Saturday, May 25, 2019

beautifully clear (Mississauga)

Uncle Tony popped out to the deck. Ha! Clear. After the rains. Spica. Big Dipper overhead. But too late to play. Oh, it was a little damp...

shot Barnard's longer (Halifax)

Reshot Barnard's star. Tripled the exposure time.

Barnard's Star

Luminance only, 3 second subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

That's better.

Thursday, May 23, 2019

visited Barnard's Star (Halifax)

Visited Barnard's Star with the BGO robotic system. This star in Ophiuchus shows very high proper motion. It is the brightest star, above centre. If I image it annually, I should be able to see motion against the surrounding stars. It's heading to the north.

fast-moving Barnard's Star in luminance

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

It's close. About 6 light-years away.

I'll try to image this annually for a few years...


Wikipedia link: Barnard's Star.

dropped in on 70 Oph (Halifax)

Commanded the BGO 'bot to capture 70 Ophiuchi again, the 88-year binary star. By aiming at GSC 00434 02340, this puts Σ2272 to the bottom-right.

fast-moving binary 70 Oph in luminance

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

This is the third fourth year of imaging! I'll have a go at detecting the orbital motion...

Annual image log:

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

I should attempt to measure the position angle in all these... Should see a change.

Wednesday, May 22, 2019

imaged xi Boo (Halifax)

BGO captured double-star ξ (xi) Boo (aiming at SAO 101256 to the east). Also known as Struve 1888, it is the bright pair to the right. It is a fast-moving binary system about 22 light-years away. 

double-star xi Boo in luminance

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

I intend to shoot this every May for a few years. The period is 152 years. Hopefully we'll see the orbital motion...


Now, when I first visually inspected this pair, I was after the colours. Σ1888 is noted in the RASC Observer's Handbook, the Cambridge Double Star Atlas, and the Coldfield list. Sky & Telescope magazine included it in an article regarding colours, if they were real or imagined.

Back in May 2008, I only noted the pair, A and B. Likely as that was all the information that I had to go on, at the time. It was before I started using SkyTools. Now, with ST3P, I know it is a multi-star system!

B is oriented to the west-north-west, tight, of course, to the primary.

The C companion is remarkably faint. I bet it is not visible to the eye at the ocular. It appears to the north-north-west, a good distance away. The Washington Double Star database reports it is mag 13.8.

Ally D is easily spotted, brighter than C. It is nearly inline with B, a touch further south, but further away than C. Two to three times the separation.

The E escort is opposite D, further out again. It is bright, possibly brighter than F. Maybe the same as B.

And finally the F star is to the north-east, the furthest. A tiny bit dimmer than E.

Cool. Wasn't expecting that...


Wikipedia link: xi Boötis.

aimed at Wolf 359 (Halifax)

I asked the Burke-Gaffney Observatory to image Wolf 359, a red dwarf star in Leo with very high proper motion.

star Wolf 359 in luminance

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

Whoa. Faint. Even though it's only 7.9 light-years away. I should have shot longer... Can you see it?! I believe the target is not dead centre; rather, it is the medium bright star near but right of centre.

Also, this star is best viewed in February and March, after 1:00. Goes over 45° in elevation. It was around 44 for me on this occasion. Conditions weren't great. The ECMWF indicator said there was 5% cloud. Transparency and seeing from the Clear Sky Chart were, respectively, average and poor (2/5).

The plan is to image this star annually for a little while. With a proper motion against the background stars of 4.7 arcseconds per year, I should be able to see the shift...


Wikipedia link: Wolf 359.

saw BGO fire up

Yes. Clear in Halifax. BGO was running and taking images. I had a few jobs in the hopper.

Sunday, May 19, 2019

measured AFOV

I just learned how to measure the Apparent Field of View (AFOV) of an eyepiece. It's super-simple!

Set up a rig and tested my 36mm 2" aspheric eyepiece. Quick and crude, I computed the AFOV at 71.2°. baader planetarium says it's 72.

field projection through eyepiece

Do you see the large faint illuminated circle?

We can use the technique to measure the antique ocular at the DDO.


Tip of the beanie to the Cloudy Nights article "eyepiece afov calculation" with discussion, diagrams, and photos as well as the CN article "flashlight test for aperture - illustrated" on using a torch.

tinted Moon with bright Jupiter (Bradford)

The Moon was full. And pale yellow. Weird. I wondered where the colour was coming from. Smoke? Cloud? Particulate?

screen snap from SkySafariDown and left a super bright pale beige object. Awfully near the ecliptic. Too low for Arcturus... Arcturus had to be bright orange star nearly overhead.

I was a little confused.

Check SkySafari on the Android (version 6, the free stripped-down edition). Right. Jupiter!

Antares should have been essentially below the Moon but clouds blocked the view during my short walk home from the bus stop.

Spica was visible to the south-west, dimmed by water vapour.

Too bad we had not had these skies at the beginning of the evening...

Saturday, May 18, 2019

helped at DDO

Helped at the David Dunlap Observatory tonight. Chris was away so Denise and I delivered the dome tours. We had two groups. I did the first stint with the first group. We decided to flip-flop for the second tour but handed off to Denise so I could debug the balcony dome interlock issue.

Sadly, we were clouded out. But, that gave me an opportunity to see the slightly different programme when we did not open the shutters.

We had one of the best turnouts, with 58 guests showing up.

We had a decent number of volunteers, in the end. It was fun seeing Risa, first time in a long time.

I'm very grateful to Ron, once again, for carpooling.

A couple more hurdles crossed.

Wednesday, May 15, 2019

monthly doubles for May 2019

Sent out my double star "bulletin" for May 2019. It is a short list of suggested targets. I shared this on the RASC Toronto Centre forums. And I post here for all.


Whoop. Snuck up on me, this impending full Moon. :-( Rather than mope, check out double stars! :-) Double and multi-star targets you can observe them any time, anywhere, regardless of light pollution.

Here's a selection of doubles I find interesting and impressive. Targets for May:

staralso known asalternate catalogue(s)
HD 112733 CVnΣ (Struve) 1702HIP 63317
24 ComSTF (Struve) 1657SAO 100160, HIP 61418
35 ComΣ1687SAO 82550, HIP 62886
δ (delta) CrvAlgorab, SHJ 145SAO 157323, HIP 60965
HD 111398 VirENG 49SAO 100279, HIP 62536

Why don't you add these to your observing list and have some fun! I look forward to hearing how you make out. Any questions?

Blake Nancarrow
astronomy at computer-ease dot com

Sunday, May 12, 2019

Binary Universe: measuring darkness

cover of the June 2019 RASC Journal
Saw a Facebook post announcing the June 2019 edition of the RASC Journal.

Kersti's aurora photo was featured in an article on the Astroimaging Certificate Program. Mr Percy has a piece of computing technology which I very much look forward to reading. Blair has another entry for processing images, this time for dealing with bloated stars. The cover alludes to an article on the black hole inside M87.

In my Binary Universe column, I discussed how to formally measure sky darkness in lieu of using a Unihedron Sky Quality Meter by employing the inexpensive iOS app called Dark Sky Meter, version 2.9.9.

Saturday, May 11, 2019

poster of the Moon

Also included with the DAO book and Mars article from my sister, there was a poster. This is entitled Earth's Moon and it is from the cartographic division of the National Geographic Society. It looked very familiar...

Nat Geo Moon poster (new edition)

I believe I had this same poster as a youth, during high-school. This appears to be new, in very good condition, although yellowed in age. It is dated 1969!

an old Mars article

Inside the DAO Star Maps booklet from Donna, I found a newspaper article on Mars. Positioned in the Sickle of Leo, reaching opposition on February 11.

Mars in the news

The subtitle suggests this predates 2003. Using Stellarium, I determined this was the 1995 apparition of the red planet. I suspect the article (from page D8) was written in February '95.

The piece is by Martin Beech, noted as "a London-based freelance science writer." Perhaps this article is from the London Free Press.

received DAO charts

Sis gave me an interesting book (booklet?).

DAO star maps book cover

It is a collection of star maps from 1956 prepared by the Dominion Astrophysical Observatory. Back then, the DAO was part of the Canadian Department of Mines and Technical Surveys.

DAO star maps book inscription

There's an inscription on the inside. "To Miss Chapple With best wishes from G. J. Odgers. April, 1959."

DAO star maps book sample chart

There are a pair of charts from each month, looking north, and looking south. They represent the sky from a location at approximately 50° latitude, in the middle of the month, at around 10:30 PM.

observing from bed (St Thomas)

The blinds in guest room don't quite go down all the way so when I turned the light out, I could see a slice of the southern sky. I noted a single bright blue-white star. Too low of Vega. Must of been Spica. And... sleep!

Friday, May 10, 2019

viewed Luna in the Beehive (St Thomas)

The weather suddenly improved!

Donna had relayed my ask of Steve. He brought over his birding rig, a Celestron 60mm 25x porro-design spotting scope and Manfrotto tripod with window clamp. I set it up on Mom's back deck.

We viewed the half-lit Moon passing through the Beehive cluster (aka Messier 44, M44). As bunnies hopped about. The orb was bright but we enjoyed the earthshine and the two to three dozen stars. When we put the Moon out of the frame, the stars popped. That helped as we looked over the city through light-polluted skies.

Hmm. Some tantalising pairs. I wondered if there were some double stars within...

Very nice.

I was tempted to stay out for a while so to watch Luna creep past stars but it was a little chilly and everyone wanted to go back inside. I agreed.

Thursday, May 09, 2019

shared TheSkyX materials

astronomer friendly - quick reference card
For the CAO supervisors, I did a bit of configuring in TheSkyX in the Geoff Brown Observatory to mimic some of our old settings (e.g. slew configuration; NE indicator). Reviewed Steve's notes. I posted my quick reference cards in the Yahoo!Groups and put copies on the desktop of the GBO computer. One of the versions is red on black!

For myself, I put the files in Andromache and John Repeat Dance. I copied the content into Evernote.

to identify celestial objects

A short time ago, I received a message from a reader, Peter in Ottawa, regarding sky viewing apps.
I read your April column in the RASC [Journal] with interest.  I'll probably get the [Astro Clock] but what I'm looking for is a program for my portable device to give me a view of the night sky in real time as I point up in different directions, with names of planets, stars and nebulae.  Those visible to the naked eye and binoculars.
I apologised for the delay and recommended SkySafari for its augmented reality and identification features.