MercianDabbler

Pain in the posterior more like

Cheers. I did discover that the catalog file format is documented on the old Sourceforge Wiki for Stellarium. Documented... but very far from straightforward so I don't think there is much of a chance that someone could easily open the thing up and correct it.

I did that too. Much cheaper I used printer paper and then sprayed it with acrylic after cutting to keep the damp out. Obviously it's not strong but I wanted to see if it helped before committing to anything that was more effort or money. I used it once with my SP102. My experience was that the diffraction fringes were less evident than the ones in the 'how to' on the Interweb and so it was less easy to tell when they were properly aligned. I didn't notice any improvement in my end result. Since then I've gone back to manually focussing using the x10 enlargement on the camera screen. I think that with CA in action there is no ideal focus point, just 'least bad'

Thanks... kinda glad it's not just me. I'm not sure if anything can be done about it. I believe that the star catalogues originate elsewhere (and from more than one place) but how to track down the source of this incorrect star and get it corrected is not clear to me. There is no identifier or name for the star that might give a clue.

Welcome to SGL and hope you find this a rewarding hobby.

It wasn't exactly tropical on top of Exmoor in October. Strangely enough Dartmoor is one of the few places where wild camping is allowed without asking the landowner first... not that a camper van in a car park constitutes wild camping but hey ho. I suspect the camper van people were not disturbed by the relevant authority.

Thanks for that. I was quite surpised that the framing worked out pretty well. I did check the preview on the camera screen but it's pretty small so the framing is probably more luck than judgement. Probably couldn't do it again if I tried

Glad to see that you've bought yourself a scope and it sounds like you've had a good time of it in Devon and did well with the weather. I sympathise on the feeling of vulnerability when out and about on your own with the car and telescope. Been there, done that. I don't have any great answers I'm afraid. Out of interest, did you come across many camper vans parked up overnight on the moor? I was in Exmoor last October (with scopes) and just about every car park on road across the high moor had a camper van in it with lights on. I do Dartmoor a lot but for some reason have never taken the scope with me... maybe because it's usually summer and too daylight. Must try harder.

Worth checking this... 1. Go into settings (F2) and then choose the 'Extras' tab. The middle section is 'Show additional buttons'. Switch on 'Nebula Background' (off by default). Close the settings. 2. Now you should see an extra button on the ribbon at the bottom of the main view to the right of 'planet labels'. This turns the background images on or off. Make sure they are turned on. The background images should be on by default so this may not be your issue but there is no harm in checking. The 'Extras' settings panel also has the option to switch on the 'flip' buttons. I find it quite handy to be able to switch the main view to replicate the orientation I see through the scope.

@John I looked at your screenshot again after posting my previous message. I think you may have the mag 7.55 star too but it is probably luck whether Stellarium shows the galaxy or the star description when you click there. I have now disabled the magnitude limits in mine so that all of the galaxy labels appear. Here is a view with background images ON and stars OFF (Sky and Viewing Options Window). The second 'eye' shows as an oval symbol. The same with stars ON - now the same galaxy has a white circular star splodge over it. To me the second 'eye' looks white and circular on your screen shot too.

Thanks for checking. Both 'eyes' galaxies are there on mine if I zoom in far enough, with 4435 right next to the spurious star. Well odd. I can only guess that there is something wrong in one of the data files but pinning it down seems like it would be a lot of effort. I'll try a complete wipe and a fresh install and see if that makes it go away.

This one has been throwing my star hopping off for several days. I could not find this star in the EP and assumed I must be doing something wrong. It finally occurred to me to look more carefully at some photos of the region and it seems that there is no mag 7.55 star in that position. The web version of Stellarium doesn't show it so clearly 'the truth is out there'. I've tried downloading the latest desktop version (0.21.0) but the star is still there. Do other folks see the same thing and is there any way to get a corrected star catalog?

Sounds like a great night. I must get out more myself but it will probably wait until after the summer now.

I like my Rigel finder. I used to find myself sighting along the tube on many occasions before I had it so it's probably not surprising that I like it. I now have the Rigel and the ST80 with a 26mm EP and have found this a good combo. At the moment I'm using a 45 degree prism so the ST80 doesn't flip the image. I don't know how I ever managed with the bundled finder scope back in the day. Probably as good as most bundled finders but a bit of a Chocolate Teapot really.

Last night was clear too so I decided that sleep was overrated and went out again. The plan was to clear up a few loose ends from Wednesday. The moon and clouds should guarantee that this was the last evening on this mission for the month. First job was to check the ST80 alignment by pointing at Spica again. This time I found I needed 10 thou of shim to point the ST80 slightly further left so clearly the alignment does not stay put... even if I leave the two scopes clamped together between sessions. It's still pretty good though and I'm not motivated to spend money on guide scope rings. It wasn't yet fully dark but the first target was M104 because I'd missed out on it during the previous evening. This was a not too difficult star hop from Spica. It just about showed up in the 15mm SLV and was better in the 9mm DeLite. I could not suspect the alignment on this occasion but the incomplete darkness probably did not help. Next job was to find rho Vir again as before and then head down to M49 which I had only just spotted in Stellarium as a viable target. This was a straightforward hop and not difficult to spot in the 15mm SLV. I'd also read of a nearby Supernova in UGC7513 on here. This was a very long shot but I armed myself with some Stellarium screenshots to see if I could find it. I couldn't do the star hop with any confidence - on this occasion there were just too many stars of a similar brightness and I kept losing my way. Time was limited so after a couple of tries I abandoned the attempt and moved on. The next itch to scratch was M86 (again!). I'd copied the photo from the previous night onto the tablet in various versions, flipped and unflipped and with a couple of variations of brightness reduction. I went back to the triangle of mag 8ish stars near to M87 and up from there. Maybe the conditions were worse but I could not see much that I could really hang any navigation on, new photos or otherwise. Once again the 7.55 mag star shown by Stellarium was not obvious through my EP. Checking again today it's also not obvious on my photo, nor is it obvious on other photos. Is it a mistake in Stellarium maybe? Anyway... another attempt at M86 and another failure to find it in the EP. The final task for the night was to attach the DSLR and grab more frames of M104 and see if it would improve the quality of my previous photo. I'd told myself to swap sides on the SP mount before starting - this would gain me a little more distance to the left of the nearby tree. Naturally I forgot when the time came. I got about 60 or so more 20 second light frames (I lost count) before M104 was definitely in the tree around midnight but I haven't checked them yet - the later ones may have been in the emerging outer foliage although the preview on the camera was still showing what looked like good images. At various points through the session I checked the 4 stars in the square of Ursa Minor by naked eye as recommended by @John. The best I could do was 2 stars with a suspicion of the third on one occasion so by John's test the transparency was not good. I'll use this test again to see if some evenings are better but I'm not sure that Ursa Minor is particularly well defined on any evening under the LP in my garden. Tonight I plan to remedy some of my sleep deficit

Cheers. I've only ever looked at one star in Ursa Minor TBH so must take more interest.

Is there a good way to judge transparency? I generally think that it's bad all of the time so that can't be right... probably light pollution.

Nice report. I usually overstay past my intended bedtime at the moment so well done for writing a report on here before turning in for the night. I hadn't realised that Lyra was visible at the moment but will probably wait a while before heading over there - it is pretty favourable later in the year.

I've now had chance to get the pics off the camera and mess with them a bit. A mosaic of two frames, each with three 20 second subs at ISO 12800, 5 darks, no flats. It's horribly noisy and won't win any AP prizes but at least I can see M86 and a bunch of other stuff via the DSLR. I may have seen M86 at the eyepiece too but I could not tell which 'thing' was M86.

I'm glad to see that other folks have been gettng plenty of cloud free time. I seem to have been less lucky with the clouds but have managed some further observing. While there are still opportunities to see the Virgo galaxies I wanted to improve my navigation so that I could be more certain that any failures to see something was down to the capacity of my equipment and the sky conditions rather than just my failure to find the right spot in the sky. Having done some further Googling I found that it is possible to toggle the galaxy photos off in Stellarium. This needs a manual edit on the config file (C:\Users\andy\AppData\Roaming\Stellarium\config.ini on my Windows 10 system) to set flag_show_nebulae_background_button to true. This shows an extra button on the toolbar allowing the images to be toggled on and off. While there I also turned on flag_show_flip_buttons which allows the view to be flipped when not in ocular view. In the Stellarium app I also set the limiting magnitude for DSOs to be 10... I certainly cant see anything over 10 in the SP102 and things over 9 are challenging. I'd also done a bit of a tune up on the ST80 focusser over the weekend. Having checked some YouTube videos I adjusted the two small Allen screws on top of the focusser and found a point where it wasnt wobbling and also wasnt too stiff. Sunday 11th had a good forecast but saw a late start due to cloud. The Virgo galaxies were the main item on the agenda. It's not really worth going into detail because the same targets (and more) were visited with more time available on Wednesday night with broadly similar results. Monday night was predicted to be clear by Clear Outside but the prediction worsened as the day went on. I waited until 9:30 before making a decision. There were a few small clouds around but looking to the North West I could see plenty more and predicted that they would roll in before I could get the SP102 set up. Instead I pulled out a folding chair and the 10x50s to have a crack at M51 and M101. I started at Mizar and a Starlink satellite streaked across the view. A few seconds after that... another one. I kept watching and eventually counted 45 or the little blighters on parallel tracks close to Mizar. Once that distraction had finished the cloud had worsened. I swung over to Leo and found another satellite heading from there towards Ursa Major. Soon after that had disappeared into cloud I saw a really bright one without the binoculars, again traversing Ursa Major, no doubt catching the sun because it suddenly appeared and then vanished again after covering less than the width of the main constellation. By now the clouds had completely won the day and the reflected LP made it almost like a full moon so I gave up and went indoors for a beer. Tuesday night clouded in during the early evening and there was never any prospect of any observing time. Wednesday night (14th April) was cloud free and predicted to remain so. I set up early, just after checking the classifieds on SGL and signing up for a used Celestron diagonal from @F15Rules It wasnt properly dark when I was up and running but I spotted Orion peeping between my house and next door so decided to have a final visit before it vanishes. It wasn't ideal - to start with I could not find M42 because it was still just behind next door but after a few minutes it came into view. I could make out 3 stars in the trapezium and intermittently four and also discern some of the nebulosity. Hardly a spectacular visit but nice to see it again. It still wasn't properly dark so while the scope was pointing that way I decided to visit M35 in Gemini. My first attempt was to star hop from Mars. Mars itself was pretty unspectacular and I was struggling to get to grips with the surrounding stars so instead I started from Alhena and managed a fairly straightforward star hop from there. Next I needed to re-check the alignment between the ST80 and SP102. I swung around to Spica in preparation for the main course. Surprisingly I found that the best alignment was when I removed all of the shims from the ADM clamps. Maybe my focusser tune up has given me perfect alignment or more likely it's just not completely repeatable. After the official start of full darkness I moved on to the galaxies. I started at Vindemiatrix and then hopped to the very recognisable 4 star group centered on rho Vir. From there I went NE to a 'T' shaped arrangement of stars which became the base for the remainder of the evening. Near the westward tip of the 'T' is M58. This seemed trickier than my previous attempt but eventually I picked it up in the 9mm DeLite having failed to do more than suspect it in the 15mm SLV. I tried to hop over to M60. I was confident that I was in the right spot but no joy so I moved on. Back again to 'T' and then up to M89. I did not have much difficulty spotting this one (Sunday had been the same). From there it was a more tricky hop to M90. Unlike Sunday I was sure that I was in the right place. Like Sunday I could not spot M90. Back again to 'T' and up to M87. My third visit this month and an easy spot. From there I was after M86 which had been the first Virgo galaxy that I'd tried unsuccessfully. There are no obvious stars to help with aiming and I could not even positively identify the Mag 7.5 star that Stellarium shows to the left of it (or right in the SP102) There were plenty of faint objects visible, some of which are probably galactic nuclei and some of them stars but I really could not get my bearings even after several attempts and going back to sit in the chair and study my screen shots on the tablet more closely. In the end I hooked up the DSLR to the scope, went back to rho for focus and then resorted to some ISO 12800 photos so that I could try to get my bearings next day. I haven't yet checked them. I had planned to finish with M104 but I had left it too late and it had gone behind a tree. Apart from that minor disappointment it was a most enjoyable session and I was packed up just before 1AM... plenty of sleep time before by 6AM alarm... not. I've now downloaded more stars into Stellarium and am trying to tune the limiting mag to what I can see. At the moment 11 to 12 seems like the ballpark.

Nice, better than my effort but you have a lot more exposure time. Looks upside down though

Hmm... my purchase is not going so well. It turns out that RVO don't actually have the Baader diagonal in stock unless I want the one without the attachments for the scope and eyepiece. I've had a reply from a retailer to my query about the Altair one but theirs are all sealed so they can't answer my question about the constriction/step. Looking again at photos of the Altair one it starts to look a lot like the Stella Mira/Skywatcher and William Optics ones... I get the feeling they are all variations on a theme with different branding on the triangular side panel. Maybe I'm wrong but just now I'm feeling that I'm not going to rush out and buy the Altair one. Mulling the problem over I started wondering if I could keep the crack closed by putting a toolmakers clamp around the housing. I think the body is a bit too wide for my clamps so instead I spent some time in the shed this evening making something that works on a similar principle but is made to measure. It's made from whatever bits of steel came to hand and isn't pretty but it should prevent the crack (and therefore the threads) opening up and ensure that the barrel stays put. Hopefully astro gear will become less like hen's teeth over the summer as lockdown eases and darkness is in short supply.

Thanks. That was one of the articles that I read. At F10 it seems like a prism has advantages in terms of lack of scatter. There is usually a tradeoff in all things but with diagonals the advantage for mirrors seems to be on fast scopes... which mine isn't. Tried that. My neck isn't that flexible.

Having read a bit more elsewhere it seems that a mirror offers little advantage on an F10 refractor and that prisms were preferred in the days when more people had long refractors. A mirror would be better on my ST80 but that's a secondary consideration. The Tak Prism diagonal is out of stock at FLO (not sure if it was when I first looked) so that's not an option now. Perusing RVO I found the Baader one that is ready to use without buying extra bits... https://www.rothervalleyoptics.co.uk/baader-prism-diagonal-t-2-90-with-focusing-eyepiece-holder-and-125-nosepiece.html The twist focusser might come in handy too. I hadn't really settled on a budget but this is probably fairly near to the mark. Hopefully that will buy me a decent quality diagonal without causing too many raised eyebrows from elsewhere in the household. I haven't made a final decision yet. I've also sent a query to Altair regarding the constriction question. I divorced Amazon some time back BTW after they signed me up for a 'free' Prime trial a second time against my wishes. They won't be doing it again.

Thanks John. I confess that I've never thought of a diagonal as something that can be adaptable or not. I get that there are different ways to grip the eyepiece nowadays but other than that one end goes in the focusser and the other end has an eyepiece inserted. Am I missing something? I guess that I do have a mix of EPs some of which have an undercut and others which don't. TBH I've never had a big issue with the old school approach - plain barrel on the EP and a thumb screw on the holder. My eyepieces are there to be used, not to be collectables but I don't rule out 'non marking' alternative holding approaches. Do those Baader ones need one to buy extra bits to connect to the scope and the EP? Sorry but reduced aperture is a no-no for me - it just seems like a backwards step even from my 30 year old diagonal.