Friday, July 21, 2017

collected data for SLE 235 D (Blue Mountains)

10:15 PM, Thursday 20 July 2017. I wondered when my target would hit the peak. I recalled it was around midnight. Turned on the horizon and meridian lines in SkyTools 3 Professional to check. Set the Interactive Atlas chart to Real Time then toggled it off. Moved forward. Yep. Around midnight it would move into the western hemisphere.
Instruments: Celestron 14-inch SCT, Tele Vue 101 refractor
Mount: Paramount ME
Method: Go To
I also wondered about the visibility, with respect to the roof gable of the Geoff Brown Observatory. HD 172825 was a decent distance from Polaris so was there the possibility it would be behind the roof line. In SkyTools, I noticed the horizon line was smooth. I thought I had made a profile for the GBO. Switched to the other computer to display the simulated horizon line with GBO intrusions.

Noted my target was along the neck of the Dragon, as per ST3P, roughly between Grumium aka ξ (xi) Draconis and Nodus Secondus aka Altais aka δ (delta) Dra. I had to zoom a bit to the appropriate level but TheSky showed this well above the roof. Yeh. The altitude was around 60 to 70 degrees. Oh, no problem at all.

Reviewed the operational setup. The CAO laptop driving the Paramount was OK. And using it to remotely operate the Optec TCF-S focuser was OK. That offloaded tasks from the ASUS netbook which would be consumed with image capturing. Made a note to close all the browser tabs. Closed Evernote on John Repeat Dance.

Quickly planned out things. If the target crossed the meridian a little after midnight, I could begin my integration and setup around 11:00 or 11:30. I could have everything connected before midnight and do focusing. After midnight, in theory, the sky would be darker. Did some other things in the meantime.


11:30. Considered focus control. I found the custom Optec cable. I found long serial cable. I popped the screen a bit and passed it through the window. I would need the USB-serial adapter. Checked the assigned port: COM7. Adjusted the Optec software, connected, and tested operation. Put it back into Auto mode.

Closed unneeded apps on the netbook computer. Activated Super Performance mode.

Readied for camera control. Hooked up my USB-ethernet 2.0 extension kit (with power supply) with the subterranean cable. Attached the 2" nosepiece to the 40D body and connected the DC coupler. Hate the Canon power supply design. Bolted it up to the SCT 'scope and powered it on. Oops. Forgot the USB cable...

11:48. EOS Utility launched once I had the cable in place. Huh. Nothing. Tapped the shutter; it seemed the camera had gone to sleep. Switched the body to Manual to allow Live View at the computer.

Went to the camera, turned on the back display Live View, adjusted the exposure settings, ISO, white balance, a longer exposure time, and did crude focus, still on Sabik, with the telescope's mirror control. Forgot how easy that was to do, at the camera.

Operated the Optec software, starting from 3528, using the Dell computer, while monitoring the image on the ASUS computer (and external monitor). Everything was working just fine. No issues. Went down to 2528; went up. I thought it better when I went down. Stopped at 3328.

My target star was very close to the meridian. Slewed to a brighter star. Watched closely for cable binding. Wow. Nearly straight up. Bonkers.

12:01 AM, Friday 21 July 2017. Noted the Kendrick controller was now sending power to the objective dew heaters.

Pointing was off a bit so I manually panned. The refractor and SCT were fairly well-aligned. Decided on the 5mm eyepiece so to reduce the field, to make the 101 act as a finder. Opened TheSky's motion control dialog box. Fine-tuned the refractor alignment. Noted nearby the two sets of wide pairs, with HD 163769 on the west, and PPM 36276 on the east.

Now HD 172825 was over the meridian.

Initially, for me, the camera view was upside,-down, north was down, almost straight down.

Gauged the pointing off-set in TheSky versus the camera view. Chose Orientation, Zoom To... Used Telescope (Ctrl-t) and Finder. The Finder was too wide. The Telescope field (on the long edge) was 1 degree. The telescope was pointing slightly above. The offset was not bad: a fraction of a degree. 8 arcminutes. Rotated the field in TheSky. Put north down. Activated the camera field in SkyTools.

Adjusted the camera settings in EOS Utility.


Except where noted, all photos were shot with a Canon 40D, daylight white balance, on a Celestron SCT 14-inch, f/11, atop a Paramount ME, Software Bisque TheSky 6, unguided. Initially manually focused using the SCT mirror shifting control.

These first few preparatory images were shot using ISO 1600. Initially used Canon EOS Utility. All the images were processed using Canon Digital Photo Professional (DPP) 3.8. All images are oriented north to the top and east to the left unless noted otherwise. Lots of hot pixels. While dark frames were shot, none were applied to these images. Remember to click on images to enlarge; right-click to view in a separate tab or window at full size.

Performed crude focus and telescope(s) alignment with γ (gamma) Draconis. Did a test shot.

multi-star Etamin or gamma Draconis

12:11 AM. Gorgeous Etamin (aka Eltanin and Burnham 633). 10 seconds.

This is a multi-star system with 7 elements. The primary star is a lovely gold. B is faint, to the south-east, very close to the bright main star. Is it gold too? Or is that colour coming from the host? C is a very pale, dim partner to the south-west. It is the faintest star in the group. D is to the north, further out, and only slightly brighter than C. The white comrade E is beyond C, about the same brightness as B. Ally F is pale orange, further out still, to the east-south-east. Lastly, beige G is above or north-north-east, the brightest off the squad. Very cool to spot all the elements.

Searched for the star in TheSky using the SAO designation and manually accommodating for the offset. Did more checks and tests with my main objective, HD 172825 (aka SAO 17961 and HJ 2836A). I'm after the D companion...

multi-star system HD 172825 in Draco

12:22. 10 seconds. North is down; east is right.

I was happy to spot all the elements. Good correspondence with SkyTools. See below for the identification of all components.

Checked the infrared black and white satellite imagery. It was looking fine over Ontario.

Made a reminder note to get darks, at the end. Opened Evernote on the laptop to review my double star shooting notes (since the ASUS tablet was screwed up). Right. Do the "squaring" step...

Turned the camera in the focuser and did some manual drifting to better align the camera frame. A long run given the proximity to the pole. Used the grid in EOS Utility.

Ran a stopwatch app on Ananke to measure the full drift time. Figured out the timing: turn off tracking (a couple of seconds), expose (for 2:15), turn on tracking, slew back to the (previously selected) starting point (couple more seconds), wait for the next shot (about 10 seconds). Put the camera in bulb and programmed the interval to 2:35. Captured the multiple long exposure trails, using Etamin once again, using EOS Utilities script controls. These images will be used to measure the camera's orientation against the sky's declination.

trailed star to measure camera orientation against declination axis

1:20. 135 seconds. Pretty good alignment on the long axis. I'm not sure which way north is. Shot 15 images.

I just love the look of these traces...

Reviewed the process:
  • I ended up monitoring TheSky (that was better than watching the timer in EU). 
  • As the 'scope indicator drew near the edge of the frame. I would glance at the EOS Utility. I'd see the exposure timing around 2 minutes or 15 seconds to go. 
  • I'd return to TheSky. 
  • I'd choose Telescope, Options and hover the mouse pointer over the Tracking command. 
  • A quick glance at EU would show it the exposure time of 2:03 or so. 
  • Then I'd listen... When I heard the camera shutter close, I'd click the mouse, to turn the tracking on. 
  • Immediately, I'd hit the Slew button (using the previously selected point) and confirm the action to return to the start point. 
  • I'd choose Telescope, Options and hover over the Tracking command again. 
  • I'd watch EU count down to the next shot. About 8 seconds to go.
  • At 2 seconds before, I'd click the mouse, turning the tracking off.
Switched to Backyard EOS for advanced focus control. Operated the Optec TCF-S via the computer app again. Shortly after I activated the Frame & Focus, the FWHM showed a value 6.5. Curiously, as I adjusted the focuser, I never got a better value. Funny. Ended up back at 3328. Got a 6.7 at 3338. Went back to 3328. Remembered to put the focuser back to automatic.

Stayed in the BYE tool for its advanced filenaming and scripting controls.

Remembered to drop the ISO to lower the noise in the subsequent images.

OK. Next up was the image scale calibration stars, starting with ω (omega).

double star omega in Draco

1:52. Also known as 28 Dra and SAO 17576 and FOX 203. 10 seconds.

A is pure white. The B companion is very faint, a fair distance away, to the 4 o'clock position, or west-south-west. Also shot it at 20 seconds. BYE said the camera sensor was 29°. Shot it at 5 seconds and I could still see the B star.

The FOX 167 entry on the list seemed strange. Not sure how it got there.

Next up was Grumium. Couldn't see the companion so I shot a longer exposure.

double star Grumium in Draco

2:03. AKA ξ (xi) Dra, 32 Dra, SAO 30631, and LDS 1457. 20 seconds.

The main star is a pale gold. If I'm interpreting things correctly, the B colleague is the dark orange star to the west-north-west, well away. Really far. ST3P presents a chart that is different than the image. It's either bad data in the app or a bunch of these stars are moving around... Fascinating in any case.

Headed to T Dra, a M-class variable star. That is not a hot pixel.

variable and double star T Dra

2:07. aka HIP 87820 and ES 20. 10 seconds.

Wow. What an amazing colour! That might be the deepest orange-red star I've ever seen. The B partner, nearly equal in brightness, is close by, to the south-west. ST3P says it is also a variable, UY Dra. Wow.

I used the HD feature in Frame & Focus for the first time. It reminded me of the integration feature of the MallinCam, doing on the fly stacking.

Our next destination was HD 164330, a triple.

multi-star system HD 164330 in Draco

2:13. Other designations include: SAO 17695 and STT A 163. 5 seconds.

The primary star, near the centre of the photograph, is a beige or grey colour. The equally-bright B friend to the north-east is blue-white. Due north, well away, is the C star, dim, same colour as A. Also shot at 2 seconds.

Headed to HD 164984.

multi-star system HD 164984 in Draco

2:22. Other labels: SAO 17717 and Σ (STF) 2273. 10 seconds.

This might appear, at first glance, a simple pair. "Moth Eyes," as it were. But if you look closely, you'll see faint companions. SkyTools shows this to be a 4-star system. The A star is to the left or east. It is a pale blue-white. B is very slightly dimmer. And has a touch less blue. Further west, but at the same angular separation as A and B, is faint C. It looks grey. For bonus points, look near A and B, slightly north, to tag P, the very dim fourth star.

Lots of other interesting colourful stars in the field.

Took the big dew cap off to reduce wind-shake. From the floor I noticed clouds! That explained why some of the exposures were wonky. One shot showed a lot of vibration.

Did some shots of the main goal, HD 172825, in case the sky turned bad. Got the D star. Programmed a run for 5 images. Was feeling a little tired. Took stuff to the house. Some images were faded with clouds; some were shakey.

Slewed to HD 238823. A delicious treat. A quadruple.

multi-star system HD 238823 in Draco

2:38. SAO 30778, PPM 36404, or Σ2300. 10 seconds.

A is the brightest star, of course. Blue-white. It is on the right or west side of the group. B is the next brightest distant furnace, tan in colour, along the north edge. Below and tight to B is the delicate little C element. Not directly south of B, it is slightly west. Finally the D star is to the east. Hint of orange. About the same intensity as C. An amazing little collection.

There's a red dot about the D star. Sorry. Hot pixel. Please ignore.

Neat system.

Had trouble finding my next Skytools suggestion in TheSky so I moved on to 36 Draconis.

double star 36 Dra

2:43. HR 6850, HD 168151, SAO 17828, PPM 20819, HIP 89348, and STT 586. 5 seconds.

A simple wide double. A is white. B is far away to the west, pale orange. Also shot at 2 seconds.

Skipped to HD 170508. There seemed to be clouds again as I could not see the stars in the HD view. Peeked outside. Wasn't terrible.

Checked the weather conditions. 10-minute average was 6.4 out of the SW. The immediate wind speed was 8 with a high of 22.5. Humidity 94. Pressure 1011.9, still falling. Temp 19.2, dew 18.2.

double star HD 170508 in Draco

2:50. AKA SAO 17882 and ES 2666. 2 seconds.

An easy faint pair with robin's egg blue and grey stars. B is due west.

Next up: HR 6979. Could not see anything at first.

double star HR 6979 in Draco

2:55. Also referred to as HD 171653, SAO 17912, and KUI 86. 5 seconds.

Another pair of stars. The host is blue-white while the partner is a very dim white to the north-east. Is B greenish?

The astronomical twilight would beginning around 3:45.

Centred on HD 172323.

double star HD 172323 in Draco

2:59. AKA SAO 17936 and STF 2365. 5 seconds.

White and orange stars with the dim sidekick to the north-north-east. SkyTools makes them look nearly equal in colour and magnitude. Nope.

Came to the main target in the observing list so gathered more data. Could see the B, C, and D stars in the 5 second shot.

Found dew on the corrector even with the dew heaters running. Grabbed the hair dryer to clear the fog. Switched the controller to our winter configuration.

Off to 46 Dra, a wide triple. Bright stars in the area.

multi-star system 46 Dra

3:08. HR 7049, SAO 31119, and H 6 37. 5 seconds.

Bright A is blue-white. B is a good distance away to the south-south-east, dull white. C is opposite B, double the separation, and is brighter. It is a very pale peach. Curious. Why wouldn't the star to the south, with the same brightness as C, almost the same sep., not be considered part of 46? Or the orange star to the west? Oh well...

Selected the double SAO 18068.

double star SAO 18068 in Draco

3:21. Also known as ES 2669. 2 seconds.

A very faint pair. A pale orange primary and a faint white secondary, close, to the south. It was very obvious in the 5 second exposure.

Targeted triple HR 7191. Shot for 1 second. Shot again.

multi-star system HR 7191 in Draco

3:14. HD 176668, SAO 18082, and Σ 2440. 2 seconds.

The leader is off-white or beige. The second point is at the 8 o'clock position or east-south-east, close. It might be a light yellow or very light orange. The third member of the group is a good distance away to the north-east, slightly dimmer than B. Also whitish in colour.

Went to the faint pair PPM 21295. Short slew. Had a hard time seeing it in Frame & Focus.

double star PPM 21295 in Draco

3:17. The Washington Double Star database designation is MLB1082. 5 seconds.

A is blue-white; B, to the north-east, is a dull orange. Also tried 4 seconds.

If passengers would look out the forward port window, they will see Altais or δ (delta) Draconis. I could see the B in a 5 second exposure.

double star delta Draconis

3:21. SkyTools calls this target Nodus Secundus. Other designations are 57 Dra and BUP 186. 20 seconds.

This simple double is comprised of the very bright, yellow component with the dim nearby white star to the north. Why the other stars aren't included is beyond me. Regardless, a lovely field.

I thought it odd that the star GSC 04444-1629 did not show in the image. SkyTools plots this mag 10.6 star to the south-west.

[ed: Learned in 2020 that Altais is a triple! From Stella Doppie, the C star has a position angle of 22° and a separation value of 135.4 arc-seconds, magnitude 12.0. Curiously, the discovery date is the same as the AB pair: 1879. In the image, that's the beige-white star at the 11 o'clock position, a bit further than B, and a bit brighter. SkyTools 3 Pro has star GSC 04444-1492 at this location, (poor quality) mag 11.3.]

Slewed to HR 7361, a double.

double star HR 7361 in Draco

3:25. aka SAO 18287 or BUP 188. 5 seconds.

An intense blue-white primary. Again, you'd think this a multi-star system with all the nearby points of light. The companion is south, due south. White or grey. Nice field. Shot again at 3 seconds.

This time 'round, I was able to find the double HD 234577. Did I type it wrong before?  Shot blind. Whoa. Interesting stuff going on here... Shifted a bit and shot again.

double star HD 234577 in Draco

3:31. AKA SAO 30796, PPM 36426, and AG 217. 5 seconds.

There appear two doubles in the image. The right-hand pair, which are slightly tighter, is the target in question. The A star is the upper-left light tan point; to the south-west is the pale white slightly dimmer B star.

The east-most pair, with a slightly greater separation than HD 234577, is the pair HD 234579 (WDS VBS 27). Here the A star is bright with a very pale orange hue with the dim white B partner to the north-east.

Two for the price of one!

The blue-white star, HD 167103, to the west is unrelated.

Star hopped to Σ2332 using SkyTools as the target. Took a while. Near the neck. Shot blind. Got it! A delicate double.

double star STF 2332 in Draco

3:36. 5 seconds.

A is blue white. B, west, is very dim, grey. Orange?

Star hopped to another faint pair, STI 894. Shot blind again. Nailed it.

double star STI 894 in Draco

3:41. 5 seconds.

A is white, possibly pale blue. B, close, to the north-west, is white, a couple of notches dimmer.

From lessons learned during previous double star runs and considering the sketchy sky conditions, I grabbed data on the target multi-star system HD 172825 along the way. Returned to shoot a 5 second image. Moved west a bit. I wanted one very long exposure to get the field stars.

multi-star system HD 172825 in Draco with SLE 235 D

3:45. 30 seconds. Neat.

The primary star is the brightest in the field. It is white with subtle hints of blue. The B member is to the north-west or 2 o'clock position. Quite a bit dimmer than the lucida. A touch of pale orange. SkyTools shows B much dimmer but it is similar to C. The C element is to the west, slightly south, about double the AB separation. It is white. A fraction dimmer than B. Beyond B, about 5 times the distance, is a bright star. The software says this is D, specifically SLE 235 D. I went on this campaign as D is considered a neglected star in the Washington Double Star database.

Lots of data for reduction.

Reviewed my light frame times. Initially I viewed the EXIF data inside Backyard which was painfully slow. Went faster when I remembered the exposure value was in the filename. Programmed the dark frames run for all the exposures with 30 second delays. It would finish at 6 in the morning. Parked the 'scope. Monitored for cable wrap. Before installing the C14 cover, I dried off the corrector.

Fun. Overall, everything worked well. It took longer than I anticipated. Perhaps primarily due to taking more drift images and capturing more calibration stars. What I had forgotten is that targets near the North Celestial Pole have longer drift times.

The dew was incredible.

I'm thankful for the relatively clear skies.


Wikipedia links: gamma Draconis; omega Draconis; xi Draconis; delta Draconis.

No comments: