Search Results for 'espin telescope'

[Nick James]

One of the advantages of an SCT is that you can move the focus in and out by a lot through small shifts of the primary mirror. You should be able to solve your problem by releasing the mirror lock and turning the focus knob. Given that this is an old C14 any mirror lock will have been added afterwards so you will need to work out how to release it.

Anticlockwise rotation of the focus knob (as seen from the back) moves the focal point away from the telescope (at least in all the SCTs I have) but you can check how the focal plane is moving by looking at your projected moon image. It is a characteristic of this method of focussing that the effective focal length changes a bit as you shift the primary back and forth. Don’t worry about the mirror falling off the central baffle. The focus knob will stop moving at the end of its travel.

Once you’ve got a decent back focus distance you can lock the mirror again and use your Moonlite focusser for fine adjustments.

[Mike Harlow]

There are a couple of other options for solar viewing.
My favourite is a long focus mirror fed by a driven flat mirror. My version had a 4 inch mirror of 47 feet focal length which gave a solar image 5 inches across…i.e. bigger than the mirror! So although the sun if focussed the surface brightness is less than that of direct sunlight. Sorry I don’t have any images but there was a short piece in Astronomy Now, November 2008 page 75. Not an original idea by me…Hale made a 100 foot solar telescope which was described in detail in volume 1 of the Amateur Telescope Making books.
The other option is to have a heliostat feeding light through a single lens (no need to be achromatic) with the image viewed through an H alpha filter as usual. A nice example is shown in Sky & Telescope, August 1980, page 162. The 24 foot focal length lens gives very detailed views of prominences etc.
These set-ups are obviously much more involved than conventional methods but would make nice projects for astronomy clubs. They have the advantage of having all the optical elements on show so people can see how they work.
Mike.

[Jeremy Shears]

I would like to use an 80mm refractor for public outreach for white light solar observation.

The telescope will track the Sun, potentially for several hours. In that time hundreds of people would observe the Sun. This includes large groups of school children. It will be supervised, of course. Though excited 9 year olds are quite lively!

Note that my primary concern is safety. I am not worried about small differences in the quality of the views provided.

I have posed the question to the Solar WhatsApp group which method is safest in this use situation. Among the helpful replies, three options have arisen:

1. Using a full aperture Baader film filter. This was my initial plan. But I am concerned about it being knocked off or pinholes appearing (the device would fit over the dew cap, held in place by screws, but not rigidly attached – taping in place each day is probably not conducive to long term use).

2. Using a Herschel wedge. This strikes me as a safer option and better from an engineering perspective as the wedge can be firmly attached to the telescope. My residual concern is that after several hours, the housing might get hot, presenting a burn hazard or be damaged in some way. Does anyone know whether these concerns are borne out in reality?

3. Using a projection box. This is probably safest of all, though my experience is that the image is often too dim for casual observers. It also doesn’t give the experience of observing THROUGH a telescope (similarly, Smart Scopes or cameras on the back of the telescope are not options under consideration).

Any views based on experience? Any risks assessments that can be shared?

[Mr Giovanni Di Giovanni]

Your notes are beautiful. They remind me of my enthusiasm and excitement when I built my first telescope half a century ago. A Newtonian D200 f1400, worked on in my garage, the mount entirely homemade using mechanisms from old cars being scrapped and gears from a rotisserie, with manual tracking. The photometer was a photodiode at the focus of a microscope used to examine photographic plates. Reading your notes, memories emerge unchallenged and presumptuous.
Happy New Year 2026 (and following) to all of you.

[Steve Knight]

Are occasional mobile smart telescope users allowed to participate? 152 nights (41.6%), best month May (24), worst February (4).

[Dawson]

I am still sorting through some pamphlets and paperwork from Alan Heath’s house. I found this fascinating photo from about 1961 of a clock drive he had built and an 8×50 Elbow Telescope… I have to confess I’d not heard of an Elbow Telescope before.

I just thought this may be something other may be interested to see, and to save the image for prosperity.

James Dawson
Nottingham

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[Tim Haymes]

Hi William. I was pleased to read your helpful comments. Thanks.
One of my follow up remarks on progress was also lost. The dome connected fine with the Pulsar ASCOM Driver and i could use the buttons to move the dome, but EQMOD would not connect to NINA, although it was connected with SkyMapPro and SharpCap. Thus the telescope and Dome were not talking.

Im pleased to report a solution:
At a recent meeting of my local AS: Abingdon, a software engineer suggested it was likely down to “permissions”. Both SharpCap and SkyMapPro were run as Administrator (on my system), NINA was not. Ive now corrected this and hey-presto! the dome can now follow the telescope.

Im still in ASCOM 6 but NINA warns.

[Nick Quinn]

This ATel has a high-resolution image from December 6th taken with the 8.1 metre Gemini North telescope – a 3 second exposure!

[William Bristow]

I’ll have another attempt at answering, for some reason my replies to this and other topics in recent months just disappear after pressing the submit button.

Tim,

The ‘Dome Following’ button is only active when both the Mount and the Dome are simultaneously connected in N.I.N.A and you have correctly configured the dome and telescope/mount geometry in N.I.N.A’s Options > Dome tab.

Depending on the U.I. colour scheme the ‘Dome Following’ button changes from a dark shade of grey to a lighter shade of grey when the mount and dome are both connected, it’s easier to see when the U.I. Light display mode is selected, you just click the ‘OFF’ button and it will change it’s wording to show ‘ON’.

If you haven’t yet configured, or have misconfigured the dome and mount/telescope options, then an error notification will appear when you click the ‘Dome Following’ button and the dome will be automatically disconnected in N.I.N.A.

William.

[Robin Leadbeater]

The Mauve space telescope with a mission to study stars in the UV has been launched
https://bssl.space/blue-skies-space-launches-satellite-to-study-the-hidden-lives-of-stars/

With the falling cost of technology and launches I wonder when we will see amateur space telescopes ?

[Nick James]

The weather at the Alnitak telescope in Spain has not been too good the last few nights but I did get an image of the comet from Chelmsford yesterday morning. The comet is now moving away from the Earth so the physical scale is getting smaller but fragments are still visible. I’ll be preparing a report for the February Journal so many thanks to everyone who has submitted images.

The latest images in the section archive are here:

https://britastro.org/cometobs/2025k1/thumbnails.html

Most of these are north up so you can see how the tail has rotated rapidly over the past few weeks as our viewing angle has changed.

[Dr Paul Leyland]

Anyone who would like to image and, especially, to measure a variable star in an external galaxy should pay attention to this announcement made only a few hours ago. If you follow the link you will discover that the discovery was made with a 23cm aperture telescope, something well within the range of equipment used by many BAA members.

Dear colleagues,

The 2025 eruption has been discovered. Please try to increase your observing cadence to monitor the light curve.
The nova was discovered on Nov. 30.3634 with a magnitude of 18.7 by Koichi Itagaki as reported on TOCP page below:

http://www.cbat.eps.harvard.edu/unconf/followups/J00452879+4154101.html

Best regards,
Hiroyuki Naito, Nayoro Observatory

M31N 2008-12a erupts annually and has by far the shortest period known for a recurrent nova. By comparison T CrB, for which everyone seems to be waiting, has a period at least 80 times longer.

Paul

• This topic was modified 10 months, 3 weeks ago by Dr Paul Leyland.

[Mr Ian David Sharp]

Your chance to own this classic and beautiful telescope. I bought it in 2021 and it has barely been used and has been stored indoors for most of the time. The Takahashi 1.01x field flattener is also included.

You can see my setup here: http://www.astro-sharp.com/2021/09/29/my-new-deep-sky-imaging-setup/

Full, original packaging included.

I used it with a Pegasus Astro Motor Focus V2 and still have this – ready to be fitted. Let me know if this is additionally wanted.

I’m asking £2750.

[Nick James]

Courtesy of the BAA/Comet Chasers group I have processed some data obtained earlier today from the 2.0-m f/5.2 RC Foulkes Telescope North (F65). This has an image scale of 0.27″/pix. This image is resampled by a factor of 2 and is 2.3 arcmin square. It is a stack of 3x10s images taken at half the comet’s offset rate.

It shows a separate, faint apparent fragment just ahead of C and an elongated bright area behind A. It also confirms the demise of fragment B.

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[Nick James]

This morning’s (Nov 22.22) image from the Alnitak telescope in Spain shows that component B has become very diffuse and it looks as if it is not long for this world. The astrometric residuals for B are now large and this reflects the fact that it doesn’t have a definite centroid any more.

The astrometric residuals for component A are generally small and they fit the previous orbit well, so we presume that this is the original nucleus, but the astrometry from this morning shows significant residuals. This component has also brightened significantly over the past few mornings. This may be a sign of further fragmentation so please keep observing this comet as frequently as possible.

This is why comets are so much fun. You never quite know what to expect when you observe them!

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[Nick James]

This comet was reported to have fragmented on or about November 4 (ATEL 17482, 17487, 17488). There are several fragments but the two brightest are the main component and fragment B. Recent images are in the archive here:

https://britastro.org/cometobs/2025k1/thumbnails.html

Attached is a plot of the all the astrometry that I have. The recent astrometry consists of my measures using the Alnitak telescope in Spain (I79) on Nov 12 and 13 and Denis Buczynski’s measures using his telescope in Tarbatness (I81) on Nov 14. The plot shows the residuals for the main component as filled circles and the residuals for component B as open triangles. These residuals are from the fitted orbit using all the available astrometry (from the MPC) prior to November 4.

The main component shows a large positive RA residual which is matched by a similarly large negative residual for fragment B. A simple-minded interpretation of this would be that both components have a similar mass but fragment B is much fainter so that doesn’t seem likely.

If anyone has any recent (post November 11) astrometry of this comet please forward it to me and the MPC. Astrometry of the main fragment (C/2025 K1-B) would also be very useful. It is now well separated from the main component.

• This topic was modified 11 months, 1 week ago by Nick James.

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[Nic Spencer]

I have a Double Stacked Coronado Personal Solar Telescope for sale for £1100 or best offer. The well-matched etalons allow safe observation of the features of our sun in h alpha. If you’re a beginner,then I can offer you as much support as you need to observe and/or image with it.
For more information please contact Nic Spencer at nicspencer1@gmail.com I live in York, North Yorkshire.

[David Swan]

Pleased to snap C/2025 R2 this evening, when it was low in the SW. Put the telescope on Phi Oph at about 7.15pm and waited for sky to darken.
12x10s, midpoint 2025/10/11 18:45 UT
MiniCat51 – Image Centre RA 16h 30m 48.5s, Dec -16° 40′ 04.6″ – Pos Angle +208° 40.5′- FL 173.6 mm, 8.94″/Pixel

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[Martin Reeve]

I started the project in February of this year.
The telescope was my own design. I wanted a telescope for visual deep sky observing, so decided on a low f ratio and it had to be able to break down (by removing the truss-poles) to fit in the back of an average car.
I finished it in May and I’m pleased with the results. It’s stable, solid and the axis’ move smoothly.
The mirror took a bit longer.
5 months longer. One turned edge, two pitch-laps and three parabolising attempts later and I have what Terry Pearce of Vacuum Coatings described as an “excellent parabola”. Coming from a man of his knowledge and experience, that’s high praise indeed. In fact I measured the mirror at better than 1/10 P-V wavefront which Terry thought to be somewhere near.

It was a very enjoyable project. The most challenging aspect being mirror polishing and parabolising. I learnt a lot during the process and I’m already thinking about a small table-top dobsonian as another project.

I’d like to thank Denis Buczynski for his generous donation of the mirror blank and tool. Also Terry Pearce for his evaluation of my mirror at his ATM club, and excellent aluminising service, and Mike the Ebay seller who supplied the extra Cerium Oxide I needed and some very helpful advice.
Also thanks to David Arditti for the telescope making article in the 2024 August BAA journal for giving me the initial spark.

I haven’t had much luck with the skies lately, but I did get some lovely views of Saturn and the Moon in the last couple of nights.
I’m looking forward to putting it to good use during galaxy season.

Clear skies to all.

[Dr Paul Leyland]

Robin Leadbeater wrote:

<p class=”wp-dark-mode-bg-image”>A test would be to take images with the telescope rotated to different angles (but with the camera orientated the same relative to the horizon). If it is atmospheric refraction the red and blue areas will always be top and bottom relative to the horizon. If it is the telescope, they will move to different angles relative to the horizon

<p class=”wp-dark-mode-bg-image”>Cheers<br class=”wp-dark-mode-bg-image”>
Robin

Good point. I wish I had thought of that.