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Showing results for tags 'solar'.
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We have a fledgling Astronomical Society at my place of work and we're intending to have some telescopes available for colleagues to view the transit of Mercury in November. While the majority will use appropriate solar filters it would be good to have at least one set up for projection. However, we only have reflectors and Schmitt or Maksutov Cassegrain scopes among the members. I was considering buying a small refractor second hand to use for this but thought I'd ask for advice here first. Which is the best type of scope to use for projection? What do we need to look out for (overheating & fire risks for example)? What is the best umbrella to protect kit from the inevitable deluge on the 11th November? Thanks Mark
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Hello I have been away from this forum from possibly July - I never find a lot of time to do anything these days, same to be able to relax reading and interacting Astronomy forums. I asked here a few ideas about making a solar scope or modifying whatever I had and I was recommended to also see Solar Chat Forums and I did. Thanks to solarchatforums I have been able to do something decent and here is what I have done so far - very slowly! 1. I purchased a second hand PST and replaced its ITF with Maier one from the US and it finally had a clear image coming through + moved Etalon screw to third position - all the usual thing everybody does [after I researched it]! 2. used a new SCT screw-on short focuser [used once or twice on a LX200 R Classic] and using Teflon tape I screwed the PST Etalon to the focuser and purchased a 2" adaptor to fit on Etalon. 3. then used a Chinese 2" to 1.25 and modified the 2" side socket taking internal ring off and making 3x 120° threaded holes and 3x nylon thumb screws and used that as an adaptor to fit the original PST eyepiece holder - strangely enough at present this adaptor is also used as a tilter ... until I buy a proper camera tilter 4. then fit the above eyepiece holder into the SCT focuser with 2" to 1.252 adaptor in it and screwed the whole Gold PST tube with Etalon in it and made a BETTER PST - see image 5. I also initially tried a 2.2x DSLR camera Lens magnifier in front of PST and it decently works too - so PST will be fine for full solar disk mainly and without the 0.5 angstrom - not forcibly needed, I am probably around 0.7 as it is! 6. more importantly, I decided to make my own 90mm solar scope using the above bits and pieces. 7. with the help of Solar Chat Forums [great guys with a lot of knowledge, some are professional - i.e. they know the optics mathematical details - which helps] I purchased a cheap Bresser AR90/900 8. the ONLY usable thing there ... is the main tube, a nice and thick tube - the rest is ALL plastic!!! I dismounted all parts and saw tube shorter ... a bit too much ! - I could have saved ~6cm really as I went with original ideas, but forgot I was using a different telescope from my initial thoughts - silly me! So, I added a 6cm extension - no problems there to reach the 20cm inward needed for the PST Etalon which has ~20cm FL 9. initially I used a Tuna Fish 100g tin to adapt the SCT focuser onto my AR152 and fit Etalon inside the focuser to get near the 20cm needed- lets call it Quark unit - which it is really! It worked well, so I decided to add a second focuser to tune the Etalon ... getting back to AR90/900 ... 10. I was trying to avoid overspending, I could not afford to spend too much - then I remembered I had a unused AR102SX which in my mind I guessed ... the focuser should over AR90/900 and it did! It just fits perfectly - then drilled three holes for the holding screws et-voila' 11. I purchased a second hand 75mn Baader D-ERF and fit it INSIDE the AR90 tube at about 20cm inside from the front air-spaced doublet lenses, as there are the usual internal rings soldered in and just sit on it and I have about 70mm aperture - i.e 70mm width from the D-ERF for photons to get through. At that ~20cm distance from front lenses the beam is still very large - probably about 60-65mm - there is no heat in between - no need for air-escaping holes 12. when I have the time I will make a solar finder scope and fit it on the tube - not that is really needed - I usually use CDC to get there almost over The Sun [having an almost exact spot on the yard!] - then use my eye without eyepiece and look thourgh the PST eyepiece holder for solar shinging and centre the telescope over The Sun. Well, it works well after tuning Etalon focuser correctly and then focusing/tuning Etalon etc. - the usual. See some images - still learning imaging/processing and a lot more to learn about Solar ... a lot! I will probably need to get a Power-mate 2.5x when I can afford it! 1st mod - without the original black box - it works so much better - better focusing and sharper viewing too. This is the AR90/900 shorten tube with AR102SX focuser and adaptors to test it normally This is complete with the Quark Unit on the right side Since this image there have been some changing - do not use the revelation adaptor any more and added a 6cm 2" extension. Here are some images: -
[A few more photos are in the imgur album] Made this telescope for observing sunspots. The Sun gets projected onto a piece of paper after bouncing from 3 mirrors inside the frame. It's compact, light, takes only a few seconds to point at the Sun, and sketching sunspots is as easy as circling the spots on a piece of paper. It can even project the Moon: The design is inspired by a commerically available telescope, but I’ve done all the designing myself, just for the fun of it. Sunspotter is full of little details that make it interesting. How do you fix the eyepiece in the exact place where it needs to be? How do you keep the lens in place and perfectly aligned? Building the telescope was a lot of fun, I’ve learned to use a jigsaw, X-Carve and a 3D printer. The plan is to use it to complete the Astroleague Sunspotter Observing Program, but unfortunately I completed it at the minimum of a Sun cycle, and won’t see any sunspots until next year. Telescope parameters: Magnification: 75x Size: 41cm x 41cm x 15cm Weight: 1kg Design: Keplerian Projection size: 75mm Materials needed: Lens: Ø52mm f=750mm achromatic doublet Mirrors: 1, 2, 3 Eyepiece: Baader 10mm ortho 1.5m² of 10mm plywood Wooden glue 5m of PLA filament 12 nails Compressed air Isopropyl alcohol Tools I used: Jigsaw with a 30° bevel capacity X-Carve 1000 3D printer A laser pointer Clamp Learned modelling basics in: LibreCAD Easel TinkerCAD Fusion 360 Part 1: Choosing the lens The idea of a sunspotter is that the light goes through the lens, travels inside the telescope, bouncing from 3 mirrors, enters an eyepiece and the image gets projected on one of its sides. The distance the light travels before entering an eyepiece is the focal length and it determines the size of the telescope. I chose a Ø52mm f=750mm achromatic double. Observing the Sun doesn’t require a large aperture, 50mm is more than enough. I wanted a high magnification and went for the longest focal length I could find, which was 750mm. Achromatic doublet design is what people use in refractors. If it is good enough for a refractor, it’s definitely good enough for my project. With the focal length chosen I could design the wooden parts. A drawing showed that the frame needed to have sides 30cm long, but I wasn’t sure about the placement of the mirrors and went for 31cm sides, planning to shorten the light path as needed by adjusting mirror positions. This is the LibreCAD drawing of the layout of parts on a piece of plywood: Part 2: Building the base Having a drawing of the base in LibreCAD, I printed the drawing 1:1 scale on multiple A4 sheets of paper and glued them together. I transferred the drawing to a piece of cardboard and cut it out. Applied this cardboard template to the sheet of plywood, and cut out two parts with a jigsaw.. I’m not an experienced user of jigsaw, and couldn’t manage to cut half-circles accurately enough. Even worse was that the two parts were very different. I didn’t want the frame to randomly tilt left or right when adjusting its altitude, and had to spend a lot of time with sandpaper to make the halves as similar as I could. Glued the two large parts with three small parts in the middle. Additionally nailed the parts and the base was ready. Part 3: Frame The frame is simply a triangle made of three pieces, with short sides cut at a 30° angle. Most jigsaws can cut at 45°, but not at 30°. Had to buy a new jigsaw with a 30° bevel capacity. Cut out three sides, cut short sides at a 30° angle, but didn’t put them together just yet. The lens needs to be perfectly aligned with the Sun-facing part of the frame, otherwise the Sun projection isn't circular but elongated. My solution was to carve a hole with a little step as shown on the image. The inner hole is Ø46.5mm, the outer hole is Ø50.8mm. The outer hole is the exact size to let the lens fit, but with a little bit of friction. Had to carve several holes to find the minimal size the lens could fit in. The step is just large enough to have enough surface for the glue to keep the lens in place, I didn't want to reduce the aperture too much. I used an X-Carve for carving and Easel for modelling. With all 3 sides ready, I could assemble the frame. It appeared that my 30° angle cuts were not very precise, but after some sandpapering the sides started fitting together alright. Glued the parts together and left them to dry for a day. To apply some pressure on the joints, I wound several twine loops around the frame really tight, made sure all sides fitted well together and left it to dry like that for a day. Part 4: Mirrors When selecting mirrors I was looking for the smallest mirror that fit the cone of light. Small mirrors are a lot easier to place, and they let me better control the length of the light path. I considered using elliptic mirrors, but they were bulky and really hard to place. All mirrors are first surface mirrors, otherwise planning their locations would be a lot more confusing. This was my original plan of placing the mirrors: As you can see, all the angles and distances were carefully measured, and I wanted to simply make mirror holders of those exact dimensions. This was clearly a bad idea. I 3d-printed some parts like this: And only later I realized that the frame angles are not exactly 60°, and that there are drops of glue along the edges that don’t let me fit the pieces deep enough in the joint between the sides. I cut angles from all the mirror holders: After I put the first mirror in place I realized the angles are all wrong, and that I needed to re-do the holder. Separating the mirror from the holder was a huge pain, which resulted in an accident. The mirror fell off the desk and got damaged. Luckily, only the back side got damaged, the front side was still working: The final designs of mirror holders looks like this: The holes in the front surface let me apply pressure on the back of the mirror if I ever want to separate it from the holder. The recesses collect the excess glue to avoid mirror skewing when gluing them. All other holes are simply to save the filament. Part 5: Placing mirrors What I learned is that you can’t plan positions of several pieces with high precision and just hope that it all comes together. I needed a feedback about the precision of mirror positions. I used a laser pointer to verify mirror positions at each step. In the picture you can see that the laser is firmly set in a hole in another piece of wood, with layers of isolation tape on the tip of the laser pointer to make it stable. A clamp holds the piece of wood in place, ensuring that the laser ray goes in the same direction as a solar ray would. A crosshair of black thread at the center of the lens ensures the laser goes exactly through the center of the lens. When placing each mirror, I marked the spot where I expected the laser to end up. While gluing the mirror holder to the frame, I kept the laser as close to that spot as possible. If for some reason, the laser couldn’t hit the expected spot, I did my best with placing the mirror, and recalculated locations of the following mirrors. I saw the first sunspots after placing all the mirrors and simply holding an eyepiece in hand. Part 6: Eyepiece holder I tried eyepieces of different focal length and liked the picture I got with a 10mm eyepiece the most. An eyepiece needs to be in a very exact spot to produce a sharp image. At this point it was obvious that my frame doesn’t match the model, and that I didn’t even know what exactly was wrong with the frame. I didn’t want to rely on the model and moved forward with trial-and-error. I printed several parts to hold the eyepiece, with different eyepiece locations: The part in the photo was a total disaster. It needed quite a lot of filament, at the same didn’t have enough surface area to be glued to the frame, and not enough surface area to hold the eyepiece firmly. The next iteration was a lot better: This part has a lot more surface area, and needs less filament to be printed. I intentionally printed the hole for the eyepiece too small, and had to sandpaper it a little bit, to make the eyepiece stay firmly fixed. Adjusting the focus is done by sliding the eyepiece up and down until the Sun becomes a circle with well defined borders. Part 7: Dust All optical parts should be kept clean. Dust on the mirrors and the lens will make the image darker. Dust on the eyepiece will show up as artifacts on the projected image. Unlike sunspots, the artifacts will not move with the Sun. To clean the eyepiece I used compressed air. To clean the mirrors I used isopropyl alcohol. Part 8: Fire safety Don’t leave devices with magnifying lenses lying around. Once the Sun happened to be in such a spot that its light went right through the lens, burning through the cap of the eyepiece. Luckily, nobody was hurt and no other damage was done. Part 9: Future work Build quality of the base is very poor. The frame tilts sideways when adjusting its altitude despite all my efforts. I’d like to build a new base, but leave all the work to the machines. I already have a model for an X-Carve to make both base parts, compatible with my current frame: A notch along the edge of the half-circle should eliminate the tilt. The precision of the machining should make the base very stable. Maybe next year, when sunspots become a common daily sight, I’ll get to this project. Thank you for reading this far! I hope you enjoyed it.
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I've just bought a Daystar Solar Scout 60mm DS for H-alpha imaging of the Sun. I am now looking for a suitable camera to use with it. I know I could use my DSLR, but for H-alpha that is not going to give best results, so am looking for a dedicated monochrome imaging camera. I have identified the ZWO ASI178MM as a possibility that fits my budget and has a large enough (I think) sensor to image the entire Solar disc if I use a 0.5 focal reducer which will give me a total focal length of 465 mm. Does anyone have any experience of this camera in this application, or know if it will be suitable? I know it does not have an IR blocking filter, which I understand is an advantage for H-alpha. The spec is available here: https://www.rothervalleyoptics.co.uk/zwo-asi178mm-usb-30-monochrome-cmos-camera.html Thanks Mandy
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One of the best cameras for Ha solar. With a 1/2" chip and large pixels, I used to fit the entire disc with lunt 35. I can still do a full disk with a quark using my TS 60ED and a reducer on the camera nose. This camera does not suffer from Newton's rings so saves a lot of time which is otherwise wasted in setting up a tilt adjuster. Boxed with the cable, probably i have the disc as well, but not sure where in my astro dump it is. Software is available from the website though. £180+pp-
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Dear all, the prominences of the previous days on limb of the sun now are visible as filaments on the solar disc itself. Lacking amazing prominences on the limb, I hsve been concentrating on sketching the filaments this time. Compared with my previous sketches they moved from the right towards the middle. Note that my sketches are usually left-right-flipped due to the telescope's mirror. So here's the result: Telescope: Lunt LS 50 THa B600 PT Eyepiece: Celestron X-cel 10mm Date & Time: June 7th, 2019 / 1000-1030 CEST Location: home terrace, Dusseldorf region, Germany Technique: reddish and black Koh-i-Noor soft pastels and pastel pens on light-grey Hahnemühle Ingres mould-made pastel paper Size: 24x31cm Clear and sunny skies! Achim
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The Sun today - 07 May 2019 0130UT (1130 AEST) Lunt LS60THa single frame exposures with an ASI 1600MM AR2740 with AR2741 just coming around the limb This last one using a Televue 2.5x Powermate cheers Dave
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Hi I took my first Solar avi's today with a PST and QHY5-II. They were not that good due to intermittent cloud, but I managed a few runs of 1000 to 2000 frames. I have been trying to process them but both Registax and AS2 are falling over during processing. AS2 runs through quite quickly but just hangs at the MAP Recombination stage. The Stack button rehighlights and the system is idle but no file is produced. Registax takes for ever but hangs after the Limit stage. I am running Windows 7 on an i3 laptop. Any ideas? Is it something I am doing or could it be a quality issue with the video. Thanks Barry -
While the solar observing specs are on back-order I decided to have a go at making some binocular solar film filters, so ordered an A4 sheet of the Baader solar film and downloaded the Baader instructions. While the translation may have lost out on one or two small things it was very easy to follow the guide to build my own objective filters using the film and some white card. The view through them is better than I had imagined, there is some granularity visible (like a gradient around the edges of the sun giving it a spherical appearance) and right now I could see three large areas of sunspot activity. The colour is white as advertised, with shades of grey and black. I could just make out the branches of a tree that were close to the sun, probably just their shadow I could see as they blocked some of the sun's energy. As per the instructions, I held both filters up to the bright daylight to check for any pin [removed word] holes before using them with the binoculars. They are a snug fit for sure, no chance of them coming off once they are firmly pushed on. [can't believe the profanity filter removed a word meaning to make a small hole with a pin!] These fit my 8x42 Bushnells, I'm sure a larger pair of binoculars would show an even better view. I may attempt to make one for my 102 refractor with the remaining portion of the A4 sheet. All I need now is a safe piece of tupperware to carefully store these in. Would be interested to see what others have made with solar film.
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Here's an attempt from today. I was blessed with clear skies almost all day so tried my hand. This is using a Skywatcher st80 80mm f/4.5 with omegon t2F-m48M adapter and then the quark screwed down tight to the end. I am try8ing to get to the level of detail seen here in others. These images are 20 secs between 70 and 100 fps using firecapture and a ZWL120 mono. Focusing is as good as I can make it by hand. There's still a few dust spots left but other than that, any tips? Active region Large prominence Mike
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Managed to grab some H Alpha and Ca-K data whilst out this morning. Pretty windy at times so quite (pleasantly) surprised how well these have come out. Proms in Ha & Ca-K 6 Pane Ca-K full disk AR12490 @ 2000mm focal length.
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Hi guys, I wanted to share with you a detail of an AR I captured with my modest setup some days ago. Nothing fancy or special, but it is the first time I have managed to get such level of detail, so I'm happy with it. Setup SW 114/900 Newton on EQ2, motor focusing Prestigio PWC2 webcam, IR-cut filter, Baader Astrosolar, Hyperion Zoom Barlow 2.25x Enjoy.
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Hi all Really really struggled to get this working in photoshop. I think I've screwed up the exposure on the prom capture so the disc ended up being a fair size larger than the surface detail which was always going to give me a bit of a halo around the image. Hope its not too bad but comments and advice are always welcome Taken with the Coronado Solarmax SS60 and PGR Grasshopper today, 700 frames proms, 1000 surface. Not much happening today when I took this which is a shame because I've just seen some cracking pictures of looping proms from yesterday! Clear skies all Cheers Will
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Perhaps the most interesting and curious archaeological object related to astronomy is the Antikythera mechanism. It was discovered a little over 100 years ago in 2nd century B.C. shipwreck near the Greek island of Antikythera and is now in the National Archaeological Museum in Athens. After more than 2,000 years on the seabed, it is obviously in poor condition and badly damaged. However a variety of complex imaging techniques have begun to unravel its secrets. It is a very sophisticated mechanical "computer" to calculate the cycles of the Solar System. For an overview, see: https://en.wikipedia.org/wiki/Antikythera_mechanism And for more detail: http://www.antikythera-mechanism.gr/ For me, the most fascinating aspect of this unique surviving object is that presumably it was not unique in its day. It reveals a level of scientific knowledge and technology which may have been available at least in the eastern Mediterranean.
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Hi, Has anyone noticed any spherical aberration or off axis aberrations (field curvature, astigmatism & coma) in an achromat in h-alpha? Or a better overall image quality in any way (clarity, resolution, sharpness, contrast, brightness etc) using an APO or ED over an achromat? Thanks
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I've made a pinhole projector out of a carpet roll tube which is about 8' long. I made a small window in the bottom end, added the white platform for the projection in the bottom, and covered the top with a small patch of tin foil with a hole in it. I have tried pointing it at the sun so that the shadow is at its smallest but I cannot get a projection of the sun on the white plastic surface I put in the bottom, what am I doing wrong? The only thing I can think of is that the projection is too dim and cannot be seen, if that is the case then what is the answer? I'm thinking maybe I need more shade around the viewing window, or maybe I need to use paper instead of white plastic to project onto (can't see why though - white is white). Any pinhole projector experts here who can advise please?
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Here's a 10 frame animation. 1 frame per minute. It shows the movement of this large prominence over a very short time frame. A full frame shot to show the relative size of this huge prominence. And another shot with a black dot that shows the relative size of the Earth. Tech Details: Lunt 80mm Ha telescope, ZWO ASI1600mm cooled camera. Processed in AutoStakkert!2 and ImPPG, colorized and layered in PhotoshopCC.
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I've been using a Quark chromosphere now since May and just wanted to share what an absolute delight this piece of equipment is (albeit I never seem to have enough cloud free sky to get it right on band). I had been using a ST80 but felt this was lacking and not a great match for the Quark in terms of focal length. I've since moved to a 120mm refractor and hope the images show how capable the Quark is.
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My first attempt at photographing a Transit and I decided to try for the 2nd and 3rd Contacts, but of course as those in the UK will know, the final phase of the Mercury Transit was clouded out. So, here's my attempt to capture "2nd Contact" using a Canon 600D (unmodded) at eyepiece projection with a Baader Hyperion 17mm, Baader Solar Continuum filter, Lunt Herschel Wedge and a Skywatcher ED80 DS Pro on a HEQ5:
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Apologies if the sun vanishes for a while - my new Lunt arrived and is now unboxed and ready for use - hoping for some sun this afternoon. I got the skytee 2 so I can have the TV85 alongside with the Baader wedge. It'll be interesting to compare viewing through both scopes. -
Hope this is the right place for my post So with the 9th of May approaching I want to try the following add a solar filter to my Skywatcher Explorer 250 Add a camera instead of the eyepiece and then via the laptop project onto a flat screen in the club house so members of the public can see it in total saftey So a few questions 1 - so the skywatcher cover has the removable 2 inch cap and reading online it seems for the sun this is the best approach, leave the cover on and have a filter over the smaller hole - can I buy a premade cover for the 2 inch hole 2 - Cameras - I have a choice of QHY5, QHY5 II or an oldder Philips Webcam spc900nc - any thought on which would be the best to use ? 3 - What software would be most appropriate for this project Thanks in advance John B
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After opinions please ... I have a C8 that I use for planetary imaging / visual and a 250 px Dob for DSO visual . I haven't touched the Dob for what seems like forever and keep using the C8 more and more . I have about £300 Christmas / birthday money and keep thinking about selling the Dob to maybe fund something like a Lunt 35 or 60 second hand to throw on the AVX ? Have any of you been through this process and were you happy ? Cheers for reading
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Here's my take on today's white light disc. Flaring AR11748 is in u/left of disc...
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Here's my white light result from May 26th. Looks like another small spot rotating into view close to the eastern limb.
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The prominence display on the western limb continues... Pete
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