SteveBz

Hi People, I have a shed with a very light lift-off Perspex roof and I'd like to automate this with rails. The shed is actually two sheds joined together, one with bikes and garden tools and one with a scope. I'm planning to rebuild the tool-sehd only and put a single roll-off roof spanning both sheds. The whole structure is 4m wide, although during the rebuild, I might expand the shed part by another metre making it 5m wide. The observing shed is about 1.5m wide. So the plan is that the whole roof will be motorised to slide by 1.5 m to expose the telescope etc. Can you please recommend a cost-effective rail for this? In particular the rails should slide sideways, but also hold the roof down in case of a storm, so I'm thinking a C-profile rail with rollers fitting inside the 'C' so that the roof wont lift off either. Thanks for your help. Kind regards, Steve.

I have one, but the driver for the PCDirect is just not as good as the driver for the EQDir.

Yes. It's a very small space, I don't want anything to move. I only ever image between about 23:30 HA and 03:00 HA - in a Westerly direction, which gives me about 3 hours on most objects, and that's OK. If I do e flip, it's likely to hit the shed walls. Really all I want is to unpark pointing Westerly, not Easterly. Tx. Steve.

Hi Fellow Astronomers, Last night was a beautiful night, 7 hours or more of M82, NGC4565 and M101. But every night I have to unplug my EQDIR and plug in my handset so that I can get the mount the correct side of the pier before booting up my software. I always boot in the West-facing direction, whereas my software boots in an East-facing direction. I plug in the Synscan handset to right matters, and then unplug to plug in EQDIR (KStars and INDI on a Raspberry Pi, since you ask). What I'd like to do is have them both plugged in together with an adapter. Do you think that's OK or will they clash with each other. Regards, Steve.

That would be hidden by my normal diffraction spikes!

I think it probably would, but as it means playing with hex-keys, I'm a bit reluctant. That's a good idea. So I think I'll probably get the 290 and do as you suggest. Kind regards, Steve.

So you are exactly right, I'd forgotten that. I have a Thin OAG (like the Orion one) with a 55mm distance, and I think it's a 9mm prism (or maybe 8mm). Are you still thinking the 290? Steve.

Hi Vlaiv, Your stars are very round. I guess that's the RC in action! Mine are distorted even with a coma corrector. My guide camera is screwed straight into the OAG. As close as it can. I don't see any vignetting, but I don't get so many stars either. I was binning x3 with the qhy. I think I'll go with the 290. It seems more sensitive. Kind regards Steve.

Hi Guys, I've been guiding with a QHY5L-iim/OAG setup for the last year or so. I can nearly always expect to find a guide star in any frame I GOTO, however there have been a few cases when that has not been true and my sequence has failed. Recently an unexpected storm drenched all my electronics including the QHY5L-iim, which doesn't appear to have recovered. So I now need to replace it. The question is, do I chose another QHY5L-iim, and maybe increase the exposure time for some frames from 1s to 3s, for instance, or should I choose a ZWO ASI290mm-s? It seems a bit more sensitive, although the chip seems a littler smaller. What are your thoughts? Thanks Steve.

Hi People, It was great to see so many unfamiliar faces at the talk on Friday. We had more people than in a long time. Thanks for coming. I've just uploaded the talk to YouTube, in case you missed it. Sadly I missed the first 2 slides. Several people have asked if he's published the slides anywhere and I've asked. I'll post here if so. (1) What you are sure is true - but isn't - Prof Stacy McGaugh - YouTube I hope that's good. Kind regards, Steve

Hi Fellow Astro-addicts, I hope you are all well. Clear nights have been few and far between. I am inviting you to a Zoom talk by Professor Stacy McGaugh from Case Western Reserve on 'Dark matter and gravity in the universe'. Prof McGaugh is a bit of a celebrity, he did that SPARC survey of 153 galaxies you'll remember about 3 years ago showing that the relationship showing that the rotation curves of galaxies and their luminosities were completely related and therefore the question is how dark matter might fit in, if at all. Zoom is downloadable free on your mobile phone, your laptop, your PC or Mac. Our Agenda for Friday 19th, is: 1 – Get people connected. The link is https://us02web.zoom.us/j/82510391783... (Meeting ID: 825 1039 1783, Passcode: 374052). I will start the session around 7.15 for a 7:30 start. 2 – Introduction and Astro News. 3 – Prof Stacy McGaugh from Case Western Reserve University talks about 'Dark matter and gravity in the universe'. 4 – Virtual break for virtual tea and coffee (or something stronger) 5 – Observatory update - exciting news. 6 – University connection (a call for hands) Gaia II data analysis with Instituto de Astronomía, Mexico City. 7 – Sky Diary Please let me know if you would like to do a trial connection beforehand. Hope to see you there. Regards, Steve.

I'll try this. Tx.

Hi Guys, I couldn't get the .msi dependency to install. Otherwise I think it would have run under Wine. Tx Steve

Hi Robin, Thanks for this. I found I needed to click the checkbox. Done. But I totally can't get ISIS to work! Tx Steve.

Hi People, I am trying to compare the three pieces of software to analyse astro-spectra. I've downloaded: - Visual Spec - RSpec - ISIS. VSpec seems amazingly unstable and counter-intuitive. ISIS seems stable and it looks as though it will do a lot, but the only current tutorial I can find seems to be for version 5 and the published software version is version 6. They don't look anything alike. It mentions a wizard, but I can't find one. RSpec seems more intuitive, but doesn't do very much and costs money. Also I'm on Linux, and although I can make them work, if they were bad on Windows, they're worse on Linux. What to do? I'm feeling a bit dispirited about it. Sorry for the low tone of this post. Regards Steve.

Hi Robin, Thanks for this. Here's an update. I wasn't sure which stars were which so I took a handful of stars from Auriga. All about 50 exposures, then stacked in Siril and finally, I stretched the spectrum in Gimp. Here's the result for 4 Aur: You can see three Balmer lines quite clearly here. Here is the graph from RSpec, which also shows them (I think I've truncated the O-O lines at 762nm). I haven't quite worked out to keep the scale between two spectra so I can just do the zero degrees line. Thanks Steve.

Hi People, I just wanted to ask for your feedback on this spectrum of Capella taken with a borrowed SA100. I've ditched the SW80 for a Bresser 114mm Newtonian with a focal length of 500mm which piggy-backs my main scope. It's much easier to focus. Sadly, the camera turns out to be a DSI III colour, not the mono, so there is some distortion because of the Bayer matrix. Here I took 50 images of Capella at 2 secs and stacked and cropped with Siril. The distance to the sensor is about 50 mm (I've used a 20mm extender). In the hour or so of clear skies last night I popped out to do a bit of spectroscopy. Here's the result: You can already see a strong line in the IR, which I take to be Oxygen. If I calibrate and analyse with RSpec, here is the result: I'm thinking about how to get a cheap mono camera, I'll have a look in the classifieds, but apart from that, have I got the lines right and what's the next step for me? Thanks very much. Steve.

Yes, and I didn't guide either. But If I switch back and forth between imaging and spectroscopy, I have to set up and align each time. I was trying to have two parallel scopes and be able to choose on the night whether to image or take spectra. If I have to switch over each time, then it takes half the evening (ie half the available viewing time) and we have so little time at the moment, it's a real heart-break to waste that time. Maybe I could find a cheap Newtonian like one of those little 76mm ones and mount it in place of the SW80 and still run parallel scopes. In fact I do have a 114mm scope of 500 mm that might not be too heavy. That's an F/5. I'll look into it.

You always give such thorough and great answers. This answer especially. So my plan of action should be: 1 - Revert to 50mm. 2 - Switch the scopes (sadly, if I do this, I have to decommission my Orion Thin OAG). 3 - Investigate the DSI III camera driver (there has indeed been quite a long discussion about it recently about NOT debayering the colour version, I wonder if they've got the 'not' in the wrong place). I can get rid of the debayering problem by binning, but that reduces the resolution of the image, however, it buys me time while I do the other actions. Thank you as always. Regards, Steve.

Hi Guys, Following on from our last conversation, the DIY spectrometer went totally wrong!! So I'm now testing a Star Analyser 100. Here are some results and I don't really feel I've got the best out of them. Could you guys comment, please? The set up is a SW80 with a DSI III pro - mono. Sensor has 1360 x1024 by 6.45 μm pixels. It also has some marks on the sensor. I set it up at both 30mm distance and 50 mm from SA100 to the sensor. These two are Bet-Cas and Del-Cas at 50 mm: Bet-Cas Del-Cas Del-Cas (RSpec binned) Potentially I worry that I am 1) out of focus, 2) Camera is too pixelated, 3) SW80 has too great a chromatic aberration, 4) the 50 mm distance to the sensor is too great, 5) maybe I need some flats or 6) All the above. I've been driving with the C8-N and imaging with the SW80. I suppose I could switch the cameras round and drive with the SW80 and image with the C8-N. That would deal with the chromatic aberration. Just before the clouds rolled in I took out the spacer and focused again. It's just a random piece of sky in Taurus at 30 mm from the sensor. I'd love to know what you think. Regards Steve.

I tried RSPEC. Do you guys agree with this?

So I got out last night to get some spectra of Bet-Cas. Here's the .jpg & .NEF (Nikon Raw) file. I can just about see some bands visually, but when I convert to .FIT and open in vspec, it's saturated. Not sure what's causing that. You can see that the right-hand side it quite well focused and the left-hand side goes into a fishtail as you said. Looking visually, so can see about three bands spaced about right in the blue end of the spectrum for H-Beta, H-Gamma and H-Delta, but I can't process that. The other thing is that DSS stacking doesn't seem to work when the stars are so out of focus because the FWHM is so poor. Your thoughts about what I should do next would be appreciated. (So to be clear, this is my DIY spectrum with $5 film off ebay - no pound sign on my keyboard) Kind regards Steve. FOCU_20210123_222253.NEF

Nice. It's already in a box. Mine isn't. I used this one: Mini DC Motor Speed Control Driver Board 3V-35V 5A PWM Controller / LED dimmer | eBay

Sorry, checked again. Typo. Yellow, Purple, Black, Black.