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Showing content with the highest reputation since 27/05/20 in all areas

  1. 23 points
    Taken over 3 nights as it was late rising over the house tops with little Astro darkness. Atik460EX and Samyang 135mm F2 lens @ F2.8HEQ5Ha 4 x 900Ha 15 x 600Oiii 10 x 300 binnedSii 12 x 300x2RGB stars 6 x 150 (eachTotal of 6 hours 5mins
  2. 23 points
    Completely ridiculous, clear skies every night, keep giggling like a kid with candy. Tuesday night 26th May. Did a load of homework on Stellarium and the star charts (I need both) and I do the usual optimist route. Time will tell. Set up the EQ5 with the 150 pds in bright sunlight. Not a single cloud and I grab the bins and the dogs and walk to the top of the lane to observe Venus and hopefully for the second time Mercury. Venus against the bright sundown ‘amazing’ quarter illuminated disk, like a distant mimic of the moon. I had to wait till 23:00hrs till it was dark enough to do any EP work. Sat back in the chair watching space junk tumble and flash across the sky! Would make an amazing AP trail. First up M13 just to test alignment. I have spent a lot f time on this recently so for me no need to dwell. Next Glob M 92, I prefer this in the EP to M13. Appears to have a tighter brighter core. It’s outer area seems to do a similar thing to Andromeda. Focus on the core but there seems to be much more. Heading over to NGC 6210 Turtle Nebula still in Hercules. Should be beyond my mag limit of tenish. Surface brightness made me say “why not”. First look, three stars, nothing else. Hooded up and the lower star is not sharp. More an out of focus blob, with a light blue green colour. Soooo small. First for me! Then a meteor shoots through the fov, amazing. Into Draco. NGC 5985/ 5981/5982 Draco’s Trio. Absolutely nothing! I have been doing so well but the brightest at mag 12 was going to be a stretch. M102. I would normally talk about this, but I noticed in the charts a nearby edge on galaxy NGC 5907. Gob smacked, better than 102, I have that ear marked for an AP session. Into Lyra. Quite low on my horizon for the time, just after midnight. Would be rude note to look at the Ring Nebula M57. Just want to say that when I do EP sessions I use the voice recorder on my phone. Listening back to record my notes I have the following... Who ever first saw that through a scope must have wondered how there is a polo mint in space. Completely forgot NGC 6543 The Cats Eye Nebula so back to Draco. Nice Crisp Blue Ball. Larger than Turtle. Over to Cygnus. So many open clusters! I am sorry to say that I am underwhelmed by OC’s. Getting close to bed time now so a chance at the Eastern Veil. NO CHANCE, way to low to my horizon. If I could only stay out all night. Now to unfinished business. The Blinking Planetary! For a planetary a bit bigger than I was expecting. White in colour, but could not discern any blinking. Must look into that. Ended with a chancers look at M83 in Hydra. I am 103/110 of Messier’s list. Now 104/110. Very low to the horizon but no averted vision needed. Wishing you all clear skies and the opportunity that I have just had. Marvin
  3. 22 points
    Hi all, I can't believe i even got an image given the conditions for rgb imaging. No astro dark, quite a low target and an average 70% moon over the two nights. I just recently set about collimating the Epsilon and i think the increased sharpness from decent collimation shows. It's still off in the upper corners so more tweaking required. I wonder is it tilt i'm looking at or spacing. So this is 5 hrs gathered over the last two nights 100*180 second subs with the Asi2600mc through a Takahashi Epsilon 130 Mounted on an AZEQ6 Sequence generator pro for the image acquisition. Processed in APP, PI, and PS Richard. .png .jpg
  4. 20 points
    Having a good run of clear nights lately, and I am having a ball with this excellent Samyang lens and getting images I have done before but with a wider FOV. Taken over the last couple of nights (whilst chatting on Anybody Playing Tonight thread). Ha 21 x 600 Oiii 4 x 450secs binned + 7 x 300secs binned Sii 10 x 300 secs binned + 4 x 450secs binned RGB 5 x 150 each (for stars) Samyang 135mm F2 Stopped down to F2.8 Atik460EX and Baader filters on HEQ5 Little Rosette at bottom of image Total Imaging time 6 hours 32.5 minutes
  5. 19 points
    This is a reprocess of old data using a star reduction technique I hadn't encountered at the time I did the original. Obviously we're in the thick of the Milky Way here and holding down the stars to let the nebulae do the talking is tricky. The image is HaLRGB from the Tak FSQ106N and full frame Atik 11000 (still my favourite camera...) Both nebulae were enhanced by applying higher resolution data from the TEC140. All I did was remove the stars entirely from a copy and then replace them with the originals at only partial opacity in blend mode lighten. Very easy indeed and, for the first time, I'm happy with this one. Mount, as ever, was a Mesu 200. Olly
  6. 18 points
    Wanted to get double this data but ran out of clear skies: Taken over 2 nights March 2020 from Bortle 8Samyang 135mm F2 lens stopped down to F2.8Atik460EX and Baader filtersHEQ5Ha 2 x 600secs + 6 x 900secsOiii 6 x 300secs binned + 3 x 600 unbinnedRGB 3 x 150 (each)Total imaging time 2hours 55mins (almost 3 hours)
  7. 17 points
    I've been less active lately in this hobby, but I've a few images done, others waiting in the pipeline to be processed. This is a "crowded" area of our Milky Way galaxy, visible all summer from the northern hemisphere. The Cygnus constellation is home of many named and nameless nebulae. Starting from the left (North), below the brightest star, Deneb, the Pelican and the North America Nebulae are very popular; going to right, just below the brightest star close to the center of the image, Sadr, lies the Gamma Cygni Nebula. A bit towards the top-right there's the Crescent Nebula and going forward top-right, there's the Tulip Nebula. Finally, at the bottom-right corner, the Veil Nebula, a super nova remnant. All these are surrounded by shiny gaseous filaments or dusty patches blocking the light. I started this during the pandemic lockdown. All of the data was captured from my hometown from a balcony brightly lit by a sodium street lamp, but the narrowband filters did their job well, blocking successfully the sodium emission. A total of 23 hours is made of 2x3 panels composed in a larger mosaic, each panel consisting in about 1h of exposure for the red Hydrogen and 3h of exposure for the cyan Oxigen, all through a Sigma 105 macro stopped at F/4, ASI1600MMC with 6nm Astronomik filters. I'm planning to shoot RGB data too and make an RGB/HOO composition. Cheers and clear skies! astrobin link: https://www.astrobin.com/r22yre/ flickr link: https://www.flickr.com/photos/170274755@N05/49939128338/
  8. 17 points
    Beautiful solar viewing today, just a tad breezy. Here's a time lapse from this afternoon, it covers approx one hour in the life of today's biggest prom.
  9. 17 points
    Reverse-Engineering the Skymax 180 What follows should be of interest to anyone who wants to know any of the following 3 things about this scope. 1. What it looks like inside, its design, how it works, and how to dismantle it and re-assemble it safely (yes I’ve seen that video of someone disastrously taking apart a Skymax 150!). 2. Its real dimensions, including all the major components of the scope including internal mirror separation/s; 3. Its “key numbers” such as effective focal length for various amounts of back-focus or mirror separation, to allow more confident estimation of magnification, fields of view, exit pupil sizes for various configurations. When I went to try to find these details, I couldn’t find anything reliable online. It started by me noticing that the Moon, always very close to 30 arcminutes across, was filling more of the field of view than the official spec of the scope suggested it should. The scope’s advertised focal length is 2700mm, but it seemed that in the set-up I was using it was behaving more like a 3000mm. That set-up was an external Baader Diamond Steeltrak, adding quite a lot to the back-focus compared to the supplied visual back. I did a little searching around, and quickly came across the formula for the effective focal length of a catadioptric: namely EFL = f1.f2/(f1-f2-s) where “s” is the separation between the mirrors. Seeing as the focus-mechanism relies specifically on changing this separation, I had all the excuse I needed to do something I’ve come to enjoy doing: survey the scope and/or take it apart to see how it works. At the same time I also did a focuser-axis-vs-primary-optical-axis test, and discovered that the two axes differed by around 8 arc-minutes; enough to investigate trying to fix it. As it turned out, this was not a problem, it was a design feature (more later)! Anyway, to investigate, I was going to have to see how the primary mirror was affixed to the central tubes and how if at all it might be adjusted, and to do that I was definitely going to have to take the scope apart. Unfortunately as stated I couldn’t find anything online either about how properly to take it apart, in particular the mirror, focusing and collimating end; and neither could I find anything I trusted about its various dimensions. I did find one article whose author calculated back-focus and EFL relationships for a Skymax 180 of almost identical age to mine, and who even went as far as to run its dimensions such as he had them (including corrector-plate refractive index!) through a ray-tracing program; but many of the dimension inputs he used I think must have been assumed or guessed: when I measured and re-measured them I found them very different from his. And the formulae are extremely sensitive to those dimensions being accurate. Disassembly, Adjustments and How It Works The rear assembly comes apart into 2-3 main pieces: the main rear cell, i.e. the cast-metal “back end lump” of the scope you can see from the outside, out of the back of which is poking the focus knob and the visual back; and the inner mechanism comprising the 2 nested baffle tubes, the primary mirror, the focus-mechanism and the collimation-plate. The primary mirror, outer baffle tube and the focus-rod receiving plate are all effectively one bonded-together piece. Although the mirror sits against a flange in the outer baffle tube, it’s heavily bonded on so trying to address any baffle-tube orientation problems is nigh impossible. The inner baffle tube, which sits inside the outer one, becomes at its bottom a stamped flat-metal plate with three threaded holes and a cut-out recess to allow the focusing-rod through. The three holes correspond to the main collimation bolts at the back of the scope, and they are the only things supporting the primary mirror assembly inside the OTA. In other words, those 3 collimation bolts hold the entire mirror and baffle-tube assembly inside the OTA space, and adjusting them points it around inside the OTA. What this means is that the visual back on the OTA IS NOT DIRECTLY CONNECTED TO THE BAFFLE TUBE. There is a gap, and potentially an axis-kink. See my drawing, comparing the Skymax to my Intes M603: What it also means is that blindly removing those 3 collimation bolts as a first step will cause the mirror assembly and baffle tubes to, at best, hang off the focus-rod inside, and at worst, if you’ve already removed the focus receiving bearing from the rear cell, the whole baffle and mirror will be set free to collapse onto the corrector plate and secondary! Therefore: if you really wish to dis-assemble, follow my instructions below! This arrangement is interesting. In my Intes, the visual back is part of the baffle tube which extends all the way through the rear cell: eyepieces, diagonals and cameras attach directly to the baffle tube. In the Skymax here, the visual back is part of the rear housing of the OTA, only attached to the baffle tube in a subsidiary fashion via the collimation bolts, and the whole “viewing tunnel” is effectively kinked at the rear of the scope. So collimation on the Skymax is mostly getting the baffle tube to line up with the visual back and eyepiece axis. That certainly helped explain why my eyepiece axis and mirror axes were “out” when I measured them. But if there’s misalignment of the corrector plate, or if the secondary mirror-spot is out of place, then I guess there’s little you can do about it. The native focus mechanism is very simple, far simpler than that of the Intes. It comprises a threaded rod held at one end by a bearing in the main scope back cell, and at the other end attached to a rigid metal plate bonded behind the primary mirror. Turning the knob causes the plate (and hence the mirror and outer baffle tube) to move up and down the tube at a rate of about 0.8mm per knob-turn. Obviously, there must be a tiny amount of clearance between the two tubes, and it’s this clearance that causes the dreaded “mirror slop” when the focus knob is engaged. Next came the front cell which contains the 18-19mm thick corrector lens, and appears to have coatings (green and pink reflections each evident). On the inside surface of the corrector lens is the secondary mirror, an aluminized spot surrounded by a cup-shaped black plastic baffle skirt. This skirt is glued to the secondary mirror, but in my case NOT CENTRALLY! I removed it, thinking in the process that I was reducing the Central Obstruction as well, but soon realised that because the primary mirror hole and retaining-ring were themselves much wider than the widest part of the secondary baffle-skirt, there was no point. Nonetheless having removed it, I cleaned off the residue, re-centred and re-attached it. With the baffle-skirt in place, the remaining exposed secondary mirror is 36.5mm diameter. The main tube itself was a loose fit: larger than the fitting-flange on the front cell, and smaller than the flange on the rear cell in each case by more than I was entirely happy with (it fits inside the lip of the rear cell and outside at the front cell). As such, the tube had to deform in each case slightly when doing up the 4 retaining screws at each end. I plan at some stage to get a carbon tube with a better fit. The dovetail is bolted to the tube, not to the much-more-solid cells, and the tube is only held on to the chunky front and rear cells by those 4 screws each end. Rings for this scope would be a good addition, or a longer dovetail to attach directly to the main cells. Step by Step Dismantling 1. Attach a visual back that extends beyond the focus knob. You’ll be using it to place/balance the rear assembly vertically on a flat surface later. 2. Remove rubber focus knob (it simply pulls straight off). 3. Rotate the protruding brass cylinder clockwise, to gradually expose the threaded rod. 4. Unscrew and set aside the small central Philips screw (and possibly small washer) at the top of the threaded rod (it may be a C-clip instead, in which case remove that). 5. Remove main telescope front plastic “lens cap”. 6. Place scope “front down” on a level surface. 7. Partially, maybe ½ a turn, unscrew the three main (bigger) collimation bolts at the back. BUT ONLY UNTIL THEY LOSE THEIR TIGHTNESS – DO NOT COMPLETELY UNSCREW THEM YET! THE MIRROR IS ESSENTIALLY HANGING OFF THESE SCREWS INSIDE THE OTA! Do not touch the smaller recessed “locking screws” – keeping them in place allows you to restore the position of the primary at roughly the same orientation when it comes to re-assembly. 8. Unscrew the 3 screws on the flange around the focus-knob, and set them and the flange-plate aside. 9. Unscrew, by hand, and set aside the exposed brass focusing assembly (ACW) all the way off (perhaps 20+ turns!). Also notice and remove a black rubber washer underneath the assembly. Be careful of the evil black grease! 10. The threaded rod, covered in black grease, will now be poking up through the hole in the back plate. 11. Unscrew and set aside the 4 screws on the side of the OTA holding the rear cell to the main OTA around its outside. From here you need to be very careful with your movements to avoid things getting knocked and toppling over. 12. Lift the whole rear assembly out of the main tube and carefully place it on the level surface “focuser down” (i.e. collimation screws and visual back at the bottom). 13. With a small/short hex socket-insert, with your fingers from underneath, carefully unscrew/twiddle off all the way the 3 main collimation bolts that you loosened earlier. Once done, the primary mirror assembly and baffle tubes are now only resting on the OTA’s rear cell. 14. Whilst supporting the rear cell on your flat surface, and holding the baffle tube, gently lift the baffle tube (and primary mirror and focus-rod) away from the main rear cell. Be careful not to lose 3 hidden fat little washers between the plate at the bottom of the baffle-tube and the rear cell: they can stick to the underside of the plate and fall off later if you don’t pay notice them. 15. Remove the O ring around and near the top of the inner baffle tube. This O ring prevents the outer tube from sliding all the way off if somehow the focus-rod isn’t holding it. It’s tricky to remove with all the grease lubricating the two tubes: try not to damage it. 16. You can now separate the two tubes by pulling the outer tube off the inner: the outer tube with its mirror, focus-plate and (evil-black-greased) focus rod; and the inner, with its flat plate at the bottom. 17. Further dis-assembly of the primary mirror and its components is not possible, as you will see that the primary mirror is extremely heavily bonded in place on its tube. Re-Assembly 1. Place the rear section on the hard surface, resting on the Visual Back 2. Place the 3 fat doughnut black rubber washers on the 3 larger collimation-holes (they act as crude tensioning-springs for the collimation-bolts) 3. Carefully place the collimation-plate/inner baffle-tube so that its 3 holes match the main collimation holes, and such that the focus-knob cut-out matches the focus-hole in the rear cell 4. From underneath, using a short suitable hex-insert, screw in the 3 main collimation bolts most of the way, but do not tighten 5. If necessary, re-grease the lower part of the baffle tube where the outer will slide over it 6. Gently and carefully lower the primary mirror / outer baffle-tube onto the inner one 7. Re-fit the rubber O-ring into its slot 8. Remove excess grease from the upper end of the baffle tubes 9. Bring the 2 halves of the scope back together again: carefully lower the rear assembly back into the main tube, and re-attach the 4 screws. The scope should now be on its front, with the visual back “up”. 10. The black-grease threaded rod should now be poking up through the focuser-hole. Replace the black flat rubber washer into that recess 11. Screw on the focuser assembly, “thicker bit” first, clockwise onto the threaded rod until it’s all the way into the recess, and a couple of turns more. 12. Screw on the small locking screw onto the end of the threaded rod (or replace the C-clip if that’s what it is) 13. Replace the flange-plate and secure it with its 3 screws 14. Push the rubber knob back on 15. Screw the (larger) collimation-bolts back until they are reasonably firm: having not touched the smaller locking-screws, this last action returns the primary mirror assembly to close to the orientation it was before you started. Dimensions and Measurements A. 45.4 mm: Front Rim to centre of Corrector Plate B. 18.6 mm: Thickness of Corrector at Centre C. 42.5 mm: Depth of Secondary Baffle Skirt D. 421.5 mm: Front Rim to Front Rim of Rear Cell E. 357.5 +- Nx0.787 mm: Secondary Mirror to Centre of Primary Mirror where N = no. full turns ACW from where supplied visual back & 2” diagonal come to focus (more back-focus => smaller separation => bigger focal length) F. 83 mm: Front of Rear Cell to Flat Back of Rear Cell (not including Visual Back attachment!) G. 37 mm: Exposed Diameter of Secondary Mirror H. 58 mm: Secondary Baffle Skirt Width (at wide end) I. 42.5 mm: Depth of Secondary Skirt J. 63 mm: Diameter of Primary Mirror Retaining Ring (i.e. wider than secondary skirt!) K. 200 mm: Primary Mirror Diameter (i.e. oversized) Other quantities not shown on diagram: F1: 472 mm: Primary Mirror Focal Length (measured as half the centre of curvature, itself measured from its reflecting a point source F2: 127.92 mm implied Secondary Mirror Focal length (to force formula to give 2700 mm with supplied back and diagonal and all other measured dimensions. Very difficult to measure). also: - 0.787 mm pitch of focus-knob (movement in primary for one full turn of native focus-knob) - 665.3 mm Circumference of lip of front cell (=> diameter 211.8 mm) - 670 mm Circumference of inside of OTA tube at front (=> diameter 213.2 mm) - 1.60 mm OTA tube thickness - 682 mm circumference of INSIDE lip of rear cell (=> diameter 217.1 mm) - 681 mm Circumference of outside of OTA tube at rear (=> diameter 216.8 mm) The way the main (steel) tube fits on to the front and rear cells is worth taking note, if you plan to fit a carbon tube, for instance. The tube slots OVER the cell at the front, but INSIDE the cell at the back. The difference between the two meeting-face diameters is 217.1mm less 211.8mm, i.e. 5.3mm. Which means that should you wish to upgrade to a, say, carbon tube, it would need to have at most 2.65mm wall-thickness. The steel thickness on this scope is 1.6mm, which is accommodated by the fact that it’s flexible, and on this scope at least needs to flex to fit. The native focus mechanism is, as shown, a knob on the back which moves the primary mirror up and down the tube. The secondary mirror is fixed in place as an aluminized spot on the back of the front corrector lens. Focusing via that knob changes the separation between the mirrors, changing the focus-point and back-focus and changing the system’s Effective Focal Length, according to the formula EFL = - f1.f2/(f1 – f2 – s), s being the mirror separation. If I could simply find out what the individual focal lengths of the two mirrors were, and what the mirror separation was for given positions of the focus knob for a given back-focus amounts, I could calculate what focal length a given arrangement engenders, and therefore construct a more accurate mag / exitpupil / FoV ready-reckoner to stick to the side of the scope. I started by roughly estimating what these numbers might be just by “eyeballing” the scope, doing some crude measuring and putting together a simple spreadsheet. I hoped that would be close enough and I wouldn’t have to dis-assemble. For instance f1, based on reflecting a point source back to itself from the mirror seemed about 450mm, f2 around 90mm and judging by where the main mirror looked positioned, the mirror separation looked something like 370mm. Then I noticed something about the EFL formula. f1 x f2 is going to be a reasonably large number, in this case 40,500. f1-f2-s is going to be quite a small number, here -10, suggesting an estimated EFL of 4050mm. Hmmm. Big number divided by small number is going to be very dependent on the small number, especially if that small number is a difference in measurements. It doesn’t take much leeway in those numbers for that denominator to be, say, 0mm for example and the calculated EFL to become infinite. Or even negative! Clearly, more precise dimensions rule here. “Rough estimates” weren’t going to cut it: I could come up with whatever results I wanted just by slightly varying the key dimensions. I was going to have to make accurate measurements. Two of these accurate measurements initially presented a challenge: the precise thickness of the corrector lens (the mirrored spot is inside the tube and at the centre of a highly curved and rather thick glass plate); and the precise position of the centre of the primary mirror (it’s recessed into the rear cell of the scope, has a big hole where its centre should be and you can’t see the thread which moves it). I needed to be ingenious about each of these. My digital micrometer saved the day. The back end of it can be used as a depth gauge, and using it I was able to accurately estimate the thickness of the corrector plate and, because the primary mirror is recessed into the rear cell, the distance below the rim of the edge of the primary (I also needed to take account of the sagitta of the primary). The distance between the front and rear cells was trivially measured from outside the fully-assembled tube. And finally, using the pitch of the threaded focusing-rod, I was able to determine the mirror separations for any position of the focus-knob. Effective Focal Length and Back-Focus All the above having been done, I was now in a position to estimate EFL for various back-focus settings, and for my various actual set-ups. These estimates are predicated on the assumption that with the supplied diagonal and Visual Back, the focal length is actually as indicated on the scope’s plaque, i.e. 2700mm. The only quantity I couldn’t easily measure, the focal length of the secondary, was the “degree of freedom” I could change that allowed me to “fix” the EFL to 2700 for a certain set-up. At some stage I’ll try to actually measure it, but this will do for now. Below is a chart showing Effective Focal Length of the Skymax180 against the likely range of back-focus behind the OTA: The geometry means that actually the EFL is a linear function of back-focus, which surprised me (see formula below). Incidentally the 440.5 is the distance from the secondary to the back of the OTA. For the Skymax 150, for example, the formulae would be the same but with a different value of “440.5” (I’ll update this post with Skymax 150 values and dimensions when I get back to London). A couple of extra data points that I didn’t include on the chart are those for the “end-stops” of the native focuser travel, i.e. 0 turns ACW and 29 turns ACW: 0 turns => -40mm backfocus (i.e. inside the rear cell!) => 1952mm EFL => 375mm mirror separation 29 turns => 1113mm backfocus => 6200mm EFL => 354mm mirror separation For those who prefer formulae to calculate these things: Effective Focal Length EFL = (BF+440.5).F1/F2 + F1 all quantities in mm; BF measured from rear of OTA Mirror separation s = F1 – F2 + F1.F2/EFL In the use of these formulae for estimating the various quantities, I’ve ignored the effect of the corrector plate. The only exception was the measurement of the Primary’s focal length, which I measured with the corrector plate removed. I don’t think it matters too much, and hopefully is partially compensated-for by my back-solving of the focal length of the Secondary to achieve 2700mm in OEM configuration. (Re-)Collimation I now had knowledge of what was mechanically going on behind the mirror and what the collimation bolts did! As mentioned, those 3 bolts are the only things attaching the primary mirror support assembly to the rest of the scope, and they basically point the mirror around the inside of the tube. The secondary is fixed, the visual back attachment is fixed, the only thing that you can change is the orientation of the primary inside the tube. Thus collimation involves aligning the primary’s axis as well as possible with the visual back’s axis and the centre of the secondary. If either of these are out of place, it’s an exercise in compromise. A popularly suggested method for aligning Maks and SCTs etc is the “hall-of-mirrors” method. But I’ve found it unsatisfactory: it can tell you if you’re reasonably close, but if you aren’t it doesn’t tell you what to adjust to get it right. I’ve found that star-test collimation is much more intuitive and sensitive. Point at something like a 2nd-mag star, ideally Polaris because it stays still, on a night of not too bad seeing. Using at least a 10mm eyepiece, and very slightly defocusing, you'll notice a set of concentric(ish) rings around a small hole with a point in the middle. Very likely though, the doughnut you see will be "squashed" towards one edge. Establish which collimation bolt best corresponds to that squashed position, by putting your hand over one side in front of the scope and seeing where the gap appears in the view: the bolt closest to that gap, or the one opposite, is the one to move first. Adjust that collimation bolt, and the squashiness will either improve or dis-improve. One proviso: as you turn the collimation, the star will move out of view, so have your controller handy so you can keep it in view during the process, to avoid spending 10 minutes re-discovering Polaris at high magnification (been there, done that). Keep going through that process until the ring-pattern is as symmetric as you can make it. I find that it comes right quite suddenly at the end. You could go one step further to do super-fine collimation (I often don't bother) by going to super-higher magnification, getting to best focus, and "symmetricizing" the Airy disc, but to do that you need almost perfect seeing which is rare. Whereas symmetricizing the doughnut can be done on more ordinary nights and gets you very close. Once there, it should hold reasonably well for the future. People call catadioptric collimation a "dark art", and one of the reasons I think is that the various internal designs are often very different, and collimation is doing different things "inside". And they never tell you what's inside, so you are effectively adjusting something by blind trial and error hoping that whatever it is lines up. If you’ve got this far, well done! And thanks. I hope this will prove useful to anybody else with a reason to want to know how this scope and its siblings (Skymax 150, 127 etc) actually work inside. Cheers, Magnus
  10. 16 points
    I spent some time this evening cutting back the laurel hedge in my observing area and getting it properly sorted. It is much better now, much more space and more comfortable to position my seat around the scope. I was mainly using the Mewlon 210 with binoviewers tonight, and had some really wonderful views. The Jura mountains looked spectacular, as did Copernicus. Rimae Hippalus were showing very clearly, looking like three curved claw marks across the surface. Helped by some prompting from @PeterW I caught the domes near Milichius, and that encouraged me to find the Hortensius domes, and finally Kies Pi Dome which was tricky but I found it after referencing an image off the web. I found Copernicus H, and then also spent some time trying to identify other Copernicus craterlets, getting up to F before calling it a day. Checking other Lunar 100 features best on day 9 (looking at day 10 seemed less effective for some reason), I saw the Imbrium lava flows at number 98. Referencing @Doc’s very useful notes, I identified the areas mentioned, although it would be great to have an image to cross reference against to verify I was in the right place. I tried for Lambert H but couldn’t convince myself I was seeing it, pretty sure I was looking at two other smaller circular features so will have to come back to this one, I assume it is very critical in terms of lighting so will just try again at different times around this phase. Three or four Plato craterlets came my way too which was a good addition to the haul. To finish up the session, M57 looked very good considering the brightness of the moon, and M13 was resolving very well deep into the core, although no propeller was visible to me. Darker skies perhaps. Finally, and the reason for the title, after much rustling in the leaves my lovely little hedgehog joined me at the scope, hoping for a look too no doubt. Lovely to see and finished off a very enjoyable evening.
  11. 16 points
    The idea was to identify where Apollo 11 landed and then locate the tiny craters Armstrong, Collins and Aldrin but I got carried away. I went back to this area two nights running and decided to sketch a big area. Two rimae, clear cut boundary between the dark mare region and the lighter material of the highlands, Sabine and Ritter have very rough floors with hints of terracing and circular cracks, wrinkle ridges abound, dark and light regions in the mare, sharp pointed shadows, the lighter slopes rising up from the dark flat mare, partially flooded crater (Ariadaeus E.) at the end of R. Ariadaeus, which at the far right cuts through the Silberschlag Ridge. So much going on. Mike
  12. 15 points
    My usual setup :- 152mm F5.9 Technosky Achro AZEQ6-GT... Daystar Quark Chromosphere Baader 135mm D-ERF gives effective F30 ish Point Grey IMX174 HP Pavillion, 16GB,i3-5010U @ 2.10GHz Sammy 850EVO SSD (in case people were wondering) Aquasition Details:- 29/05/2020 12:28:32PM - 12:50:41PM 1658 Frames, 10 sec capture, EXP 6Ms, Gain 20935,Gamma 1, Pixel depth Mono16, FPS 141, Stacked 50%, ImPPG, Normalised, Aligned then Gimp 180.tif 185.tif 308.tif 532.tif 675.tif 730.tif 860.tif different.tif
  13. 15 points
    30 minute animation of Hedge Prom 1 frame captured every minute for 30 minutes. Each frame was stacked from 10% of 800 frames.
  14. 14 points
    This is 16 x 600s Subs 2x2 in OIII and SII and 16 x 600s 1x1 in Ha combined as SHO. Acquired over the last 3 nights with a total integration time of 8 hours representing the most I've ever got on one object - pathetic I know. It so much easier to process with more data, I really most make the effort to stay at least 6 hours on each target. I've probably spent at least that amount of time playing with the look and feel of this, i can't seem to get the gold look that makes the Hubble pallet so appealing. Also included is a detail from the main image with possibly a more appealing framing to it.
  15. 14 points
    This is Abell 2151 aka The Hercules Cluster of Galaxies. It’s 500 million light years away and it has about 200 galaxies. 123 galaxies annotated in this image with my field of view and some of them are very special. Let’s have a look at some of the more interesting galaxies. NGC 6041 is the brightest galaxy of all of them. It’s 220,000 light years in diameter, way bigger than the Milky Way and it is 480M light years away. A bit above we find ARP 122, a pair of interacting galaxies. It’s not obvious in my image, but NGC 6041 is a bit distorted towards ARP 122, so all three galaxies are interacting. ARP 122 is in a category where the elliptical galaxy is distorting a spiral galaxy. Further down the image we have ARP 172. These are in the category “Galaxies with diffuse counter-tails”. You can see how the tails of both galaxies are diffuse on opposite sides of the galaxy centers. ARP 71 is in the category of “Spiral galaxies with small high surface brightness companions”. It’s an oddly specific category, but definitely applies to this pair. NGC 6045 is 180kly in diameter and the pair is 447MLY away. ARP 272 is probably the masterpiece of the Hercules Cluster. Three spiral galaxies are in a beautiful dance (or dance macabre if you will), where they will devour and distort each other. These are 500MLY away. I wanted to note the large star in the top of the image. It’s poetic name is TYC1507-998-1 and it is of magnitude 6.75. So it’s actually not visible with the naked eye, but it is blowing out this image. Loads of other interesting galaxies. Go explore, I’ve spent a few hours on this image and more can be found.
  16. 13 points
    I’ve been wanting to put these two side by side since getting the Vixen, and after sorting out my observing area and getting the Rowan AZ100 in a better place, I finally did it last night. The AZ100 performed beautifully on the Planet tripod once balanced correctly, which involved bring the Tak back quite a long way in its rings because of the lightweight prism and orthos. The slo mo controls are actually much quicker and easier to use than the handset on the Vixen GP, more intuitive to get the direction right and quicker skews. This more than offsets the loss of motorised tracking I think so I will use this setup for solar white light and Ha in future too. I’ve popped a couple of pictures of the solar setup in here for reference. To try to keep things as fair as possible, I just used Baader Genuine Orthos, and rather handily a 5mm and 6mm gives x148 and x150 respectively (Tak then Vixen). Originally I was going to use the Baader Zeiss T2 prism in the Vixen, and the Baader BBHS T2 Mirror in the Tak, but after an initial look and swap between scopes, I could see a definite benefit in the prism, a little sharper and more contrasty. What to do? I then tried my Tak Prism, which despite some recent comments to the contrary I find very good, and it levelled things up nicely so I felt it was now a fair fight. That in itself was a surprising finding, the mirror in the BBHS has recently been replaced so should be at top performance. Initially I viewed with a 12.5mm and 9mm, but felt like the mag difference was too much for meaningful results, so switched to the shorter focal lengths and set to work. I observed many different features, trying for threshold craters and rilles which I thought might separate the two. I looked at Plato craterlets, the Copernicus craterlets, detail on the sides of smaller crater walls, Messier and Messier A and domes. I wasn’t so worried about knowing the names of what I was looking at, just comparing the views. The result? Under the fairly steady conditions I had last night, and at x150 mag, I was unable to separate them. On occasion I would switch from one to the other and think that the second one gave a worse view, but it was only ever down to seeing variations. When the seeing was the same, the views were the same. My old favourite Izar showed identical, and beautiful views in both scopes. Perfect airy disks and diffraction ring, clear separation and colour difference between the two components. The Double Double initially looked a fair bit better in the Vixen, and the faint star nearby did not show in the Tak. Curious? Yes, but problem solved by a quick defocus which showed the leaves of the hedge cutting into the Tak view! Once clear of this, the views were the same again. I will try again with some tighter doubles when I get the chance to see if I can tease any differences out. So, I have one old and one new scope, both 4” and both giving excellent performance. What to do? My only decision is to keep both! I love the look and character of the Vixen, and the portability of the Tak. The Vixen has the longer focal ratio and gets to x300 with the Nag Zoom vs x246 for the Tak which is useful on occasion. The Tak binoviews easily, the Vixen doesn’t seem to have the inwards focus, although it may with the Tak prism. I often leave the Tak setup for Solar white light, but the Vixen won’t reach focus with my Baader CoolWedge, so knowing I’m not missing anything with the Vixen I can keep the Tak for Solar during the summer and use the Vixen for Astro. So, a rather dull, but still interesting score draw I think. Please forgive the old loo seat in the pictures.... being kept for firewood at some stage!!
  17. 13 points
    Hi guys More Mono testing I was able to nab a small amount of Oiii last week to add to the small amount of Ha i'd already captured the week before. I should be getting my very own Atik383l+ in the very near future (yay!), but for now i am still exploring the virtues of Mono imaging using the Qhy9 that Adam @tooth_dr kindly lent me. I had balance and guiding issues again this time, despite the fact id' spent a lot of time on trying to get it right. I think after 7 years it may finally be time to get the mount serviced. It has quite a lot of stiction, in both Ra and Dec, which is making getting balance an exercise in pot-luck, so i think a trip to DarkFrame for a Hypertune may be on the cards soon. After losing half the (already short) Nautical Dark that was available, i finally got the guiding working just in time to get 5 subs, all 20 mins long each. The last sub was actually shot in Civil Dark! So in total this is just 100 mins Ha and 100 mins Oiii using 20 min subs (all 2" Baader filters) using a SW 80ED. Stacked in APP and processed in PS with Starnet used for star removal. Combined as OHO due to the lack of any Sii. I tend to like my NB fairly colourful, so this may on the 'over-processed' side of things, especially due to the low amount of data. I'm still learning the ropes of mono imaging so always interested in hearing feedback. CS and stay safe folks.
  18. 13 points
    Hello all I’ve been visiting these forums for a little while now and have recently taken the next step in astrophotography and thought that I would step forward to introduce myself and share what I consider a recent successful outcome, despite the limitations of what I am currently imaging with. To give you a little background, I have been interested in astrophotography for a number of years, with a particular enthusiasm for deep sky objects. However, I have been hampered by a very limited budget until more recently. I originally started imaging with a Meade ETX 80 and DSLR with limited success due to the limitations of the scope and built in mount. I’ll come back to this scope shortly. I then purchased an iOptron Skytracker, which again gave me limited success, partly because I was asking a little to much of this. I intend on returning to the ioptron this summer to capture the Milky Way. My astrophotography endeavours have taken a back seat for the last couple of years after I moved house and having spent most of my spare time working on it and being tired by the end of the night. However, living in a home that has dark skies, which I can image in almost all directions, and with my finances somewhat improved nowadays, I decided to take the leap and purchase my first proper guided mount setup in the form of an HEQ5 Pro, SkyWatcher StarTravel 120, field flattener, ZWO Mini Scope, ZWO 120mm mini guide camera and modified Canon 1300D. I understand the limitations and pitfalls of this scope, but it is very much a beginner setup while I learn the craft and hone my skills, and once I am worthy I will upgrade it in year or two to an apochromatic. I can also edit CA to an extent in the early days However, with the world currently broken as it is, everything has arrived with the exception of the Startravel, which I am told is stuck in Chinese customs. So I have a guided setup without a scope, which I still await with anticipation. However, not perturbed by this setback, I decided to test the rig during the last new moon by fashioning a homemade attachment for my EXT80 to see whether I could at least guide successfully. In addition to this setup pushing the balance, actually finding the targets was initially difficult. Don’t get me wrong, EQMOD and Catres Du Ciel amazingly worked perfectly without the need to troubleshoot (lot of hours reading sites and forums in advance) but because I have a scope with a goto mount that can move independently of the guide setup, and which doesn’t particularly lockdown very tightly, I had to position the scope independently once the mount was locked onto the target. However, once I got over this hurdle, the modest images that I obtained have really filled me with enthusiasm and encouragement for the future and I look forward to the next new moon. Both of these images are taken with the above setup and a Nikon D7100, PHD2 and APT and stacked with DSS and edited with Photoshop CR2. 22 May 2020 Leo Triplet 60 minutes of lights (20 x 180 secs) at ISO 1600 and 10 dark, 10 flats and 10 bias 27 May 2020 & 27 May 2020 M81 & M82 154 minutes of lights (21 x 240 secs and 14 x 300 secs) at ISO 800 and 10 darks, 10 flats and 10 bias I still have a lot to learn but with patience, practise and research I hope to build on these early successes and produce further images to share soon, which if my scope arrives in the next couple of weeks will be a crack at the Eagle nebula this month, weather permitting. Anyway, this is rather a long introduction and I appreciate your time. Jem
  19. 13 points
    Another clear start to the day so had to get out and see what was going on. Still lots of activity both in white light and Ca-K. Seeing generally not as good today as yesterday but still passable at times. Ca-K FD's Nice little plage area @2500mm focal length Proms @1000mm focal length, shot binned 2x2 Managed to catch some nice granulation in white light. Worth clicking these for the full size image. And finally the active region @2500mm focal length in both white light and Ca-K
  20. 13 points
    When I speak to normal people who don't have an interest in astrophotography I find they ask a number of common questions such as: Where is this object? How large is it? Are the colours real? And the most common; how much magnification is required to see it? I have therefore set about collating images into easily identifiable areas of the night sky, typically constellations. By presenting these against a widefield whole constellation image correctly rotated and scaled it is possible to provide context to the objects and hopefully help answer some of these common questions. Video seems like a a sensible way of presenting this data because it allows motion and the ability to see closer versions of the objects. So here are Ursa Major and Coma Bernices. Ursa Major is one of the most obvious constellations in the sky and it is littered with galaxies. It has taken me 18 months to amass the source images and there are many more to go...
  21. 13 points
    I know I can only go so far in terms of detail when taking snap shots of the moon with my old mobile phone at the eyepiece of my scope and I reckon I've more or less reached the limit here. I wanted to try and capture the Hadley Rille and the Apollo 15 landing site that was showing so crisply though the eyepiece of my 12 inch dob. This is the best that I could do. I've put an old NASA map extract of the landing site area next to it with the point at which the Lunar Module landed marked with a red arrow on each image. Considering this was taken at about 400x magnification with an undriven dob and a cheap camera bracket I'm actually quite pleased with it. The eyepiece view was a lot crisper than this - probably one of the best views of this area of the lunar surface that I've had for a while. For scale, the crater that sits on the Rille below the landing site (in the pictures) is Hadley C with a diameter of 6km. I guess I'll need to upgrade the mobile phone if I want to do better !
  22. 13 points
    Or possibly the Witch's Broom. 6 hours each HII and [OIII] in 10 min subs. TS Photoline 130mm f/7 apo, ASI1600MM-cool, 3nm Astrodon filters withy significant moonlight. Processing in AstroArt, Sigma Add stacking of each 3 hour session then added. Gradient Removal, Trichromy DDP and Histogram Stretch. Saved as JPEG. This will have to stand for the moment until I can get [SII] which may have to wait until teh moon is out of the way. I think i've pushed the levels a bit so will have another look.
  23. 13 points
    Decided to take my first astro image for 8 years and first planetary image for 12 years. Decided to have another go spurred on by the approaching favourable Mars opposition in late summer / autumn. Despite its incredibly poor viewing angle from the UK, I settled on Jupiter as the first target. I must be nuts, up at 2.45am on a work day to image a badly placed planet. Whole thing was an exercise in frustration. Neighbours trees proving a real problem for starters. The only spot i could see Jupiter was the one spot I couldn't see Polaris. So naturally polar alignment was flakey and Jupiter refused to hang around. Seeing was also poor. But after an hour and half i had a handful of movies to process. The best of which produced the image below. Yes I know, not exactly an illustrious return to imaging.... Kit used: Skywatcher HEQ5, 200P, Explore 3x barlow (thank Craig), QHY5L-II C. Captured with Sharpcap, stacked in AS3, wavelets in Registax 6 and final tweak in Luminar 4.
  24. 13 points
    Just stacked my Ha on the remote laptop, but could not process it as everything was posterised through TV, so sent it to myself using Wetransfer and I've done a quick process on the desktop indoors.
  25. 13 points
    Three hours and 10 minutes of data from 2 nights! A quick stack in APP, LP removal and tidied up in PS. It looks like I need to take new calibration data. This was experimenting with 120s subs.
  26. 12 points
    I just caught the better seeing before the trees grabbed the sun.
  27. 12 points
    I caught something, prom and active area as seen buy my poorly cam. kit starwave 102 f11,quark, asi120mc +sticky tape. thanks for looking. keep safe, clear skys. charl. prom upper off going limb. active bit.
  28. 12 points
    Wide and in context, and a closer view. Taken with the RC8 and TS71, bothe using the QHY9 CCD
  29. 12 points
    I just waited for the sun to be safely behind the house and found Venus through the Tak What a beautiful sight! The ultra slim and fragile crescent hanging against a lovely blue sky. Perhaps the last look at what has been a great showing
  30. 12 points
    Hello all, Finally found some time to make another astrophoto (was 5 months ago...). I sustained a pretty bad cycling accident in February and was only able to carry my equipment outside again about 3 weeks ago. Great to be able to make an image again. This one was on my bucket list for several years and I have spent 20 hours on it the last couple of days. It's a 2 panel mosaic of a very faint and rarely imaged patch of nebulosity next to DWB145 in Cygnus. Thanks to Nicolas Outters for the inspiration! Scope: 10" f/3.8 homebuilt Astrograph with 3" Wynne corrector CMOS: ASI-1600 MM Cool (-15°C) Filter: Astrodon 5nm h-alpha Exposure: 20 hours in 5min subframes (2 panel mosaic) Mount: Mesu200 Thanks for checking it out, Pieter
  31. 12 points
    NGC7008 is a planetary nebula located in Cygnus about 2800 light years distant and about 1 light year in size. The amateur astronomer Eric Honeycut named it the Fetus Nebula when he viewed it through his 22inch reflector. Planetary Nebula are one of the few astronomical objects that may appear green, so when processing this particular object you have to be careful when eliminating green from your image (eg SNCR green in PI) otherwise it will significantly change the colour balance of the object. Since it is so small and there's not much of interest in the background, I decided to crop it quite aggressively, so that a few details of the nebula can be seen more easily. So, here's an LRGB image consisting of 13 hours integration which was taken with my Esprit 150. Alan LIGHTS: L:26, R:17, G:17, B:18 x 600s, DARKS:30, BIAS:100, FLATS:40 all at -20C.
  32. 12 points
    Been a long time since I had the opportunity to spend a bit of time gathering data. Native F9 with the little RC6 on my HEQ5 with an Atik 460ex for an LRGB image of around 12 hours total. 2x2 binned RGB. Multiple sessions and a lot of discarded subs due to rustiness and those pesky high clouds blowing over, but more than happy with end result. Nice to be back processing my own data.
  33. 12 points
    A couple more images captured this morning. First light for my improved solar camera, a Hypercam 174m. A vast improvement on the GPCAM v1 I used a couple days ago. First image is a 2 pane mosaic. I'm using a diagonal before the Quark so it's reversed in both axes. 2nd image is the left hand pane of the mosaic inverted to show the solar inhabitants I've just discovered!
  34. 12 points
    This was just a very quick session as we won't have any true Astro darkness for a couple of months. I was unsure what I was going to do and then saw that M3 was ideally placed for me to grab a few hours as I didn't want to waste the lack of the moon. I have reprocessed this about 3 times as I knew there was some nice gentle star colour, hopefully I have respected that they aren't strong but subtle colours. Capture details: - 10" GSO/Altair RC Truss, Moravian G2-8300 Mk!!, iOptron 120EC Mount, Ultrastar Guide Camera, Chroma 2" Filters, QHY OAG. Processed in PI and PS 2020 Chroma Blue 2" unmounted: 8x390" -20C bin 1x1 Chroma Green 2" unmounted: 8x300" -20C bin 1x1 Chroma Luminance 2" unmounted: 11x300" -20C bin 1x1 Chroma Red 2" unmounted: 8x348" -20C bin 1x1 Further details here: - https://www.astrobin.com/7z8grc/ Anyway, here's the bumf: - Messier 3 (M3 or NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici. It was discovered on May 3, 1764, and was the first Messier object to be discovered by Charles Messier himself. Messier originally mistook the object for a nebula without stars. This mistake was corrected after the stars were resolved by William Herschel around 1784. Since then, it has become one of the best-studied globular clusters. Identification of the cluster's unusually large variable star population was begun in 1913 by American astronomer Solon Irving Bailey and new variable members continue to be identified up through 2004. Many amateur astronomers consider it one of the finest northern globular clusters, following only Messier 13. M3 has an apparent magnitude of 6.2, making it a difficult naked eye target even with dark conditions. With a moderate-sized telescope, the cluster is fully defined. It can be a challenge to locate through the technique of star hopping, but can be found by looking almost exactly halfway along an imaginary line connecting the bright star Arcturus to Cor Caroli. Using a telescope with a 25 cm (9.8 in) aperture, the cluster has a bright core with a diameter of about 6 arcminutes and spans a total of 12 arcminutes. This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is estimated to be 11.4 billion years old. It is located at a distance of about 33,900 light-years away from Earth. Messier 3 is located 31.6 kly (9.7 kpc) above the Galactic plane and roughly 38.8 kly (11.9 kpc) from the center of the Milky Way. It contains 274 known variable stars; by far the highest number found in any globular cluster. These include 133 RR Lyrae variables, of which about a third display the Blazhko effect of long-period modulation. The overall abundance of elements other than hydrogen and helium, what astronomers term the metallicity, is in the range of –1.34 to –1.50 dex. This value gives the logarithm of the abundance relative to the Sun; the actual proportion is 3.2–4.6% of the solar abundance. Messier 3 is the prototype for the Oosterhoff type I cluster, which is considered "metal-rich". That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements. https://en.wikipedia.org/wiki/Messier_3
  35. 11 points
    Finally, this project is completed and so is this season (I hope not)... The LRGB version of M51 is here..Took me 5 nights (1 in April and 4 in May) to image the whole thing. And very long to process. Wish to add Ha but its been cloudy since a week and a storm expected this week. Here's the Astrobin link https://www.astrobin.com/k6o2c0 I have not been able to get the star cores and colors right. Tried using HSV Repair Script in PI but to no avail. Please help me out with that. L : 220 x 60s R : 90 x 60s G : 98 x 60s B : 120 x 60s All frames at Gain 0 & Temp. -5C..while ambient stayed above 33C entire nights. Equipment Camera : ZWO ASI1600mm Pro Telescope : Skywatcher 130PDS Mount : HEQ5Pro Guiding : Orion 50mm guidescope, Orion SSAG Camera Filters: Orion LRGB Other/Accessories : ZWO FW, Pegasus Dual Motor Focuser Location : Gujarat, India. (Bortle 5) Thanks for looking.
  36. 11 points
    Heya, It's been a hot minute since I've seen the sky at all. Florida has been a hot mess of rain, humidity, storms, clouds, clouds on top of clouds, etc. Just nasty. Anyhow, there were a few sucker holes today between clouds but it was at the worst time of day for me for seeing and for the heat, 2pm... dreaful hour in Florida. But I guess desperation was in full gear. I waited between clouds to do each part of tuning, focusing, etc, for what seemed like a small eternity. I risked imaging through some visibly moving low hanging cirrostratus cloud groupings. Image scale is very course and undersampled as I was going for speed, full disc imaging was at 133 FPS on the IMX174 sensor at F10 through my 60mm Double Stack system. There was no hope for any high res today, sadly, for that wonderful prominence. There's a few active regions, one named (AR2764), some small but obvious filaments around these areas and one rather large prominence arching on the limb. There's some interesting light activity going on near the new AR that is rounding the limb currently. ED80 Solarmax 60mm Double Stack Etalons 10mm Blocking Filter IMX174 Very best,
  37. 11 points
    I got inspired by Dylan O'Donnell and his guide to shooting lunar transits of the ISS, so I subscribed to calsky and waiting. On the 25th I got the notification that I was due a transit on the 28th. It was only due to skim the edge of the lunar disc, but I thought it was worth a try. I went back and watched his guide again and planned my evening. First was camera choice, the ASI1600 just doesn't give a reasonable frame rate, and it's mono, so I went back to my Canon 600D. Dylan's guide suggests an shutter speed of 1/1600th or faster to get blur free images, which ruled out video on the Canon, so I tested the number of shots and the speed of them shooting in continuous mode. 6 shots in ~1.5 seconds and then the buffer is full. I played with the idea of shooting in a lower res jpeg format to see if I could get more images in the buffer, trying to get the timings perfect was going to be a challenge otherwise. In the end I went with raw and the assumption that I'd probably not succeed on my first attempt, so I'd learn something if nothing else. The night before I went out with and set up including my laptop, normally I use Stellarmate on a raspberry pi, but this time I also needed the canon software running on windows to trigger the continuous mode shooting. I found that in auto mode the camera was shooting ISO 6400 at 1/1600th of a frame to get the moon right, so I knew I was on the limits of the setup. The night of the event I set alarms to get the setup done, "you should be done by now", final checks and a 1 minute alarm. I got the focus done as well I could see on the live preview of the camera and waiting. I wasn't able to PA as it wasn't dark enough, so I knew tracking would have to be tuned a couple of times in the run up. As the 1 minute alarm sounded I had my finger on the trigger and stared intently at the seconds on the clock. At 22:11:14.5(ish) I pushed and held the button. 1.5s later I looked up at the moon and watched the station go by. Then I went back to see what I'd managed to capture. I saw that there were some white pixels in the image, so I captured another 60 images of the moon to stack. And here it is, the ISS right over the terminator. The ISS is totally over exposed, so there is something to improve for next time, but I'm quite happy for a first attempt, I was expecting to miss it completely. And because it appeared in all 6 shots, I put an animated gif together
  38. 11 points
    No big scope tonight as mount unavailable so inspired by Nik Szymaneks talk on Sunday I had a quick stab at imaging the moon with an Ha filter. 72ed / reducer / Ha filter / ZWO1600 , quick process on ps android.
  39. 11 points
    Well I collected a load of data last year and had to throw it all away because I couldn't get rid of some dust bunnies, so this year I was determined to get it right and hopefully have succeeded. The processing was so critical that I despaired of ever getting an image that I could be proud of, it really tested me to the limit. Link to more info: - https://www.astrobin.com/r4s23i/ Dates:May 27, 2020 , May 28, 2020 , May 29, 2020 , May 30, 2020 Frames: Chroma Blue 2" unmounted: 8x780" -20C bin 1x1 Chroma Green 2" unmounted: 8x600" -20C bin 1x1 Chroma Ha 3nm: 8x1200" -20C bin 1x1 Chroma Luminance 2" unmounted: 21x600" -20C bin 1x1 Chroma Red 2" unmounted: 8x696" -20C bin 1x1 Integration: 10.8 hours GSO/Altair RC 10" Truss, Moravian G2-8300 MkII, iOptron 120EC Mount, Chroma 2" LRGB & Ha Filters, Ultrastar Guide Camera Here's the bumf: - The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on spiral galaxy distanced 21 million light-years (six megaparsecs) away from Earth in the constellation Ursa Major. Discovered by Pierre Méchain on March 27, 1781, it was communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final entries. On February 28, 2006, NASA and the European Space Agency released a very detailed image of the Pinwheel Galaxy, which was the largest and most detailed image of a galaxy by Hubble Space Telescope at the time. The image was composed of 51 individual exposures, plus some extra ground-based photos. On August 24, 2011, a Type Ia supernova, SN 2011fe, was discovered in M101. Discovery Pierre Méchain, the discoverer of Messier 101, described it as a "nebula without star, very obscure and pretty large, 6' to 7' in diameter, between the left hand of Bootes and the tail of the great Bear. It is difficult to distinguish when one lits the [grating] wires." William Herschel noted in 1784 that "...in my 7, 10, and 20-feet [focal length] reflectors shewed a mottled kind of nebulosity, which I shall call resolvable; so that I expect my present telescope will, perhaps, render the stars visible of which I suppose them to be composed." Lord Rosse observed M101 in his 72-inch diameter Newtonian reflector during the second half of the 19th century. He was the first to make extensive note of the spiral structure and made several sketches. To observe the spiral structure in modern instruments requires a fairly large instrument, very dark skies, and a low power eyepiece.
  40. 11 points
    Hello everyone, this is my first post on the forum! I’m currently enjoying observing the moon with my Skywatcher Skyliner 200P. Clavius and the Straight Wall are nicely placed along the terminator this evening. The floor of Clavius is in shadow but sunlight is reflecting off the two craters within it. Worth taking a look if you have the chance! I have attached a picture I took with my phone. Hope you enjoy
  41. 11 points
    Got a couple of vids last night around 9.30pm but the seeing was pretty poor and only bothered processing this one. Found it hard to focus even with the red filter. My intended target was the lava dome to the SE of Beer crater but that was still deep in the darkness and contrast there was very low. Nevertheless is was still a good first light for my new ZWO filter wheel (EFW mini). I enjoyed just effortlessly flicking between filters and comparing the views for far too long! 8.75" Fullerscope with APM 2.7x Barlow, altair GPcam3 290m and red filter. 10k frames collected and 1k stacked. Cheers
  42. 11 points
    Well after the various trials and tribulations trying to get the M4 glob, here it is. The quality of the data in each LRGB channel was very variable with bloated stars from poor tracking and seeing, so it certainly doesn't stand up to pixel peeping. Nevertheless, it serves it's purpose of improving the one wide field image of this target that I had in my Messier collection. I may reprocess this as I think I pushed too hard with several of the steps, but otherwise I think I'm done with this target, which is a shame as from a more southerly latitude this would be a glorious object to view and/or image, appearing somewhat larger than M13.....
  43. 11 points
  44. 11 points
    A quick stack of 5 Ha 600s 1x1 subs...
  45. 10 points
    Hello Astronomers, This is a center crop of Sh2-308, AKA The Dolphin Head Nebula in the constellation "Canis Major". I was told that it is a waste of time to image this object with a DSLR. Apparently you need a cooled mono camera to get anything but I figured that my DSLR is cooled somewhat, modded and I have nothing to lose to try.... and IMHO the result is better than I was expecting it to be. This was imaged through Baader 7.5nm HAlpha & OIII narrowband filters using my full spectrum modded and cooled Canon 40D DSLR and the Bosma 80mm refractor at 500mm focal length. This photo consists of 46x1200s of HII, 35x1200s and 2x600s of OIII and 36x60s, 32x150s and 21x210s of RGB subs @ ISO1600 for a total exposure time of 30.5 hours. This object is very weak in HAlpha signal but very strong in OIII. The benefit of a color camera is that I captured two spectra lines in one exposure, I had OIII signal in the green channel while simultaneously captured HBeta in the blue channel in the stack. I assembled this image as HAlpha as Red, OIII as green and HBeta as blue. The weak HAlpha signal outlined some parts of the bubble (the front of the dolphins head) so even if the HAlpha was weak, it was not a waste of time as it added detail to the image. One thing that is different with capturing this image than my usual imaging procedure was that during my last imaging project, my USB port on my DSLR failed, meaning that I couldn't dither my subs, which would make a bit of a difference. Thank for looking, Clear Skies, MG
  46. 10 points
    Just a quick post to mark the superb seeing on the moon this evening. Plato craterlets, Vallis Alpes central rille, Catena Davy craterlet chain, it's all up there and steady at 300x - 400x with the 12 inch dob right now
  47. 10 points
    Last night I decided to have another go at M13. I have always been fascinated with globular clusters, but my images have always been kinda meh, bordering bad. Not this one. I'm happy about it. Just for comparison, here's one I took last year... And this one is from 2017...
  48. 10 points
    A quick process of a small area of The Butterfly nebula near Sadr that I have been imaging over the last two nights. Hopefully the moon won't ruin tonights attempt to finish off this target with some more OIII and SII.
  49. 10 points
    After a very nice session of lunar observing, described here: https://stargazerslounge.com/topic/355693-cracking-seeing-tonight/ I spent some time with my 12 inch dobsonian observing some of the brighter globular clusters and planetary nebulae. Nothing too challenging but nice, relaxing observing. Messier 13 in particular, was very spectacular with my 6mm Ethos eyepiece - the full sprawling extent of the cluster took up about 1/3rd of the field of view at 265x, The dark feature known as "the propeller" was very evident. Very similar to this drawing by Michael Vlasov: By the time I was thinking of packing up, Ophiuchus was in full view. Looking at the Sky & Telescope Pocket Sky Atlas reminded me that Barnard's Star, our closest stellar neighbour visible from the northern hemisphere, was well placed, so I decided to have a look at it. I've not observed Barnard's Star for some time. It is reasonably faint at magnitude 9.5 so a little care is needed to make sure that the correct star is being observed. With my 12 inch dob it was not hard to see tonight and it does have an orange (to my eye) tint to it. An up-to-date star chart is needed because, due to it's relatively close proximity, Barnard's Star has a large proper motion - just over 10 arc seconds per year. I found this "Astronomy Now" piece by Ade Ashford very helpful in addition to my Pocket Sky Atlas: https://astronomynow.com/2018/08/17/find-barnards-star-the-suns-closest-stellar-neighbour-visible-from-the-uk/ This is the 4th closest star to our solar system and the closest red dwarf apparently. It is only 1.9x larger than Jupiter and a lot smaller than our Sun: I took the liberty of waving, just in case anyone was observing us from there. Barnard's Star does have at least one known exo-planet which is thought to be about 2x-3x as massive as Earth Not a particularly hard challenge with a 12 inch scope but a nice way to round off a warm nights observing It looked nothing at all like this, of course
  50. 10 points
    Cooling for some lunar views
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