Bolton Astronomical Society

Comet observing using iTelescope
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Author:  rwilkinson [ Sun Dec 13, 2015 9:16 am ]
Post subject:  Comet observing using iTelescope

With the continuous frustration of the weather over the last couple of months, I decided to have a look at the remote-imaging service. This offers something quite different from the Bradford Robotic Telescope (which I've used many times in the past) - the ability to interactively control the telescope and take the image live.

This is a great boon for my comet observing, as I can choose a time when the comet is well-placed in the sky (and check the weather at the telescope site at this time) - but of course other comet-spotters around the world are all doing the same, so the telescopes can be quite busy at these times!

The other difference is the cost. The minimum BRT subscription was £3 per month for ten active requests on their scheduler (but with no control over when these images would be taken). For iTelescope, their minimum monthly subscription is 20 Australian Dollars, which works out at just under £10 at the current exchange-rate. This provides a montly credit of 20 "points" which are used to pay for the actual imaging time used. But as a new customer I was issued with an introductory 40 free points, so my £10 got me 60 points to play with.

I found that the service gives access to a dozen or so imaging systems at three sites in Spain, New Mexico and Australia, with a variety of different imaging sytems (which are all charged at different rates) so they cater for a wide range of interests across the time-zones.

Once I was registered (and even before paying any subscription) I was able to have a look around the web-site and see what the various telescopes were doing, and I soon came across one user (I think that it may have been Martin Mobberley?) taking this image of the two tails of Comet Catalina:
File comment: Comet Catalina on 9-Dec (resized from a single JPEG preview-image)
catalina_9dec.png [ 327.11 KiB | Viewed 6128 times ]
So that sold it for me, and I sent off my initial subscription!

Then I found that our new-telescope weather-curse even works remotely, as the conditions at the two Northen Hemisphere sites in Spain and New Mexico were poor over the next few nights. :roll:

But last night I finally got a chance to use the T18 telescope in Spain:
I soon found that the live-interactive mode of using this 'scope was a lot more satisfying than using the scheduler on the BRT: rather than submitting a request and then waiting for a subsequent email to tell me when my image was ready, I was actually in control of my chosen telescope in real-time! 8-)
In order to point at a comet (I'd chosen C/2013 X1 PanSTARRS), I first had to visit the Minor Planet Center website to get its latest ephemeris data, and then paste this into a box in T18's web-interface. Then I watched the command-console as it slewed toward my target, took a couple of preliminary images for plate-solving and focussing, and then started on my 3x 60-sec exposures.
When this process was complete, I received an email advice to download my image-data and that I'd been charged 6 points for this job (around £1 from my initial £10 fee).

I quickly read the three FITS files into IRIS for stacking and processing:
File comment: C/2013 X1 on 12-Dec, 3x 60-sec, resized x0.5 from original data
c2013x1_12dec.png [ 249.87 KiB | Viewed 6128 times ]
I was quite pleased with this first attempt, so next I'll be aiming for comets 67P and Catalina...

Author:  rwilkinson [ Tue Dec 15, 2015 9:27 am ]
Post subject:  Re: Comet observing using iTelescope

I managed to catch 67P/Churyumov-Gerasimenko in the early hours of this morning, using the 12.5" Planewave CDK telescope in Spain. But the comet is now so faint (below 13th magnitude) that even with a six-minute integrated exposure I needed a lot of streching of the image-data to see it:
File comment: Comet 67P on 15-Dec. 3x 2-min with 12.5" CDK at f/7.9.
67P_15dec.png [ 286.95 KiB | Viewed 6087 times ]

Author:  rwilkinson [ Sun Dec 20, 2015 12:41 pm ]
Post subject:  Re: Comet observing using iTelescope

Earlier in the week I used the iTelescope reservation system to book a slot on one of their New Mexico telescopes shortly before today's sunrise (= noon our time) when Comet Catalina was rising. Although they had poor weather earlier in the night, it cleared up just in time for me to capture my first image of this comet:
File comment: C/2013 US10 on 20-Dec. 3x 1-min using Takahashi Epsilon 250 at f/3.4 (rescaled x0.5 from original).
c2013us10_20dec.png [ 417.94 KiB | Viewed 6054 times ]

This used a Takahashi 10" Hyperbolic Flat-Field Astrograph, and shows the broad curved dust-tail and vestiges of the straight ion-tail.
I've got some more slots booked over the next few mornings on one of their wide-field instruments, so I'm hoping to catch more detail with that.

Author:  rwilkinson [ Tue Dec 29, 2015 11:45 am ]
Post subject:  Re: Comet observing using iTelescope

After a week of poor weather at the iTelescope site in New Mexico, I finally managed to get a clear slot on their Takahashi FSQ-ED 106mm f/5.0 Petzval Apochromat.
Unfortunately the Moon was very bright, which (although it qualifies for a 50% discount in imaging points) does limit the contrast, so I've switched to "negative" view to show the faint detail in the ion-tail:
File comment: Comet Catalina on 29-Dec. 3x 120-sec with 106mm APO at f/5 (rescaled x0.45 from original).
catalina_29dec.png [ 311.81 KiB | Viewed 6034 times ]

Author:  rwilkinson [ Sun Jan 03, 2016 11:22 am ]
Post subject:  Re: Comet observing using iTelescope

Here's my first comet image of 2016 - from iTelescope T14 in New Mexico (a Takahashi FSQ Fluorite Petzval Apochromat Astrograph):
File comment: Comet Catalina on 3-Jan. 3x 180-sec from 106mm at f/5 (re-scaled by 0.4x from original and cropped).
c2013us10_3jan.png [ 245.94 KiB | Viewed 6003 times ]
It's a little lacking in contrast, since it was taken with the Moon less than 60 degrees away.

Now the the trailing dust-tail is now more prominent than the forward-facing ion-tail.

Author:  rwilkinson [ Wed Feb 10, 2016 11:13 am ]
Post subject:  Wild thing!

Last night I managed to capture an image of comet 81P/Wild using one of the iTelescopes in New Mexico.
This comet is quite faint (currently around 12th magnitude) but is best-known as the one visited by the Stardust probe in 2004, which returned samples to Earth.
File comment: Comet 81P on 9-Feb. 3x 150-sec using Takahashi Epsilon 250mm at f/3.4
81p_9feb.png [ 267.83 KiB | Viewed 6031 times ]

These images were taken around 2:30am GMT (7:30pm in NM) when the comet was high in the sky (in Taurus), but I was trying the iTelescope's script facility, so that I didn't need to stay up to operate it live.
Their scripting is very simple - this is all I needed to request a series of 3x 150-sec images using the Clear filter with no binning:
; Comet plan for RossW
#count 3
#interval 150
#binning 1
#filter Clear
0081P 2016 07 20.3155 1.592167 0.538389 41.6978 136.1256 3.2390 20160731 7.0 6.0 81P/Wild
Here trackon selects tracking of a moving target and the line starting 0081P is 1-line ephemeris data (which I obtained from the Minor Planet Center's website) to enable the mount-controller to calculate the comet's exact position when it comes to take each image.

Author:  rwilkinson [ Tue Mar 01, 2016 9:34 am ]
Post subject:  An asteroid with a tail?

Comet 333P/LINEAR was originally classifed as asteroid 2007 VA85 in when it was discovered in 2007. But then a faint tail was observed on 8th January this year by Hidetaka Sato, so it's now a comet! It passed within 0.5 AU of Earth last month, reaching magnitude 13.

Last night I managed to catch it using a 10" reflector in New Mexico:
File comment: 333P on 1-Mar. Single 300-sec exposure using Takahashi Epsilon 250mm at f/3.4
333p_1mar.png [ 260.74 KiB | Viewed 5923 times ]
The other "faint fuzzy" on the right of the frame isn't another comet - it's a background galaxy!

This time I was putting the iTelescope's object-tracking facility to the test, by requesting a single 5-minute exposure of a fast-moving target. It certainly came up trumps, with the comet perfectly stationary in the middle of the frame whilst the background stars (and galaxy) are trailed.

Author:  rwilkinson [ Fri Aug 12, 2016 8:25 am ]
Post subject:  Re: Comet observing using iTelescope

It's not just Bolton - they've even been having cloudy nights at the iTelescope site in Mayhill, New Mexico recently!
So last night I had a go with one of their remote 'scopes in Nerpio (Spain) and caught my first glimpse of comet 53P, which was discovered in 1954 by Belgian astronomer George Van Biesbroeck and has a period of 12.5 years, so this is its fifth return since then.
File comment: Comet 53P on 12-Aug. 3x 200-sec with Takahashi TOA-150 apochromatic refractor at f/7.3. The camera is an SBIG STL-11000M, binned 2x2.
53p_12aug.png [ 230.45 KiB | Viewed 5374 times ]
The comet is around magnitude 13 at the monment, and the dazzlingly bright nearby star is only magnitude 6!

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