Friday, January 19, 2018

stuck roof

Last night, it sure looked like it was clear over Halifax. I thought the BGO would start up...

The Clear Sky Chart showed a long run of dark blue in the afternoon. I received an email from the Clear Sky Alarm Clock system. The Twitter feed showed activity around dinner time. Sonoran Skies pulled a weather map. It showed clear at the moment. The 'bot reported it was "waiting for the sky to clear..." In anticipation, I updated my staging list in SkyTools 3 Pro on John Repat Dance. But at 7:09 PM EST, still nothing.

Clear Outside forecast for Thursday night

Later, I double-checked the weather reports. Environment Canada said some clouds while Clear Outside showed good at midnight through to morning. But no email alerts arrived.

In the morning, Burke-Gaffney Obs tweeted
oh rats...the #human checked the logs and last night the dome froze in place again so my run failed to start. #human, do a better job this time pls!!!
Stoopid ice pellets.

Sunday, January 14, 2018

identified ARA 752

Researched the pair to the west of U Sagittarii S imaged on 7 Aug '17. Tried to figure this out on 10 Dec '17 but ended up confused.

SkyTools calls this ARA 753 but that's incorrect. This pair is located at 18h31m29.2s by -19°05'12". ST3P says the pair magnitudes are 10.94 and 13.1. Again that doesn't seem right; the secondary star in the image looks brighter. The photo shows a position angle like 285. The separation is more than 5", maybe around 8 or so.

I searched the WDS around 183129.2 and -190512.

Found WDS 18315-1905 ARA 752. In 2010, the PA was 284 and the sep was 10.9. The quoted mags are 11.00 and 11.6. The precise location is 183129.22-190512.1.

sorted ARA 753

Reviewed double star ARA 753 imaged in August 2017. Tried to sort this 10 Dec '17. I compared data from SkyTools 3 Professional and the Washington Double Star database.

PA sep year A B RA dec notes
ST3 173 5.5 1919 10.94 13.1 18 31 29.3 -19 05 12 does not
match photo
WDS 176 5.8 2010 10.62 11.1 18 31 30.97 -19 03 43.3 does not
match photo

The bright pair to the north-west of the S star of U Sgr which ST3P refers to as GSC 06274-1098.

PA sep year A B RA dec notes
ST3 178 6 - 10.1 10.1 18 31 31.0 -19 03 43 north
star
ST3 - - - 10.1 10.1 18 31 31.0 -19 03 49 south
star
WDS 176 5.8 2010 10.62 11.1 18 31 30.97 -19 03 43.3 matches
photo

So, I think I have figured this out. It looks like ARA 753 is the bright double north-west of S and it looks like ST3P is wrong. And therefore I think I have in fact split this particular double.

SkyTools calls ARA 753 the pair to the west of S. But the position angle and magnitudes don't match.

Saturday, January 13, 2018

Binary Universe: asteroid occultations

cover of the February 2018 RASC Journal
Recently received the notice about the RASC Journal. The February issue was ready for members to download.

Malcolm Park got the cover.

Looking for to the articles by Sage, Percy, and Levy.

My software review column Binary Universe featured the Windows asteroid occultation prediction tool called Occult Watcher. By monitoring shadow cones for your area, you can hope to witness or record an occultation of a star.

Thursday, January 11, 2018

over 1200

Broke 1200 attempted double stars last night.

finished on HR 3701 (Halifax)

I wanted to revisit the multi-star HR 3701 aka Struve 1338 to track down the C element. The BGO robot obliged and captured the target in Lynx. Something is visible to the south-west... But I don't know what it is.

multi-star HR 3701 in luminance

Luminance only, 3 seconds subexposures, 20 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

Viewed this triple on 14 Apr '17 and had split the tight AB pair. But the third companion eluded me.

SkyTools 3 Pro shows C to the south-east. On the Interactive Atlas chart is shows as bright, mag 11.4. But in the photograph, while it has the correct separation, appears very dim, about the same brightness as GSC 02991-0543 which ST3P says it mag 16.2. No wonder I couldn't see anything!

The Washington Double Star database shows very interesting information!

A and B are at a PA (theta) of 311° with a separation (rho) of 1.1" (as of 2016). ST3P is similar: 320 and 1.0 (calculated for 2019.2).

A and C are 166° and 144". Wait! What? ST3P says C is 167° and 10"! Oh. I see. That medium-faint well away star to the south-south-east is what the WDS says is the C star. So then, no problem, I've seen it, check. And it looks like the data in SkyTools is wonky.

But then, what's this super-faint thing about 20" away hovering around PA 195° at mag 16?!

Wednesday, January 10, 2018

spotted HD 36073 B (Halifax)

BGO robot imaged HD 36073 aka β891. This is a multi-star system in Taurus at the outer edge of Collinder 65. When I first tried to observe in 30 Mar '13 I did not meet with much success. In this image, I can see the B star of the quad. w00t!

multi-star system HD 36073 in luminance

Luminance only, 4 seconds subexposures, 20 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

The B star is very faint compared to HD 36073 A. It is to the east-south-east of A. Delicate. C is the bright star to the north. But I cannot split C and D in the image. Then again, they are very tight, at less than 2 arc-seconds. I've still not spotted D so I'll leave it on my View Again list...

HD 35985 is to the south-west of Burnham 891, equally bright. I split the tight pair back in 2013 but they just look like a rod or elongated blob here.

South of BU 891 is HJ 3274, a tantalising faint equal pair. Also previously split.

HD 62679 in M93 (Halifax)

HD 62679 is a double-star inside the open cluster Messier 93 (M93). It was on my View Again list with a note "consider imaging." BGO to the rescue (with the minimum altitude setting decreased to 20). Happily, I spotted the B companion of the pair in Puppis.

double-star HD 62679 with Messier 93 luminance

Luminance only, 5 seconds subexposures, 20 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

First viewed on 21 Mar '12 from the Overlook deck in Toronto. Split on 7 Apr '12 from Carr Astronomical Observatory atop the Blue Mountains.

HD 62679 is arguably the brightest in the cluster, south-west of centre. The B element, while much dimmer, is clearly visible to the north-west of A. An issue from the visual attempts in 2012 was that the companion was much fainter than what the software SkyTools said. Certainly the B star is dimmer than GSC 06540-3094 to the east and it is magnitude 11.9. B is very similar in brightness to GSC 06540-2578 to the south-east which is mag 12.4. So, we can put this one to bed.

South-east of the parallelogram of stars and the right-angle triangle of stars is a faint wide pair, vertical oriented, i.e. arrange north-south. This is ARA 2069. SkyTools says they are both magnitude 10.1 but B is fainter by about 1 unit.

There are other doubles within M93 but I cannot split them.

And there are other pairs and triples that look obvious but are not marked in the software.

§

Wikipedia link: Messier 93.

learned of fake meteors

Flipped to Discovery Channel while winding down dinner. It's Future Tech Week with crew at the CES show. Caught a segment on proposed artificial meteors by ALE. Don't know exactly what to think about this...

It makes me think of the things you can put in a camp fire that make interesting colours. How popular would this become? I suppose that will largely be a function of the price. Would they release these willy nilly? Would there be any date or time restrictions? The biggest negative, as I see it, is how it would ruin many astrophotographs. Will it destroy the natural beauty of a dark sky? We already have thousands of active and dead satellites up there.

Found an article on the National Geographic web site.

imaged Struve 2902 (Halifax)

An hour and a half after starting up, the Burke-Gaffney Observatory imaged double-star HD 212468 aka Σ2902 in Lacerta. It is a beautiful but tight double from the Coldfield 200 list.

double-star HD 212468 in luminance

Luminance only, 5 seconds subexposures, 20 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

A and B are nearly the exact same brightness. Very close. Touching in the image. SkyTools 3 Pro says the separation is 6.5 seconds of arc. Lovely.

Bonus double star? Included in this image, to the extreme north, at the top edge of the image, is the fantastic unequal pair of BD +44 04117 aka ES 104. The very faint B partner is north of bright A.

Monday, January 08, 2018

next meeting announced

Once again I was wondering what was up with the RASC TC council. Tom sent a note out on the forums.
RASC Toronto Centre council will be holding a council meeting at 7:30 PM on Thurs Jan 18 in the Petrie Science and Engineering (PSE) building at York University, rm 258, 4700 Keele St.  Members are welcome to attend, please reply to this post if you intend to do so.
There ya go.

Sunday, January 07, 2018

available early

BGO sent a message that the images were ready for processing. At night! Is this a new feature? Normally they are not offered up until the next morning. I suspect it is more likely because the imaging run stopped short.

imaged 16 Eri (Halifax)

Loaded a double-star job into the BGO queue for the bright Moon phase. Aimed at GSC 05878 0248 and the robot imaged 16 Eridani also known as τ4 (tau) Eri.

multi-star 16 Eri in luminance

Luminance only, 2 seconds subexposures, 20 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

Neat system with 6 stars.

B is not visible, lost in the glare of the brilliant primary. Doable at 6 seconds of arc. Looks like I'd need to shoot much faster, a half second perhaps, to split them.

The C companion is to the south-east or down and left of the main star. It is the brightest of all the members.

D, E, and F are on the west running from north to south. D and E are equally bright. F is brighter than D and E but less so that C.

This is an old multi-star system. Well, old in terms of human observations. Reports date back to 1887.

...

Wikipedia link: Tau4 Eridani.

updated DS plotter

I updated the double star plotter in Excel. Version 3 now supports different orientations i.e. east can be left or right.

snapshot from Excel double star plotter v3

This is becoming very useful...

Thursday, January 04, 2018

found OMVDS2

Stumbled across Observing and Measuring Visual Double Stars (Second Edition)! I thought for a long time it was in a moving box somewhere. When I did not spot it while looking through boxes over the Christmas holidays, I started to get nervous. Had I lost it? Left it somewhere? Then, while switching out the Observer's Handbooks, I found it with my gear! OMVDS was in astronomy box α prime. The whole time... Whew.

Wednesday, January 03, 2018

relaxed CSAC settings

Relaxed the Clear Sky Alarm Clock settings for the BGO - Halifax location as I was not receiving, in general, email alerts on nights whenever the robotic telescope was planning to fire up. I.e. my parameters were too restrictive.

updated GRS position

Changed the Jupiter Great Red Spot (GRS) position in SkyTools to 280 as per the data from JUPOS.

returned to NGC 3521 (Halifax)

Commanded the BGO robot to photography NGC 3521 again. One of the first Finest NGCs I tried to image (back in March 2016).

spiral galaxy NGC 3521 in luminance

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

§

Different framing too. Using the new, smaller frame dimensions...

looked into The Eyes (Halifax)

BGO imaged NGC 4438 (centre). A fantastic galaxy in Virgo, it shows a huge halo greatly distorted by the nearby galaxy 4435. Not surprisingly, it is in the Arp catalogue, number 120. The cores of these galaxies are very bright. This target is another of the RASC Finest NGCs. Many call the two together "The Eyes."

Ugh. A lot of gradient unfortunately. And the bright Moon was 63° away.

RASC Finest NGC target with 4438 and 4435 in luminance

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

The central region of NGC 4438 shows dust and mottling. Really interesting.

To the north-west, I can see a small round fuzzy. This is LEDA 169314, just below star J122716.5+130838.

South-west of the big galaxy is a faint oval ball of lint: LEDA 169320. It is in the outskirts of the wisps of NGC 4438.

PGC 40890 is south-south-west of the warped spiral. It is faint and small and does not look completely round.

PGC 40915 is a small almond shaped fuzzy south of a pair of stars with J122743.1+125233.

East of the pair is a round diffuse shape but it is not marked in SkyTools.

Nestled in the bright stars south-east of centre is the somewhat large elongated smudge of PGC 40958.

Much further away, in the bottom-left corner of the image, is a large round fuzzy. This is IC 3388.

And to the north-east, well away, there's a small oval lint thing: PGC 40981.

I think there are many faint and small galaxies in the neighbourhood.

Near the centre of NGC 4438, to the north-east, there's a faint streak. I don't know what this is. Asteroid? Cosmic ray? Background galaxy?

§

Wikipedia link: Eyes Galaxies.

imaged NGC 4388 (Halifax)

The Burke-Gaffney Observatory imaged edge-on galaxy NGC 4388. Located in Virgo, this spiral has some interesting structure near the core. Large diaphanous disk. One of the RASC Finest NGCs.

RASC Finest galaxy NGC 4388 in luminance

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

There is a triangle of small and very faint fuzzies north (above) the big spiral. SkyTools 3 Pro shows two of these, PGC 40611 to the east (left) and PGC 40577 to the west. The southern one is not IDed.

NGC 4387 is the bright but small oval elliptical to the extreme north (at the top edge of the frame).

To the north-west, near star GSC 00880-0593, is a faint round smudge: LEDA 169262.

Diffuse IC 3303 is to the west-north-west of NGC 4388. It looks like a canted spiral to me; ST3P says it is a lenticular.

PGC 40519 is the somewhat large but very faint oval to the west-south-west.

The brighter, smaller concentration further along is LEDA 169248.

To the south-east there is a large, round, but very dim ball. This is MCG 2-32-45.

And to the north-east, far away, is a small oval fuzzy: LEDA 169283.

First viewed NGCs 4388 and 4387 back in May 2013.

§

Wikipedia link: NGC 4388.

Tuesday, January 02, 2018

returned to NGC 1232 (Halifax)

I wanted to improve on the data quality for NGC 1232, first captured on 21 Dec '17. This result is better, despite the bright Moon, as there is no satellite trail. Stretched it in a different way which increased the contrast.

face-on galaxy NGC 1232 in luminance

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