. 

Today, I followed up with a detailed reply on his interesting observation.

I shared with Mike that in late-July and early-August, I started a dialogue, with the editor and content owner. I had concerns with the Deep Sky Gems list. It was when I personally considered pursuing the DSG program and did a deep dive that I started to see a number of issues.

In fact, on 1 August, I pointed out this very matter, 225 was missing, 226 remained. And curiously this specific question had never been answered! I did do not know what was intended but guessed it a simple transcription error. The editor meant to say that 225 was replaced by 402.

I thanked Mike for drawing attention to this matter in the Handbook. It needed to be reported and noted in errata documentation...

Then I went on. I told Mike I was anxious about list changes occurring every year or so and I had raised the matter with the Observing Committee. Others were not aware that this was happening. In particular, I wanted to know if it was affecting him. I was concerned that if he was working through the observing certificate that periodic changes might throw off the member.


Mike replied and shared his experiences with the DSG program.

Since first approved, a total of fourteen objects have been changed. That was an eye-opener.

He recommended that changes in the Observer's Handbook be reported by the Observing Committee when they report to National Council so there is an official record. And be included in a RASC Bulletin. I absolutely agree. He noted that if the OC is not being informed of changes being made, they should be. Yes.

These changes challenged him since 2010.

He also noted the original introduction stated there was only one object that overlapped with any other RASC lists. As he worked on the list he found three additional duplicates, one with FNGC and two with Deep Sky Challenge. These were reported and subsequently removed and replaced with four new objects in the 2013 OH. Eight of the fourteen changes mentioned above.

carpet yanked

He agreed with my comment that an observer could be thrown off if changes are not clearly communicated. It would be beyond frustrating to think one completed the list to only be told one had to observe new objects. Yes, exactly what I'm trying to avoid.

Finally, he noticed the PDF list on the web site was outdated. A to-do item for us.

All that said, Mike said that he was really enjoying this program and wanted it to succeed.


I thanked Mike again. I appreciated the fantastic historical perspective. It would really help me out going forwards.

Then I made my key point. I made it clear that the Observing Committee is NOT going to make an observer go and observe new things if they worked from an older list. He definitely would not have to redo anything!

pitched some training

Sent a message to the level 1 graduates on the waiting list. Told 'em that we were planning to deliver a Stellarium intermediate level 2 course on the evening of Monday 20 September.

he let me in

Chris shared his double stars log spreadsheet with me. We disagree on colours for some targets. I wanted to collate his and Melody's observations ahead of updating the Supplemental document. Compare against mine...

learned how to script

I was bored so I taught myself how to do scripting on SIMBAD data.

I pulled the B-V values for all the double star targets in my RASC observing program! 

scripting in SIMBAD

Earlier, I had built a spreadsheet with highly customised conditional formatting to show the B-V values with the cell filled with an appropriate colour. 


This will help as I compare all the colour impressions from the early adopters including Melody and Chris.

I've no doubt some of my colour descriptions are wrong...

Thursday, September 09, 2021

have you tried turning it off and on again?

Chris SMSed me. He was at the Carr Astronomical Observatory preparing for the University of Toronto Dunlap Institute "planet party." He started asking some questions about the network and related equipment so I put my tech support hat on.

He was not seeing the SSID for the network in the Geoff Brown Observatory. He asked if it needed a reboot. Nope. That unit died a while ago so no wifi inside the GBO. Hard line recommended.

He asked about the house wireless access points. They were only seeing the library and the furnace. What? I was surprised by that. The living room unit and the garage units (times 2) should be working. I asked for more information to get context. Like where he was located on the grounds.

In the kitchen. Then he shared that the house SSID was visible but not responding to the login. Authentication error or not connecting at all. Odd. I suggested he reboot the AirCube. 

He asked if the WAP was in the super's closet. Nope. Closer than you think.

A short time later, Chris relayed things were working. Good.