Thursday, January 31, 2019

received stepper motor suggestion

photon_trap commented on my barn door tracker YouTube video.
Great presentation, thanks.  My BD tracker is also a Gary S. in terms of dimension but I switched to a stepper motor which made a huge difference, insuring proper speed regardless of load.
I thanked him for the tip.

Sunday, January 27, 2019

considered physical layout

Needed to do some board layout work with the physical components of the new dew heater controller. Sort placement and spacing issues now that I had a working prototype.

Used ExpressPCB once again. Copied the Sayal 103 perforated board layout from a previous project. Adjusted for wanting a number of diodes and resistors in a vertical orientation. Happily I found the old TO-18 transistor package in the component manager. Tried to space things out away from the power transistors and their heat-sinks all while keeping the layout as compact as possible. It was clear I would need a lot of jumpers. This was feeling more complex than the barn door tracker build...

Something new this time: I printed the board layout I created to paper. I was pleasantly surprised to find it was scaled perfectly. I laid it atop the perf board and used a push-pin for the through-the-hole lead positions. It worked really well.

I stared at the schematic for a long while. I rigorously checked all the nets. Everything seemed OK. I was certain I had not wired it up wrong. The next stage was important!

[ed: I am not including the image of the PCB from the software is it had errors at this stage.]

On the generous project box, I considered where to place the knobs, switch, RCA plugs, LEDs. Oh, and the fuse. The found fuse holder was big... But it looked like there'd be room.

I examined photos of do-it-yourself projects and commercial units in the interest of mimicry. How did other people arrange things? I was drawn to symmetrical styles.

Then, for the first time ever, I dove into old 123D to look for physical collisions. Cool! This was rather profound in helping me ensure that the circuit board elements would fit while not interfering with the case components. The TIP31C transistors with their heat sinks literally needed some breathing room, the business-end of the 1 mega-ohm variable resistors were big, and the fuse holder was rather long. I made a rectangular prism to represent the PCB volume. Turning the case transparent in the three-dimensional software let me see what might happen.


Later, when I removed the fuse holder from the project box, knowing that I could rely on the fuse in the CLA connector, I reworked the case.

planned box layout for the custom dew heater controller

Lots of room inside. And I could easily create a balanced look. And I think it's a smart layout with outputs on the left and right sides. If placed horizontally at the telescope, some heating elements will be at the front of the 'scope and some at the back.


Next: soldered stuff.


Put exported data file out there so you can view it in 3D!

Saturday, January 26, 2019

bittersweet discovery

Started more testing with my dew heating gear. I needed to know that the new circuit design was correct and could drive a dew strap band. It was strange that I wasn't feeling any heat off the Kendrick 2" dew strap. Tried a direct connection of a heater to battery. Nothing. What?

Tried the custom circuit again. Noticed the CLA LED was not lit. Opened up the Cigarette Lighter Adapter to find a blown fuse! OK. How did that happen? I have a million spares. I loaded in a 5A fast-acting. OK, power was good now. But no heat. Please, no...

Checked the resistance of the 2" heater. It was open. Damn it! Now I have a malfunctioning or dead dew strap. Did I somehow overload a circuit and blow up the 2" eyepiece heater?!

Tested the Kendrick 8" strap - OK! Whew. On the prototype, I found the power transistor, as expected, getting toasty warm. This was good news. Overall, the circuit was correct.

But I was dismayed. Setbacks, frustration, sadness. And there's a distinct possibility there's something wrong with 2" heater.


Now I'm wondering... when did this happen? Was it a past issue? Back on 5 Jan '19 in the backyard the 2" heater did not seem to be working.

I dunno. Blown CLA fuse, blown multi-meter fuse... Sure looks like I did something wrong in the last day or two. Gah.


Realised the old Micronta digital multi-meter wasn't working right. Opened it up and found a blown fuse! Whiskey tango foxtrot! Fortunately, there was a spare unit tucked away inside the battery compartment.


There's maybe a lesson to be learned here: do not do early prototype testing with expensive dew straps...

a partial prototype

With the new parts from amazing digi-key and my coddled bits, I prototyped the dew heater controller circuit with the IC 556. Or one half of it anyway. That is, I set up one potentiometer for one of the channels. It seemed to be working with the LED flashing at different rates. The pot changed the duty cycle. Good, in general, all the parts were working! I saw volts on the heater net, flicking on and off with the duty cycle. Curiously, I did not observe amps registering. Weird. I stepped away.


Next: considered physical layout.

Friday, January 25, 2019

gathered the parts

Checked my electronic parts inventory for the dew heater controller build. I was surprised by all the parts that I already had.

From my personal supplies: a single-pole single-throw switch, 2.2 kilo-ohm resistors (4), 1N4148 signal diodes (4), diffuse red 5mm LEDs (2), male CLA plug with in-line fuse, various fuses of different ratings and speeds, and a suitable perf board. Oh, and I had small 4-40 bolts and nuts.

From the supplies provided me by my friend Dietmar Kupke I was thrilled to find: a LM556 dual timer IC, 47KΩ resistors (2), 10 nano-farad capacitors (2), and 1μF electrolytics (2). I was pleased to find a good sized black plastic project box.

I was blown away to find 2N2222 transistors (2), in the TO-18 package no less, as called for in the schematic diagram. Seen these old things but never used 'em before.

I had lots of wire: fine 22 or 24 gauge solid for signals and heavier stranded for high-amperage pathways.

Didn't know if I would need or use them but I also collected up some grommets, a fuse holder, various wire terminal blocks, and 16-pin IC socket.

From digi-key, I found: variable 1MΩ pots (2), knobs for the pots, a Schottky diode, TIP31C NPN power transistors (2) in the TO-220 package, small heat sinks for said TIPs, and RCA female connectors (4).

As expected, way less money than buying a commercial unit. In fact, 1/5th the price!


Added to the order parts to replace missing pieces from the electronic lab. Also found battery packs for some other astro-projects...


Next: a partial prototype.

Thursday, January 24, 2019

batteries outside

Made a simple external battery pack for the ETX. From spare parts. Plugs into my previously-added dongle which means I don't have to take the heavy base plate off each time! Stoopid design. And—fringe benefit—I should be able to avoid blowing up batteries inside the unit!

Wednesday, January 23, 2019

watch Luna go to the Moon

Stumbled across the One Small Step short at Neatorama. It's about a little girl who dreams of being an astronaut and a very supportive shoemaker dad. Warning: get out your box of tissues.

I love the animation. I love the music. Of course, it's a wonderful story.

[ed: Noticed on 8 Feb 2019 that the video link didn't work. When I go to Vimeo, it is described as private.]


18 Feb '19: Found the trailer on Vimeo.


Update 19 May '19.

Found it again, the full piece, on YouTube.

Tuesday, January 22, 2019

surprised by emails

I was surprised to find emails from the Burke-Gaffney Observatory in my mailbox. I did not know the robotic 'scope was operating. I had not received Clear Sky Alarm Clock email alerts. But I also didn't have Rainmeter running with my little Clear Sky Chart indicators. So I was caught off guard. Of course, the recent clear weather in Ontario had reached the east coast...

imaged POU 1931 (Halifax)

The BGO robot imaged POU 1931 for me. Another neglected double-star, this time in Gemini.

Actually I aimed at GSC 01893 00812 and then used the OFFSET option nudging in RA -10 (west 10%) and Dec -5 (south 5%). This is where the double should be. There's nothing there. The SkyTools chart is similarly void.

It is curious though the tight equal pair of stars east of the equilateral triangle.

neglected double-star POU 1931 in luminance

Luminance only, 2 seconds subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

The WDS entry is:

06428+2320POU1931      1901 1901    1  38  38   6.0   6.0 10.8  10.8                                            064245.  +231954.

This shows the data is over 100 years old. The PA is 38 and sep 6. Both stars are magnitude 10.8.

That bright pair is at the location in ST3P noted as 6 42 25.7 and +23 19 59. The software calls this Tycho 01893-1748 1. This looks suspiciously like an error in the initially recorded RA data.

That said, ST3P says it is magnitude 12.3. But the stars in the pair look to be the same brightness as the southern stars in the triangle, which the software says are mags 10.6 and 11.5.

I calculate the following:

separation calculated 7.0 arcsec
position angle calculated 41 degrees



POU 1915 is a faint tight pair to the far north-west.

POU 1944 is the obvious wide pair of faint stars to the north-east.

There's a vertical streak in the centre of the image. Looks like a cosmic ray.

imaged STF 594 (Halifax)

BGO captured Σ594, a neglected double-star in the constellation Perseus. Also known as HD 276956 and SAO 57445. Near the centre of the image. In a neat inverted T-pattern of stars.

neglected double-star STF 594 in luminance

Luminance only, 2 seconds subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

SkyTools shows this as a double with a PA of 333° and a separation of 9.1 seconds of arc. Magnitudes 9.0 and 10.7. I.e. a slightly dimmer close companion to the north-west. I dunno about you but I don't see anything at this location...

Curiously, I see a double to the north-west, in the same orientation as what ST3P says should at target location... ST3P calls this star HD 276957.

Also, I see a faint companion to the north-west of that! ST3P refers to this star at TYC 02893-0092 1.

I pulled the entry from the WDS:

04495+3914STF 594      1832 2018   22 311 332   8.0   8.8 10.23 12.0  F0        +002-010 -006+001               044919.40+391554.6

Huh. There's 2018 data. PA 332 and sep 8.8. With mags 10.2 and 12.0. Huh.

But on examining the "Precise Coordinate" data, it gets interesting. The location of Struve 594 is noted as RA 04 49 19.4 and Dec +39 15 54.6.

And that's the location of obvious double that ST3P calls HD 276957. Mystery solved. The original entry recorded in 1832 by Struve was in error.

Stella Doppie shows a number of entries since 1998. The PA ranges between 331 and 332. The Sep. was noted as 9.1 or 9.2 until 2018 where 8.8 appears. There's a jump in the mags too.

I plate solved my image.

Size: 23.9 x 23.9 arcmin
Pixel scale: 3.59 arcsec/pixel
Orientation: Up is 0.026 degrees E of N

Using Visio, I made a scaled ruler and measured the PA and Sep:

separation calculated 9.9 arcsec
position angle calculated 329.4 degrees

Wow. I'm off by quite a bit. Still, my image clearly shows that the target star is not the double in question.

imaged FOX 134 (Halifax)

BGO imaged FOX 134, a neglected double-star in Perseus, a bit east of ν (nu) (off frame). This image is centred on Tycho 28710 1584 1. The target is the obvious tight double in the large triangular grouping of stars down and right of centre.

neglected double-star FOX 134 in luminance

Luminance only, 2 seconds subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

SkyTools 3 Professional did not include a reference to FOX 134. It does show a single star at that location: GSC 02871-1837.

I plated solved the image with It returned:

Pixel scale: 3.59 arcsec/pixel
Orientation: Up is 0.00274 degrees E of N

I pulled the line item from the Washington Double Star catalogue:

03467+4241FOX 134      1923 2017   10 104 108   6.1   5.9 10.0  10.4            -040+004 +029-006               034645.01+423927.4

The 2017 entry shows:

position angle 108
separation 5.9

With magnitudes of 10.0 and 10.4.

Stella Doppie shows 3 sets of entries:

2007 5 108 5.8
2010 8 106 6.2
2017 9 108 5.9

With matching magnitudes.

Using Visio, I made a scaled ruler and measured the PA and Sep:

separation calculated 6.6 arcsec
position angle calculated 106.9 degrees

That's interesting. My numbers are similar to the SD data from 2010.


Curiously, Tycho 28710 1584 1 looks like a double!

Monday, January 21, 2019

watched the eclipse (Bradford)

10:47 PM. Checked the Moon. There was a bite out of it. Bright stars. Bitterly cold air. Too extreme for a camp fire. I was too lazy to program the camera. It was -30 to -35°C with the wind chill...

Windows desktop during eclipse

I simulated it in Stellarium and watched it online...

The TimeAndDate web site was wonky when I tried to access it directly. Later though I found the interactive graphic. It was good.

11:36. Rhonda said it looked like an eyeball with a contact lens.

11:47. Totality! Dark on the ground, very little reflected light now. Just a light glow on the top edge of the Moon.

The internet trolls in the chat feeds were super-annoying!

12:15 AM. One last check. Whoa. Dim. Not red. A dull orange colour. I said, "Orange lollipop." "Creamsicle," Rhonda said.

eclipsed Moon from California

The imagery from the Griffith Observatory was quite good. Bang on with the colour.

Sunday, January 20, 2019

next council meeting posted

I learned that the next RASC Toronto Centre council meeting will be on Tuesday Jan 22 in room 258 of the Petrie Science and Engineering building at York University. Members are welcome to attend.

Saturday, January 19, 2019

first monthly double stars for 2019

Issued my double star "bulletin" for January 2019. It is a short list of suggested double and multi-star targets. I shared this on the RASC Toronto Centre forums. And I post here for all.


Happy new orbit! While deep in the grey season, I enjoyed a decent clear night recently and knocked down a few more double stars. You could too.

staralso known asalternate catalogue 
ρ (rho) OriΣ 654SAO 112528
φ (phi) TauSHJ 40SAO 76558
15 Mon *STF 950HIP 31978
HD 49024 CMaHJ 2341**
12 CetHJ 322SAO 128791

* Have fun with 15 Mon!

** I can’t find a SAO number for HD 49024 in Canis Major but it’s near SAO 172296 if that helps… :-)

Please consider adding double stars to your observing list. They are fun, easy, sometimes challenging, interesting, colourful, and dynamic! I look forward to hearing how you did! Any questions?

Blake Nancarrow
astronomy at computer-ease dot com

Friday, January 18, 2019

imaged neglected MLB 811 (Halifax)

Commanded BGO during a lull to image neglected double star MLB 811 in the Andromeda constellation aiming at nearby SAO 54361.

neglected double-star MLB 811 in luminance

Luminance only, 2 seconds subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

The poor sky conditions degraded the image slightly.

SAO 54361 is the bright star near centre. The target pair is due east. Very faint!

The WDS shows:

01024+3958MLB 811      1933 1933    1 196 196   5.9   5.9 10.1  10.0                                         D  010225.51+395833.8

No observations since 1933. Unchanged PA and Sep at 196° and 5.9" respectively. Mag 10 stars.

Stella Doppie lists observations in 2007 and 2015. Both note a PA of 202°. The separation is 7.2 or 7.3. Interestingly the 2015 report states the magnitudes are 11.8 and 13.0 for the A and B stars. In my image, think they are nearly equal.

My quick measurement of the image yields of position angle of 201 degrees.

Thursday, January 17, 2019

imaged neglected ES 619 (Halifax)

I asked BGO (with the Windows app) to image neglected double star ES 619 in the Andromeda constellation. It didn't like the HD 14471 reference so I aimed to GSC 03294 01815. Given the empty queue, it captured the target within minutes. ES 619 is the brightest object, just right of centre.

neglected double-star ES 619 in luminance

Luminance only, 1 seconds subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

The Washington Double Star database notes the following:

02215+4625ES  619      1894 1970    3 240 246   5.1   5.9  7.9  10.6  K5        -028+009          +45  600   D  022129.8 +462455.

So no observations since 1970. Position angle then was 246 degrees with a separation of 5.9 arc-seconds. The primary magnitude is listed at 7.9 while the secondary is 10.6.

Stella Doppie lists observations in 2008, 2014, and 2015. The latest suggests the PA is 245° and SEP is 5.7".

Mine is not a great image. There are problems in the stack. Probably the sky conditions were a factor. I'm inclined to redo it but in the meantime a deep dive does show a dim companion to the west.

Monday, January 14, 2019

had a thought

The thought occurred to me on the train-ride up to Ottawa that during bright Moon phases I could try to shoot some neglected double stars with the Burke-Gaffney Observatory. Accessed a list for candidates with separations greater than 3 seconds of arc visible in the northern hemisphere. Hundreds to choose from. Good.

spotted dogs (Aurora)

As I travelled to the city to catch my VIA train, I took in the sky and its wispy clouds. Initially I didn't see anything... But later, from the Aurora GO station, I spotted colours.

There were tiny sun dogs. The right one was brighter. They slowly wavered and slowly dimmed. I stood in the shadow of a lamp post for a better view. No rings or arcs anywhere.

Later looked for and found Moon, I guessed about 15 degrees up. Waxing, around first quarter.

collected photons from M98 (Halifax)

The BGO aimed at Messier 98 for me. A large spiral galaxy in Coma Berenices. Viewed only once before (on 19 May 2012).

galaxy Messier 98 in luminance

Luminance only, 60 seconds subexposures, 10 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

The wonderful nearly edge-on galaxy also known as NGC 4192 looks distorted, particular to the north. Something interfered with it in the past, bending and flexing it. It almost looks like two discs parallels. I can see multiple arms and concentrations of stars within. There seems to be an inner region that is much brighter. Compact and intense core.

Quasar Q 1210+1507 is easy to see. It is to the west of the spiral, in an equilateral triangle with stars J121314.4+145000 and J121307.6+144902.

To the south-west of the galaxy, well away, is a round dim patch: MCG 3-31-76.

Just to the north of this is a tiny dim oval: LEDA 1467279.

NGC 4186 appears to the south-south-east, a nearly face-on spiral, small, with a large bright core.

I can see still more galaxies in this image... Busy place!


Wikipedia link: Messier 98.

captured M87 (Halifax)

I captured Messier 87 with the BGO robot. Another galaxy in Virgo. Another M target viewed only once before (again on 4 May '13).

galaxy Messier 87 in luminance

Luminance only, 60 seconds subexposures, 10 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

The coolest thing? You can see the jet emanating from the core! The relativistic jet from the intense core of Messier 87 is angled to the west-north-west. Wow.

M87 is a rather large elliptical galaxy again oriented south-east to north-west. Smooth and uniform. M87 is also known as NGC 4486 and Arp 152.

To the north-west, there is a very compact, small, round galaxy, almost star-like. It is NGC 4486B.

I didn't see it at first but there's a tiny sliver below the pair of stars with J123022.1+122822. This distant galaxy is LEDA 139910.

Bright NGC 4478 is to the west-south-west. It has a bright core with a diffuse cloud surrounding it. Is it an elliptical as well? There's also a bright point just above, to the north, very close. Another galaxy? Or a star?

To the south-west, very near the core of grand island universe are two nearly equal faint oval fuzzies. SkyTools shows the same designation for both: UGC 7652.

To the south-south-west is an oval fuzzy with intense bright core: NGC 4486A.

IC 3443 lies to the south-east, a soft, faint medium bright object, with a brightening in the middle.


Wikipedia link: Messier 87.

imaged M49 (Halifax)

The Burke-Gaffney Observatory imaged M49, a big galaxy in the constellation Virgo. One of the Messier objects I had logged but once (back in early May 2013). I wanted to return for another look.

galaxy Messier 49 in luminance

Luminance only, 60 seconds subexposures, 10 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

Messier 49 aka NGC 4472 and Arp 134 is a smooth uniform elliptical. Blinding bright core. What would it be like on a world there with such a bright galactic core?! Surely the night sky would be very bright... The large galaxy is oriented south-east to north-west.

The outer limits of the canted galaxy extend further out than what I can show in this image. I still struggle with Liberator and drawing out faint details.

There are many little neighbouring and distant background galaxies in this simple image.

I missed it given the star-like appearance but SkyTools 3 Professional noted NGC 4464 to the north-west, near the top-right corner of the digital image. On closer examination, it is a compact almond-shape with a bright core, oriented north-south.

Between is the perfectly round fuzz ball of PCG 41180.

To the west-north-west there appears to be a double galaxy, two faint tight objects, with a dimmer one to the north. ST3P only marks the lower object: NGC 4465.

Due west of the big galaxy, is the medium-bright round galaxy of NGC 4467. It is just east of a star making for a good comparison of faint fuzzy and blotted star.

South-west, about the same distance from the core as 4467, but fainter, is PCG 41185.

Further out is the very faint LEDA 1333286.

And still further out is a large spiral, just at the edge of the frame, at the bottom-right. That's MCG 1-32-76.

Curious NGC 4470 is nearly south, an amorphous mottled blob. It looks like a spiral that's been smashed (previously seen).

The big, round, uniform, but extremely faint MCG 1-32-84 shows to the south-east of M49.

And lastly, to the north-east, I see a somewhat large round fuzzy with a bright core: PCG 41264.


Wikipedia link: Messier 49.

clear in ON and NS

Clear everywhere. Ontario and Nova Scotia. But it was awfully cold here. Didn't feel like braving the elements. And I had some home work to do. Looked like I'd get some images from BGO but nothing had happened when I turned in.

Saturday, January 12, 2019

designed dual control schematic

When I realised I needed another dew heater controller (operating under the assumption that the cheapo LED dimmers were not up to the task) I started looking at do-it-yourself solutions.

Found one that I liked using a 556 dual timer integrated circuit (IC) chip. It featured four outputs but offered two independent controls. And the LEDs on the output side would pulse to hint at status or the duty cycle. Those things would take it a couple of notches up from my existing old classic Kendrick Type IV. Oh, and this design could be built with component electronic pieces, many of which I knew I already had. (I'm still not ready to jump into the Arduino pool.)

The author shared his specifications including the input voltage range, 8-18 volts direct-current (recommended 12VDC), and the maximum current for each pair of channels at 3 amperes (1-2A recommended). Good stuff.

custom schematic for dual control dew heater box

Based on the design by Michael Vlasov over at, I built a circuit in ExpressSCH.

[ed: For clarity, so to avoid confusion, this is the final corrected schematic.]

N.B. Express uses a modern style without hops or bumps when wires cross. So, read carefully. If there's not a little square or round bullet, there's no connection.

I ditched the 6 volt output element (as Michael suggested).

I added a fuse to the circuit schematic. He recommended it; I was planning to do so anyway. By the way, the offset of the battery and fuse are meant to show that the power source and fuse are external. The circuit could be powered with a marine battery, booster pack, or power tank attached with a Cigarette Lighter Adapter (CLA). I plan to use a CLA plug with built-in fuse. In other words, the fuse is not in the project box or on the circuit board.

I added reverse-polarity protection with the Schottky diode. Just in case I hook something up wrong one day in the future. (Which will be on the circuit board.)

Aside from those changes, I kept everything the same...

That said, the C4 and C4 electrolytic capacitor values can very. I found a circuit based on a 555 IC that called for 1.5 micro-farad caps. I later tested with 1.0μF and 2.2. It just changes the shape of the duty cycle.

Speaking of the 555 circuit, it showed 10 kilo-ohm resistors on the output of the chip. I tested R5 and R6 with 10KΩ and 2.2K and both worked fine.

The R7 and R8 resistors might be important to change. It will be affected by the current threshold required for the light-emitting diodes (LED) D5 and D6. You might deliberately want to throttle the LEDs so to not be too bright late at night. To that end, you might make a point of using low intensity diodes with diffuse packages.

I considered multi-turn potentiometers for the 1MΩ R1 and R2 components.

Michael's part list showed Q1 and Q2 as 2N2222 transistors. That's a old, obsolete type so you may have to make substitutions with another NPN.

Also TIP31 power transistors are discontinued but you should be able to find equivalents.

I briefly considered changing from the TIP31 type for more power but in the end stayed with it. Also MOSFETs are worth looking at.

I encountered some challenges with the transistor elements in the circuit design tool. When I used the NPN transistor element, I had to assign the pins. Initially, I made an assumption that it didn't matter what the numbers were... Learned a lesson there (which I'll document in another post). To the point here and now: be careful that your pin-outs match your physical component. With transistors, of course, the base, collector, and emitter pins can be anywhere! You'll note by schematic shows different pin layouts for the different purposes.

I also started a board layout file, using ExpressPCB. I knew this would need to be revised once I had all the physical parts, considering form factors, spacing issues, and whether I would arrange parts horizontally or vertically on the perforated board [ed: which generated a significant error that would haunt me].

One final note: your circuit can be tested without heaters attached...


Next: gathered the parts.

Friday, January 11, 2019

checked controller prices

Window shopping... Dew removal controllers. All these units provide power output to dew heater straps or wraps using the pulse-width modulation (PWM) technique.

model outputs notes price
Kendrick Micro-D 1 Also supports camera power. CDN $156
Kendrick Standard Dual 4 Two separate controls. CDN $149
Orion Dew Zapper 4 Four controls! USD $150
Astrozap 4 Two controls. USD $105
PegasusAstro Dual 2 Two controls. Euro $99
Revelation Pro Dual 4 Two controls. Euro $90
Dew-Not Dual 4 Two controls. Green LED! USD $135

To name a few...

"Basic" units allow the level of heat produced to be set by manual adjustment. Some have additional features like low-voltage warnings or cut-offs, reverse-polarity protection, etc.

Kendrick and DewBuster and others also offer "advanced" units that accept temperature and humidity inputs so to automatically modulate power output. Set it and forget it. Some offer additional features like remote computer control, profiles, more power outputs, etc. Not surprisingly, the prices jump. Double or triple... Plus you need the sensors. Ka-ching.

I could build a basic unit for a quarter to a third of the price. Maybe less given the parts and bits and bobs that I have.

Thursday, January 10, 2019

Binary Universe: exploring exoplanets

I received my extract from Mr Edgar signifying the February 2019 edition of the RASC Journal was out.

cover of the Feb 2019 edition of the Journal
I look forward to reading Mr Rosolowsky's article entitled Invisible Light Pollution. There's a very interesting piece submitted by Mr Chapman where in 1966 Father Burke-Gaffney told the story of Mr Messier, with a twist. Mr Percy returns introducing us to the American Association of Variable Star Observers. I always enjoy his words.

In my Binary Universe column, I discuss my favourite exoplanet app. It exists for the iOS only and is made by a Torontian in his spare time. Exoplanet version 17.1.0 remains the most comprehensive and up-to-date of all with a fantastic immersive 3D simulation of all the newly discovered worlds surrounding us.

This entry marks my 25 contribution.

Wednesday, January 09, 2019

considered Rick's design

I remembered that London RASC member described a dew heater controller build project using an Arduino.

I was attracted to the design for its temperature and humidity sensing capabilities and considered that this might be a viable way to get into single-board computing field. I reviewed his article in the October 2014 edition of the Journal. The controller was also resilient to low voltage and offered computer control. But when I followed the web links, I got dead-ended. Reached out to the author Rick Saunders.

He quickly replied and said the unit "worked a treat." He warned about the heat generated in the controller affecting the DHT22 sensor. But then he relayed some bad news. He had suffered a hard disk crash losing a bunch of Arduino stuff.


A few days later Rick shared the found sketch and VisualStudio project. But I had also hoped to receive a formal schematic (versus his diagram in the article) and maybe the board layout.

I was having second thoughts... Between the first contact with Rick and receiving the found files, I had decided against the Arduino path. I knew would be more expensive (not a lot but more) and (probably) extremely time-consuming with a lot of learning required. I wanted something very quickly. And really cheap. A basic unit would do.

Tuesday, January 08, 2019

learned about Mass

Couldn't sleep. Finished reading Spaceman by Mike Massimino. What an amazing little book.

I started following Mike when I was monitoring the NASA shuttle missions. In fact, I remember watching the Hubble Space Telescope Servicing Mission 4 in 2009 where Mike... put some elbow grease into the repair! As I read the book I came to realise that he was one of the key people, in more than one way, for saving and extending Hubble. He helped us go deeper with the HST.

I remember his PR activities at NASA and his hilarious guest appearances on Big Bang Theory.

Humble, funny, self-deprecating, and smart. And deep. He's very altruistic. All that comes through in this easy-to-read book that I stumbled across and downloaded from the library.

What a cool guy.

Sunday, January 06, 2019

transparent skies (Bradford)

During a short walk, in the chilly northern breeze, took in the clear, rather dark skies. Orion rising. But Sirius was not yet visible. Pleiades up high. Mars was astonishing, intense deep orange. Noted the Swan diving into the north-west at the end. No meteors nor fireballs...

just an asterism

Checked the WDS for a multi-star system near or around HD 35038. From my Friday night observing session. Nothing. But I did note that SkyTools showed an open cluster marker at the location. The moniker is Dolidze 17. Huh. Now, that said, in the Object Information box ST3P stated "reality of cluster in doubt." Google search results returned some hits including references to an asterism.

looked into A 666

Had a look-see at the multi-star system A 666 (aka palindromic HD 42924). Pulled the current data from the Washington Double Star database... In particular, I was wondering about the bright star between A and C/D.

06133-0624A   666AB    1904 1995   14  28  37   0.6   0.5  8.91  9.47 G5
06133-0624A   666AB,C  1893 2004   13 318 321 229.1 230.1  8.91  9.25 G5
06133-0624A   666AB,E  1904 2015    4 232 234  24.4  23.8  8.91 13.76 G5
06133-0624A   666CD    1904 2016    7 267 265   5.2   5.2  9.25 14.8  K0

Ah. Found another star. An E companion. But when I reduced the data and plotted it (in my Excel tool), E showed up to the south-west. Oh.

plot of the 5 elements of multi-star system A 666

So I still don't have an answer per se.

And it suggests there's an E star to view... But I didn't log anything Friday night other than A and C. If the magnitude value of 13.8 is correct, it will need aperture.

And D? Hopeless probably at mag 14.8.

Anyhoo. The system in Monoceros remains on the View Again list. Should go after it with a big OTA to pull out the faint and tight elements.

another minion

Ha ha! Tom posted on the RASC Toronto forum, "Thanks to Blake (and Sissy Haas!) I have become a hopelessly addicted double star seeker!" Resistance is futile.

Saturday, January 05, 2019

tested no-name dimmer

Tested the cheapo dimmer controller I bought off eBay a long time ago... Friday night the dew strap on the camera did not seem to be working. I hadn't felt any heat of it. Tested it on the bench. Nothing!

Checked for volts coming out of the controller. Except when dialled down to zero, it showed over 12 volts DC. OK. After reviewing my notes, tried the little logic probe from Dietmar. It was showing pulses... at certain positions. A good sign. But nothing from 0 to about 10%. And nothing above 75%. Weird.

Put the Kendrick 2" eyepiece dew strap on the Kendrick controller. It immediately warmed at the low setting. Of course. Whew.

Then, out of curiosity, tried the old Micronta logic probe on the Kendrick. And just couldn't figure out what was going on! Anyhoo. The strap is fine. The Kendrick controller is fine. I'll have to do a deeper dive into the no-name controller.


Didn't know this at time but the 2" dew heater had a break in the wire 'causing it to not work at times. I believe during the dimmer test, the circuit was open, while during the Kendrick test, the strap wiring conducted...


In late-January, I found a blown fuse in the multi-meter. Possibly the fuse was dead during these tests giving me false readings.

Frank viewed STF 196

Great to see increasing interest on doubles. Frank shared an observing report on the RASC Toronto forum.
Here is a brief observing report for one of the stars on Blake’s December list, HR 577 (STF 196) in Aries.  This was easy to find last night, and I found a nice orange primary star with a fainter pair to the north, consisting of close 8 and 9 magnitude stars.  It looked like all 3 stars made a very nice sight in the field of view of my 8mm Plossl eyepiece (180x on my 100mm f/15 refractor) and it is definitely a nice target on a night of steady seeing.
That's fun.

shot a comet, viewed doubles (Bradford)

Suited up. Three layers (this time) on my legs; five layers on my torso. Even though it was not that cold out tonight...

In the first go-round bringing stuff out, I forgot my eyeglasses.

Did I see a meteor out of the corner of my eye?

Wanted to photograph comet 46P/Wirtanen with my barn door tracker. Readied the Canon 40D with Takumar 55mm f/2 lens on my do-it-yourself barn door tracker.

8:00 PM, Friday 4 January 2019. In the backyard. Different spot this time. Two-thirds of the way south, between the fire pit and the shed. Pretty good when sitting, the street lights were not as annoying. Needed to be a bit south-west so to get the comet. Impacted my Orion angles unfortunately. Neighbours had the blue-white decorative lights on the deck turned on; not home.

8:03 PM. Was shooting the area near the comet. Pretty good focus. Tweaked it a bit. No obvious trailing per se. One minute exposure. Tried 2 minutes.

Thought the humidity was pretty high. I wondered about power for the dew heating. I had considered using the sealed lead acid batteries but had not brought any out at this stage.

Noted a plane in photo. Ah. I heard it. Slight trailing. Rotation? I had not yet done a proper polar alignment... Ugh. More stuff needed. More steps. Ruminated for a while.

Fetched the power tank.

8:15. Attached the 2" anti-dew strap to the camera lens. Used my custom dimmer PWM control.

Performed a precise polar alignment with my new larger chart. The custom alt-az base on the barn door tracker works fantastic! Went quickly.

Checked SkyTools for the exact location of the comet. About 5½ off the nose of Ursa Major, west-south-west of Muscida. Captured more test exposures using Bulb mode. Two and a half minutes, it was super-bright. Ooh. I had turned the drive off. Back on now. Set to ISO 100. Tried another 2.5 minute shot at f/5.6.

Tried field identification comparing the photo to the SkyTools Interactive Atlas chart. Alt-tabbing was acting strangely on the netbook computer. Frustrated.

Realised I had forgotten to do the co-linear alignment check on the BDT. Oh well.

Realised I still had the 2x doubler enabled in ST3P. But I had confirmed my location.

Loosened the ball head and aimed the DSLR a bit higher. Tried another bulb shot.

8:43. Reviewed all the gear to do photography. Barn door tracker, medium tripod, camera, camera AC adapter, extension cord, GFCI power bar. Tether and computer and associated bits and bobs. Battery pack, dew heater gear. Oh and table and chair. Crikey.

Checked field again. Noted a pair at the edge, that had been further up. I didn't move enough. Adjusted the ball head again. Also did a slight counter-clockwise rotation. Programmed the interval settings in Canon EOS Utility this time.

The dew heater did not feel hot... I had the controller at maximum.

8:48. Checked the Oregon Scientific portable weather station. It showed 70% relative humidity. Ambient air temperature read as -2.7° Celsius. There was dew on the unit. Said there would be precipitation tomorrow.

Moved up again.

While waiting, I set up Charles's old Meade ETX telescope on the Mamiya tripod.
Instrument: Meade ETX-90 Mak
Mount: tripod
Method: star hopping
Car pulled in the drive.

8:59. Readied for another shot. Programmed a 5 minute shot. Powered the Meade ETX 'scope while waiting.

The camera was nearly centred on the star HR 3106.

Went to f/4. Saw trailing in the 5-min shot. Dropped to 2 minutes. Changed the ISO to 800. Changed to 1:30. Set the aperture in the EU app.

I heard the west-side neighbour outside. Their dog freaked out until they put it inside. Neither of the humans could control it.

Whiskey tango foxtrot. Astrophotography is so... challenging.

Totally blown out exposure. Stopped down to f/8. Tried again. Darker. Continued to try to get the exposure right...

Found the finder scope fogged on the little MCT. Forgot to cap it.

Rhonda came out to see what I was doing. Comet hunting. But "Cupid and Donner were gone," she said. She asked if I had seen any "inids." Nope. I hadn't been looking up much (sadly). Said they should be emanating from over the house. She thought the sky was grey. Indeed. Low transparency. Wondered where the Moon was; new phase! We talked about weird cinnamon-flavoured and pumpkin-flavoured beers. She asked if I had seen the "snowman" object. You bet. She wanted to put a carrot nose and button eyes on it. She said wouldn't mind returning if there was something really spectacular...

What was going on?! Brain fart. I was going the wrong direction with the ISO.

Finally got a satisfying result. Checked the histogram. Programmed for 25 shots.

Activated the three-panel telescope mode chart thing in SkyTools (the Visual Sky Simulation). Installed the ole Celestron Plössl 26mm eyepiece. Set the time sliders in the Night Bar.

9:36. Ready to start visual observing. Considered targets. I thought Cetus was gone. Andromeda? Below Cassiopeia... So portions were still visible, even though I was closer to the western trees.

Went to the shed for Rhonda's garden kneeling pad.

Grew increasingly frustrated. Hard-to-use finder, telescope-tripod height, object elevation, frickin' trees, high-priority targets out of range, bright lights everywhere, cold and damp, high humidity, old specs, bad eyes, finder out of alignment, a total manual 'scope, everything. Everything.

Reviewed a photo.

comet 46P near Ursa Major

Canon 40D, 60 seconds, ISO 800, daylight white balance, RAW format, Takumar 55mm at f/8, Canon EOS Utility, Digital Photo Professional 3.8, Paint.NET. North is left; east is down.

Panned around but finally landed at the Trapezium. Four stars visible. The nebula was spectacular.

9:56. Aligned the little 6x finder scope. It was way off.

Moved to 42 and 45 Orionis. Wanted to have another look at this wide pair.

10:05. Flattened triangle. Orange star, much dimmer, between them (aka V359). 42 was on the left for me, i.e. the west, in the little Mak.

I had added this pair to my list to view again. It is in the Astronomical League's binocular doubles list. But it was also included in Jerry Lodriguss's naked-eye doubles list. I tried to spot the two separate stars with my old fogged eyeglasses without success. ST3P said the stars were 4.25 arcminutes apart. [ed: Mizar and Alcor are 12.0' apart. And I find them somewhat challenging...]

With the 26mm (so 48 times). 42 looked yellow; 45 was dimmer... blue-white? Maybe? Or was it the same?

Forgot to bring out the binoculars. Easily split in the 6x finder. Pleasing pair, in lieu of bins.

There was dew on the screen of John Repeat Dance. Oregon said: 76%, -2.6°.

Upstairs neighbours got home. Their kitchen light flooded the back yard. Brighter now with the snow. I was a bit further away though.

Capped the camera and started a darks run.

Returned to Messier 42. To enjoy the spectacle.

10:14. M42 was very nice in the small f/14 OTA. Very nicely framed. Intense. The U-shape nebula, the grey cloud, was great. With the Trapezium at the bottom of the U. θ (theta) 2, in the string of 3 aligned stars, off to the right. Extremely large. In super-dark skies it would fill this field. Noted M43 (Messier 43) above, to the north. Small, surrounding a single star. The Great Orion Nebula has a large wing went off to the north-west. Quite big with averted. A tail that went to the south-west. Very nice. Big. Noted ι (iota) below (south).

For my next target, I started moving along the outstretched arm of the hunter. Starhopped from γ (gamma) Orionis.

10:32. Landed on a neat pattern of stars with HD 35038, a boxy C-shape.

[ed: Discovered SkyTools marks this as the questionable open cluster.]

Made it to 14 Ori. Oh boy. A super-tight fast-moving binary. About one second of arc between them. Too close to one another for the 90mm telescope.

Checked the camera. Five to go.

Headed inside for a bit.

Bagged the camera. Packed up the camera gear.

Wanted to revisit ζ (zeta) Persei. Hopefully to get more stars...

11:05. Saw the three stars. The two faint ones below. The D and E stars to the south. D was fainter of the two. A was pale yellow. Hard to get any colour on the dim companions. Maybe D was orange and E was blue. Noted the star opposite D, further out, at mag 10.3.

A bunny rabbit hopped by me, to the south.

Loaded the Pentax XW 20mm ocular. 62x.

The seeing was quite good.

Noted the pair to the north-east. HD 24601, the A and C stars. Two in the view...

ζ is on my candidate list.

Tried the Meade orthoscopic 18mm. Only slightly more powerful, 69x. Could not see any more stars.

Tried for κ (kappa) Leporis. Starhopped south from Rigel. The bottom-right star of a cup-shape with ι and λ (lambda).

11:25. Not a great candidate for my programme. Too tight. 2.3". ST3P said it was "not splittable" at any time. While not an overly difficult starhop, just too tight for a little 'scope.

Wondered about some other doubles in the rabbit constellation...

Oh. Red star! M-class. Went to ι with RX Lep right beside it. Nice. Arrowhead of stars. iota proper was a double but the B consort was 6 magnitudes dimmer and fairly close at 12". I peeked. It was to the north according to my software atlas but I couldn't see in the telescope. [ed: Previously viewed in early 2018.]

Viewed double HD 34071 aka GAL 378 near μ (mu) Lep.

11:36. Yellow and orange. Nice. Separation 38.6, mags 7.6 and 9.1. Ah. The primary was a K2 star.

Accidentally activated the Interactive Atlas. Dang!

Noted Sirius was twinkling wildly. Flashing into different colours like a police car cherry bar.

Took in the huge Winter Football.

11:42. Wondered about The Pup... Hmmm. Eleven arc-seconds away...

I had HR 2358 in my list, the C star of β (beta) Monocerotis. I decided to return for another look. Started my hop and landed at γ.

SkyTools said there was a multi-star system west of gamma. A nearly straight line of 3 stars. Quite faint. This was HD 42924 or A 666. Actually, the Object Information box revealed it was a quad with the B partner less than 1 arc-second away. The C sidekick was a mile away. OK, 230". C and D were too close for the ETX. Intriguing the star between A and C...

[ed: Reviewed the WDS data on A 666.]

Hopped using the ocular again... Carried on east.

When I arrived, I saw a tight double. Changed eyepieces, going from the 26 to the 20mm. No way!

11:52. Whoa! I split the B and C stars of β (beta) Mon! Wow! All the same colour... C was dimmer than B by a touch. B was a tiny bit dimmer than A. When I had the 26mm in I thought at first I was out of focus when examining the B star but it was because it was two stars! Fantastic. [ed: B and C are 3 seconds of arc apart! That's a useful number...]

Went back to the 26. I could see B and C separate! How about that! Amazing.

Now that's good seeing conditions!

Tried to coax out the faint D attendant. Nope.

[ed: Highlight of the evening, right there.] [ed: While I had seen the C star before, never in so small an instrument.]

Headed to Sirius. Looked for the B colleague. Used my flotilla of eyepieces.

Rhonda checked in.

Suddenly I felt tired. My disturbed sleep patterns of late were not helping. I was a bit cool in the torso.

12:10 AM, Saturday 5 January 2019. Done with Sirius. I kept wondering about diffraction mask tricks...

Starhopped from Procyon for 14 Canis Minoris. Somewhat tricky.

12:16 AM. A triple, also known as SHJ 87. Nice. Nearly equilateral triangle. The B and C stars were very faint. I wondered if this item should remain on my candidate list. Hard to get to, the companions might be invisible for some, nothing exciting nearby.

Started packing up.

There was a lot of frost. Checked the weather device: 82%, -2.6°.

Energizer head lamp light was working poorly. Low batteries presumably.

12:30. Hauled the marine batteries back to the house.

Enjoyed a night cap.


Edited 7 Jun '19. Changed 89mm to 90mm for the aperture of the Meade ETX.

Friday, January 04, 2019

good looking charts

Wow. Hadn't seen an optimistic Clear Sky Chart for a long time. The Clear Outside and Astrospheric charts echoed the good prediction.

Clear Sky Chart for Friday night

I considered observing in the back yard. Maybe I could multi-task too and try to image the comet as it headed toward the snout of the Great Bear.

Wednesday, January 02, 2019

lunar and solar phenomena (York region)

On leaving the house to catch the train, I spotted a very thin old crescent Moon. It grew increasingly difficult to see as it rose into a bright sky.

Later I spotted iridescent clouds. There was an extremely bright rapidly evolving spectrum of intense colour left of the Sun and close-in to the right mottled opalescent pigments.

On the way home, my heart sank as the high and low cloud cover increased. I had hoped to spot Venus naked eye near the Moon... Mr Markov had encouraged everyone to try.

Tuesday, January 01, 2019

happy new asteroid

Watched the Ultima Thule NASA media event live. Alice Bowman, Chris Hersman, Alan Stern, and Hal Weaver updated us on the New Horizons spacecraft and the data coming down. They shared the highest resolution image, so far.

early approach image from Ultima Thule

Early views support the bilobate shape, like a peanut or a bowling pin. Reminiscent of the rubber ducky shape visited by ESA. Amazing this view of the furthest and most primitive solar system object. And it's only gonna get better.

See the John Hopkins Pluto web site for more info.