our first social

Ran the first virtual meeting-after-the-meeting. It was good. Decent turn-out. Fun to connect, albeit remotely, with friends and members. Some of which I haven't seen for a long time.

helped at speaker event

Helped at RASC Toronto Centre Speaker's Night. Alysa Obertas talked about how to destroy a planet. We need her on our side... 

Andrew asked me to be the questioner again.

The raw video is available for review on our YouTube channel.

received Winearls award for 2019

Wow. I won an award! I received the RASC Toronto Centre president's award, the Bert Winearls award, for my service to the centre. It is with great honour I accept it. No plaques this year, given the worldwide disease. Nevertheless, I'm thrilled.

I was completely surprised!

§

The 2019 citations were posted on the RASC TC web site.

found a tube

In the plumbing section of Home Depot I was thrilled to find a small copper coupling. It was in the bin labelled 1/4-inch but the coupler fits nicely over the shank of of a 3/8" bolt. Yes! A small pleasure. Aside from real Teflon, that might be the last bit needed for the Dobsonian base project. This will serve as a robust bearing, made of metal, in the azimuth pivot between the rocker box and ground plate. 

topics

Had a tele-meeting with my new editor. We discussed potential topics....

learned the link was fixed

I received a follow-up note from James E regarding link in my article in the October RASC Journal. He reported the link was "fixed in both [the high and low resolution] editions and uploaded to the website." Great.

quickly processed Mars

Captured Mars through the David Dunlap Observatory telescope with Andrew's video camera.

South is up, east is left.

74-inch telescope-Cassegrain mode, f/17.3, MallinCam Universe, MCU software 5.0, 200 milliseconds, AutoStakkert 3.1, GIMP.

The southern polar cap is at the top-left, reddened by the smoke in our atmosphere. Sinus Meridiani is the dark region right of centre while Aurorae Sinus is left of centre. Eden is the large light region at the 3 through 5 o'clock position. The prime meridian of Mars is nearly straight on...

posted Oct 2020 doubles

Prepared my double star "bulletin" for October 2020. It is a short list of suggested targets. I will share this on the RASC Toronto Centre forums. And I post here for everyone.

§ 

A few double stars for your observing campaigns.

Some of these double stars have dim elements, down to magnitude 10. So you might need a slightly larger rather than smaller instrument. But I think they are all worth it.

star	also known as	alternate catalogue(s)
ψ1 Aqr	STFB 12, 91	SAO 146598, HIP 114855
HJ 1940 Cep	Gaia 2739178880	TYC 04302-0707 1, GSC 04302-00707
10 Lac	S 813	SAO 72575, HIP 111841
PPM 172023 Peg	STT 443	SAO 126937, TYC 00555-0121 1
ο (omicron) Cyg	ο-1, 31 Cyg, HJ 1495	SAO 49337, HIP 99675

A quick note on omicron Cygni. Use every level of magnification you have, starting with Mark I eyeball. 

STFB refers to Struve Appendix B.

The Gaia catalogue number is from the second data release (DR2).

Enjoy.

Blake Nancarrow
astronomy at computer-ease dot com

received gas giants

Received a fun astro-themed card from Aubrey. The Papyrus card is sparkly, shiny, and iridescent.

Look at all those gas giant planets!

Does this mean I'm full of gas?

downloaded Oct journal

I downloaded the October 2020 Journal.

Ooh. Lots of comet images!

There's a piece on the various missions to Mars. That will be neat. There's an article about the biological impact of light pollution. Looking forward to that.

In my Binary Universe column I shared my experiences using the Loss Of the Night (LON) app. It helps you measure your local sky's brightness and transfers data to web sites (one by the LON team as well as Globe At Night) to be aggregated with reports. I tested version 2.1.7 on Android.

Unfortunately the supplied hyperlink in the article was broken, despite me spotting and reporting that during proofing.

§

Link fixed in updated PDF files.

tested at the DDO

With Ward's help, tested at the David Dunlap Observatory.

The main goal was to connect Andrew's MallinCam Universe to the 74-inch telescope to see if we could get decent images of Mars. And if all that worked, we needed to push the image out to Andrew via OBS. In doing this, we verified that we would be offer live views of Mars for the RASC TC YouTube live stream Mars Madness event.

It was a good opportunity for me to blow out the cobwebs. It's been a while...

spotted the Moon (Richmond Hill)

Spotted the gibbous Moon in the south on my way to the David Dunlap Observatory. Good, on one hand. Possibly we'd have clear skies...

received stick figures

Received a funny b-day card from the Horvatin clan. Only a little bit of Moon, thank the Universe.

Aw, shucks.

Doesn't really show in the photo but the stars are shiny on the Carlton Cards card.

I like the constellation stick figures. Especially the cake.

received tee and mug

Received a fun bday card and neat gifts from Rhonda. All astro-themed.

Kitty space cadet card by Avanti Press. Ha!

Interesting mug from the Wanakita camp, double walled. Inscribed "But I own the stars and the open sky...", it features a carabiner for a handle. Handy.

Cool shirt from the Life Is Good people.

I must move along.

EM spectrum

Hey, humans. Your skin detects infrared radiation. Not your eyes. Think about it.

continued collecting SNR data

With BGO, I continued to collect data on the West Veil, so to build up the supernova remnant mosaic. One of the hydrogen-alpha images however was damaged.

helped with RAN

Assisted the A/V team with the RASC Recreational Astronomy Night meeting. I was in charge of questions. Ran long but the talks were great. The rough cut is available for viewing on the RASC YouTube channel...

looking for BAL 1588

I found a "neglected" double star in the Washington Double Star database with only one observation from 1909. BAL 1588 in Aquarius. It is marked with "X" in the notes, the symbol for a "dubious double."

On checking SkyTools 3 Pro, I did not find a corresponding entry. But, using the location data (212509.61+015616.6), I identified GSC 00533-0360 at the same spot.

So I sent BGO Robotic Telescope on a mission.

Luminance filter, 2 second subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; left is east.

A good image despite sketchy conditions (some cloud, below average transparency, poor seeing).

GSC0053300360 is the medium-bright star up and left of centre. 

I do not see an obvious double near the centre of the image.

The WDS record says the position angle is 134 and the separation is 17.2. The star magnitudes are listed as 11.1 and 12.8.

ST3P reports GSC 00533-0360 as mag 11.8 (though poor quality).

The bright star to the right or west is HD 203873. To the right of that, nearly due west, in the dimmer star GSC 00533-0394, which is mag 12.8. That's way too far away...

The dim star to the south-east of GSC 00533-0360, a good distance away, is GSC 00533-0799. It's suspect datum for the magnitude is 13.3. It's nearly on the position angle. But again, not applicable by brightness and distance. 

So, this one remains a mystery...

It's fun that double star HD 203993 aka A 2289 is in the frame, to the north-east. ST3P says, in fact, it is a triple with AB separated by 0.2 seconds of arc. No. So we're seeing the C companion, around 225°. The planning app says they are magnitiudes 7.5 and 11.3 and 15.4" apart. Nice appearance. 

tried to spot stars (Bradford)

Brought the laundry in. A little late, I know. No stars... No planets. Smoke.

smoky out east

Spotted the tweet from the Burke-Gaffney Observatory, @smubgobs, Observations are disabled tonight due to SMOKE IN THE SKY from US Forest Fires!

printed the OTA

The printing in 3D of my model went very well! The optical tube assembly of the David Dunlap Observatory looks great! Ward did some maintenance work on his Ender, overcoming issues. The OTA on the right is the result. My redesign from 20 Aug, using subtraction, prints well. I've very happy.

That's the hard part (I think). Now we'll try printing all the other bits. The next key milestone is getting the articulation to work so that the OTA can be moved into different positions.

watched RAS news conference

Watched the RAS online news conference via the Astronomy Now web site.

Using Zoom, Philip Diamond, the director of the Royal Astronomical Society, introduced the speakers. They included Professor Jane Greaves, Dr William Bains, and Prof Sara Seager. Dr Anita Richards was also on hand from Atacama. They held a media news conference to share their findings on Venus.

A high amount of phosphine was detected in the atmosphere of Venus by radio astronomy measurements. The compound is produced on Earth primarily by living organisms and industrial processes. This signature may indicate the presence of microbes in the temperate layer of the atmosphere of the second planet in our solar system. See the paper at Nature Astronomy.

learned CSC goes 84 hours

Ah ha. Not my imagination! Not a glitch either. The Clear Sky Charts are wider.

I found this piece on the News page.

2020 September 11: More forecasts

CMC is now forecasting 84 hours into the future. Formerly it forecast only 48 hours into the future. From 3 to 48 hours, there is forecast data every hour (except for seeing). From 51 to 48 hours into the future, there is data every three hours.

There is currently no information as to how accurate the forecasts are for hours over 48. CMC belives their long range forecast is very good compared to other models. However, one should still assume the astronomy forecasts are most accurate for the first 12 hours.

[They are] migrating the clear sky charts to use the new data from 51 hours to 84 hours. It will take a few days. Expect not all charts to show the new data, and a few bugs until then.

Very good. It'll be nice to see a bit further out. Yes, the more we go into the future, the less reliable the data becomes. Still, I'm happy about this.

Having said that, it has mucked up a few of my weather resource pages, as the graphical elements are wider. And I imagine that will be happening to others too.

completed plate solving

With astrometry.net, I plate-solved all the Vulpecula double star images from the evening sessions on Thu 18 Jun and Fri 19 Jun. Consistent pixel scale numbers. But, as I suspected, the camera moved on Friday night, 2 degrees near the beginning, and 1 more degree half-way. Dang. I am still planning to analyse the drift images I took but I think I won't be able to use them.

prices doubled

Oh. I see. They had had SkySafari on sale for a couple of months. Back on the 5th, Plus was $9.49 and Pro $26.99. Now they were $20 and $53 respectively.

They just don't do this is a reasonable way, I think.

quickly proofed

Received a late request to proof my Journal column.

mostly clear (Bradford)

Some wispy clouds but fairly clear. Jupiter, Saturn, Summer Triangle, Arcturus. Visited some friends in town. They gave me some hockey pucks for my telescope project. We talked about comet 2020 F3 (NEOWISE). I answered some astronomy questions and, with my phone app, showed where Venus would be in the morning.

kp flat-lined

Don't recall ever seeing the kp-index so low and so flat. Nearly no activity. And here I thought we were coming out of the solar minimum.

From NASA NOAA Space Weather Prediction Center.

found NAN

While looking up the discoverer code for "SEI" double stars, I found an entry for "NAN." That means I'm in the WDS! Wow. That's crazy.

split T Cyg (Halifax)

On the evening of 13 Jun '20, from the backyard, with the C8, I tried to split T Cygni (BU 677). I did not successful see the allies of the triple. This seemed odd as they were not overly tight to the primary nor were they terribly dim. Used every ocular in the arsenal.

Sounds like a job for BGO!

Centring on TYC 02695-3170 1, I collected photons of T Cyg. And there they are...

Luminance filter, 1 second subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; left is east.

The B star is close in, at the 8 o'clock position, or south-east.

The C star, slightly dimmer, is at 5 o'clock. That's south-west.

Pretty easy... I wonder why I wasn't able to tag them with my rig? Was I tired? Bad seeing? Cloud? Too much contrast? Was I on the right star?!

Huh. There's another star! About the same separation as C, but on the diffraction spike to the west, so with a position angle of 270. It's really dim though.

Left of centre, to the east, there is the obvious, tight, faint pair, oriented nearly north-south. I had identified that before with the WDS as ES 249.

Once again, there are a ton of doubles and triples in the area...

caught up with Phil

Caught up with my buddy Phil. It's been a while. We chatted about various astronomy matters and had a good laugh of the salacious SkyNews. I miss camping together. Miss chillin' at the CAO.

corrected direction errors

Melody, while observing HR 8281, found some confusing notes in the double star supplemental table I had built. Indeed. Due to an error in my original observation. I corrected that mistake. I proof-read the entire table. And I added more helpful direction indicators, for the multi-star systems.

asked to contribute

Asked to write for SkyNews magazine. Wow! Yes! Absolutely.

received LON acknowledgement

Oh. Surprised by an email from Potsdam. An acknowledgement of my "recent observation" with the Loss of the Night app.

That was not exactly recent: August 11.

Must be a bit of a backlog.

Or the team output is impacted by a crazy global pandemic.

Regardless, they talked about the purpose of the email, encouraged the use of the mailing list for the most active updates, described how to see my measurements, recommended submitting often, and (again) reminded me to be safe while observing.

I was pleased, in the end. It's good to know something happened.

That said, I still do not see my measurements shown on the public map site...

looked for Moon and Mars (Bradford)

Grabbed my specs and headed to the backyard, avoiding the light sensor. Ooh. Clouds as I turned the corner, looking south. Right, I had seen rain forecast in the evening. Windy too. In the yard, on the shoofing grass, bunnies watching me no doubt, I did not see the Moon or Mars. Oop. There they are. Over the east hedge. Moved a best west. Wow. Clear patch of sky. The Moon is waning. Mars was bright. Seemed to have some dimension. Is that possible? Measured the separation of the two celestial bodies: one fist. Ten degrees.

returned to SEI 1371 (Halifax)

Asked BGO to image SEI 1371 (centred on SAO 70802). I first imaged this "neglected double" on 22 Sep '19. I did not receive a great image so I decided to redo.

Luminance filter, 2 seconds subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; left is east.

Looks a bit better... the image.

But there's no tight slightly dimmer B companion to the south-east...

tried for SEI 1197 (Halifax)

I suspected some space would be available in the queue with the... Moon. So I looked up some "old" double stars, previously known as "neglected doubles."

Found SEI 1197 from 1895 near GSC 03153-0148. A pair of mag 11 stars with a PA of 174 and sep of 14.7 with precise coordinate value of 203755.47+380520.1.

Luminance filter, 2 seconds subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; left is east.

With a position angle of 174, that would be nearly vertical in the image.

GSC 03153-0148, at the centre of the image, is mag 11.8, according to SkyTools.

The J2000 coordinates of the GSC star are 20h37m59.2s and +38°05'20". The Washington Double Star database coordinate would be very slightly right of the GSC star. Where there's nothing...

Those two equal horizontally oriented stars at 32 arc-seconds apart. So, looking for something about half that...

TYC 03153-0574 1 is intriguing. It's the medium bright star to the the south-east, 7 o'clock, with the fainter companion directly above. Magnitudes are wrong, position is wrong, but the separation looks right.

I do not see a pair of tight vertically arranged mag 11 stars anywhere...

I should pull up a proper motion chart...

§

Hold the phone! When I zoom into the image, I see a star below and left of GSC 03153-0148! Is that it?!

It's 15" away.

The position angle is 151°.

But it's MUCH dimmer.

SkyTools shows J203759.8+380506 at this location at magnitide 16.3.

Which corresponds to other mag 16 stars in the area...

Is that it?

Begs the question, how low does SEI go?

Could it be that Scheiner, J. saw the mag 16 star but accidentally marked it with the mag value of the primary?

§

OK. Ran a query on the 18-24 segment of the WDS and searched for the "max" mag on the secondary: 15.3! So he does go pretty low.

imaged 19 Cyg (Halifax)

Here we go. First of a few double star images courtesy the Burke-Gaffney Observatory.

Centred on TYC 3137-0475-1. I wanted to visit 19 Cygni (aka HJ 603), to get C and E stars. I attempted this target in my Ontario backyard on 16 Jun '20 with my C8 and picked off the B and D sparklers.

19 Cyg A is the obvious bright star.

Luminance filter, 2 seconds subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; left is east.

Well, C and E are certainly visible, according to SkyTools 3 Professional. But it begs the question: how would one distinguish these from the many field stars?!

B is the brightest nearby star at the 8 o'clock position, a modest distance from the primary. If I had to guess the position angle, maybe 110 to 115°? Easily spotted in the small rendition of the image, zoomed out. ST3P says: PA 112°, separation 56.0", magnitudes 5.2 and 10.4.

The C (natch, see below) companion is north of B, almost perfectly due north. Much fainter. Barely visible zoomed out. Almost on the east diffraction spike. The AB pair PA and sep guesses: 91° and 51". ST3P says the pair information as BC: PA 13°, sep 21.0", mag 10.4 and 11.1. Gonna have to do my SAS triangle calculations for the AB numbers. I think it is much dimmer than 11. It seems closer to mag 13 or 14.

Attendant D is well away, opposite B. It is slightly dimmer than B at 3 to 4 times the distances. ST3P: 312°, 168.6", 5.2, 11.8. Indeed, if D is close to mag 12, C is below that...

The E (blurg, see below) star is the dimmest of all. I have to squint to see it in the zoomed out image. It's obvious zoomed in, between A and D, almost perfectly in-line, but is dimmer than C. The planning software says this about AE: 322°, 102.8", 5.2, 12.6.

Some of those numbers in SkyTools are wonky.

From Stella Doppie. All data no older than 2014.

AB: 115, 56.8, 5.38, 10.54

AC: 318, 96.6, 5.38, 12.60

AD: 309, 163.8, 5.38, 11.90

BC: 309, 150.5, 10.54, 12.60 (a curious cross-check)

BE: 11, 20.8, 10.54, 13.50

Oh, oh. The labels are different. SD says B and E are to the south-east and C and D are NW. That's a flip of C and E...

Weird. They say E is the dimmest. Nope.

The E star (new) is nearly 90°. I had guessed 91. My SAS calculation says 93° with a derived separation of 55.6".

So this was a good imaging task. It plucked out the C and E stars, revealing they are very faint. Near the magnitude limit of the 8" Schmidt. I don't recall the conditions but they'd need to be pretty good to get these comrades. But, again, it might prove challenging, without the aid of good software, to know the associates from surrounding field stars.

The "undesignated" pair I noted 3 months ago is obvious, to the north-east, oriented north-south, same separation as BE. In fact, the same position angle as BE.

One could easily argue there are many double stars here.

imaged HD 202073 (Halifax)

Ordered the BGO bot to image double star HD 202073 aka BU 270 / S 781. In the backyard in with the C8 on 16 Jun '20 I had tried to spot the companions. Saw D but not C. In the image, A is dead centre with D below, south, equally bright.

Luminance stacked image was corrupted. This is the red filtered stack. 6 seconds, 12 exposures. FITS Liberator, GIMP. North is up; left is east.

C is obvious, zoomed in, barely visible zoomed out. It is at the 11 o'clock position to A, quite close. Very dim. SkyTools says it is magnitude 12.7. I think it looks as bright as mag 13 and 14 stars in the field... [ed: Stella Doppie says the C element is 14.1! Explains why I didn't see it...]

There's a B star in the mix, a fast-period binary, in this Equuleus multi-star system. But at 0.5", it is too close to A to split.

Lots of faint doubles in the 'hood...

caught some of the West Veil (Halifax)

Wasn't expecting that!

While the skies were clear on the east coast and I was anticipating double star image requests to be completed, the BGO Robotic Telescope sent a message about TYC 2687-0782-1. It was actually the ID job number, 11874, that caught my eye. It was from my Veil project. Ah. The Moon had not yet risen enough to exceed my "maxmoon" constraint. All right then!

Part of the West Veil aka NGC 6960. Southern portion.

Hydrogen-alpha, 60 seconds subexposures, 10 stacked shots. FITS Liberator, GIMP. North is up; left is east.

Oh my. Look at those tendrils drifting down. Looks like I need to add another row to the image mosaic...

saw Saturn and Jupiter (Bradford)

I chose mint ice cream. 

Someone took our bench! We had to sit at the rock in the parking lot! Gosh! So I couldn't see Jupiter and Saturn unless I stood up. Geez!

Checked SkySafari. Mars wasn't up yet...

solar flower power (Cookstown)

Visited Laura's Farm Stand north of Cookstown. The maze sunflowers were past their prime (but not ready for harvesting). Deeper in there were some extraordinarily tall plants.

Witness, solar energy at work.  

Canon 40D, 18-55, ISO 1000, f/14, 1/160 second. Digital Photo Pro, white balance, crop, saturation.

Now I really wanna grow some next year...

more Dob progress

Got off my lazy butt and did some more work on the Dobsonian base for the Edmund Scientific.

In fact, the first thing I did was a quick test fit and eyeballing of the cradle against the 6-inch reflector (with the 7½" optical tube assembly). As I expected, I'll have to cut down the inner braces a bit, chamfer them a little. Whew! I did not goof up on my dimensions for the cradle.

Did some test fitting of the laminate to the altitude bearing on the cradle. Gonna be good!

Put the found scrap pieces of 1x4 in the rocker box at the foot of the front plate. Cut down the last good piece of 1x4 for the foot of the rocket box, back, the open end. Corrected a small mistake. Can't tell from an airplane.

Finally, after making a template, I affixed the circular base plate to the rocker box. All but done the rocker.

viewed Mars and Moon (Bradford)

Popped out to the deck for a moment. "What's that? Wait? What?" Rhonda asked. It looked better than I was expecting, bright orange Mars one lunar diameter away from the gibbous Moon. A spectacular view!

learned labels work

Oh! They do work! Tags or labels in the blogger back-end seem fine! Even though the interface no longer shows the check list and (initially) says "No matching suggestions," the tags still work! 

If you type into the text box above, they appear. Whew. Still there, still work, don't have to recreate them.

It's still flawed because you don't see them listed which is disconcerting. And you don't know how they're spelled so you have to go from memory.

Once you enter one, the prompt or message changes to "Include more letters to see label suggestions."

Pfft.

reading paper on triple with planet

I've been reading about the triple star system in Orion with a possible planet!

I first learned about this in Neatorama, of all places. An astronomy piece by Miss Cellania.

They referred to an article at the LiveScience web site. The article there is entitled Rarest planet in the universe may be lurking in Orion's nose by Brandon Specktor.

That article has links to a paper at Science (published Sep 3) and at the Astrophysical Journal Letters (from May 21). The first appears to be behind a pay wall but the second offers the full paper.

The paper is entitled GW Ori: Interactions between a Triple-star System and Its Circumtriple Disk in Action lead by Jiaqing Bi. From the abstract, the authors state "GW Ori is a hierarchical triple system with a rare circumtriple disk."

There appear to be three dust rings surrounding an AB-C binary where each disc is at different inclination angle from the others due to a tearing effect. This could be explained by a planet in the system.

If all this proves true, it'll be pretty neat. And again shows that there is infinite variety out there. 

This stuff has been the domain of science fiction...

§

Spotted a post at AstronomyNow on the subject.

§

I just had a thought. Are we seeing the normal formation of a proto-solar system wherein comets are allowed?

§

Performer Eric Brenn on the Ed Sullivan show via the CBS Photo Archive.

tag weirdness

Things were going pretty good with the blogger back-end.

But a few days ago they did something to the labels. Now when I add or edit an article, the labels section says "No matching suggestions." Are these tags lost? Will I have to recreate them?

It's not obvious how to add tags to new posts. Old posts appear to hold their tags but I dare not edit them. 

The label cloud, from the front end, seems fine. So for the viewer all seems well.

let's settle this

OK. I think I've had enough of this...

Recently, I've heard a few people say that large aperture telescopes cannot render good views because they are susceptible to bad seeing conditions. A larger aperture means the tunnel of air you're looking through is bigger.

I am not convinced. A bigger 'scope means better resolution. I'll take resolution thank you. And greater light gathering capability.

Any telescope on the ground will be affected by seeing conditions. So be it.

That's what's so great about Environment Canada's weather tools: it predicts seeing quality.

Yes, the biggest telescopes on the planet use lasers and adaptive optical systems to correct for the air.

Anyway, I'm going to research this... I'm going to see if I can find empirical studies on this. I think most people are speaking from anecdotal experience.

Stumbled across an interesting statement by "TOMDEY" in Cloudy Nights.

What [people don't] take into account are the ~moments~ of good, great, excellent seeing.  So, if you dwell on a target long enough, patiently enough, with a giant scope at higher mag...  you will see far more than the little ones can ever see.

Bingo. That's good.

And that speaks to the entire visual system, the telescope, eye, and brain (arguably the most important part).

§

Now, let's find scientific papers on the subject... If you know of any, share in a comment.

assembled NGC 1023 in colour

Processed NGC 1023 using the LRGB data from 28 Aug '16.

FITS Liberator, Photoshop. Normal colour processing techniques plus star minimisation. 

§

Discovered in this assembly that the colour channel files are... damaged. There are noticeable streaks.

Campbell to lead CSA

Caught the headline out of the corner of my eye on CP24. Awesome news. Lisa Campbell has been named to replace Sylvain Laporte as president of the Canadian Space Agency.

learned about the Rubin observatory

Watched a short video on the Vera Rubin Observatory currently under construction in Chile. Learned it has an 8.4-metre primary mirror and will use a 3.2-gigapixel imaging camera. 

Oh. The camera's diameter is almost as big as the primary at the DDO! Wow! Lots more info at the amazing wikipedia, of course.

Diagram by LSST Project/J. Andrew.

finding low temp stars

Read in detail an article at SciTechDaily. It's entitled Nearly 100 Cool New Worlds Found in Our Cosmic Backyard With Key Help From Citizen Scientists.

It describes how Backyard Worlds volunteers, using survey and archival data, discovered roughly 100 low-temperature brown dwarfs near the Sun, with one as close as 23 light-years. 

You too can contribute, to this project, or others at Zooniverse.

those colours

Wait! Are the colours of sunset like those in black body radiation?!

§

Huh. Found this article at io9 entitled why the sky doesn't turn green at sunset. Interesting...

he tried to print the OTA

Heard from Ward while he convalesces. He attempted a 3D print run of my DDO model, specifically the redesigned optical tube assembly.

I think it looks pretty good except for a small problem [caused] by a partial clog in my print-head that lead to a bunch of stringing.  The rings are pretty solid and looks well defined and there doesn't seem to be any issues with anything else.  Good job on the design–I like it!

He's gonna clean out the hot end and give her another go later on.

looking for spikes

Had another go but used the Apogee sensor this time... The Burke-Gaffney Observatory robotic telescope complied.

The IK Pegasi image from a couple of days ago showed double diffraction spikes around the bright star. What? A double star? No... I suspected it was a fault due to bad calibration.

Luminance only, 2 seconds subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; east is left. Again, I aimed at TYC1671008041.

Captures, in reverse chrono order:

• 29 Oct 2022
• 8 Sep 2021
• 1 Sep 2020
• 28 Aug 2020
• 12 Sep 2019

No dual diffraction spikes... So the 28 Aug is a bad image. Or it's a stunningly fast binary.