Dr Paul Leyland

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  • in reply to: Finderscope Webcam #584258
    Dr Paul Leyland
    Participant

    Thanks, but I already have it myself. Anyway, the Pi has a fully functional C compiler and Perl interpreter which are my languages of choice and how I implement such code on all my other Linux boxen..

    On further thought, I also have the Pi IR-enabled camera so no need for a web cam, USB connection, fancy interfacing software, etc.

    in reply to: Finderscope Webcam #584256
    Dr Paul Leyland
    Participant

    Now wondering how much extra it would cost to go the whole hog and put a plate solver into the system. A Pi with a 32G SSD would have easily enough power to run it. Use a phone as a display and controller over wifi. Optics are 50mm refractor and web cam on a standard finder bracket, to which the Pi would also be attached. A pity a USB cable would still be needed but a rechargeable battery could presumably be attached to the mount somewhere, even on a Dob.

    Major development cost would be writing software.

    Hmm. I have a Pi-3 over in La Palma. Might have a play when I return there.

    in reply to: Finderscope Webcam #584230
    Dr Paul Leyland
    Participant

    We did consider using Uranometria as a guide to star hopping, but I’m afraid the Bodleian didn’t seem keen to lend out their copy ….

    How faint do you need to go? Freely available charts reach mag 7.  Here is one of Orion, for example, and another around the NCP.

    in reply to: mount vibrations #584214
    Dr Paul Leyland
    Participant

    Something which worked well for us back in the day was to get a 10 foot long cast iron pipe, complete with drilled flanges at each end, from a scrap yard. It was painted inside and out with bituminous paint. A hole of suitable dimensions was dug so that a plug of concrete 3 feet thick and three in diameter could hold the bottom of the pipe, which was buried to slightly more than half its length. The inside of the pipe was then filled with sand. The top flange was ideal for attaching an equatorial head.

    The fundamental vibration mode and small harmonics were heavily damped by the concrete and through being clamped with back-filled sand. The internal sand quenched high frequency vibrations very effectively.

    It was possible to have one person placing fingertips very gently on one side of the pipe while another hit it as hard as possible with a length of 2×3 on the opposite side and still feel no vibrations.

    in reply to: Increased Solar Activity #584122
    Dr Paul Leyland
    Participant

    I saw a weather report yesterday. Unfortunately I failed to save the URL. It would be nice to have a more authoritative source than that given below but …

    https://www.express.co.uk/news/science/1427137/space-weather-forecast-solar-storm-aurora-evg

    in reply to: Fontana Translation Peter Fay Sally Beaumont #584107
    Dr Paul Leyland
    Participant

    Does this help? Being an Oxford man I went to the Bod, which led me to this:

    https://discover.libraryhub.jisc.ac.uk/search?author=Fontana,%20Francesco&title=New%20observations%20of%20heavenly%20%26%20earthly%20objects&title=&isn=&isn=

    An interlibrary loan may be possible. Worth asking, anyway.

    Dr Paul Leyland
    Participant

    Thanks.

    Yes, very easily visible. I’ve imaged galaxies in that sort of range.

    Dr Paul Leyland
    Participant

    Hmm, I wonder if it is akin to SN1987A? I doubt that the LMC would be readily visible at that distance.

    in reply to: Important research papers published #584026
    Dr Paul Leyland
    Participant
    Detection of Rotational Variability in Floofy Objects at Optical Wavelength https://arxiv.org/abs/2103.16636
    in reply to: observer’s images – plate solving error #584022
    Dr Paul Leyland
    Participant

    My offer of assistance from a few months back still stands.

    Paul

    in reply to: Aberrations in astronomy #584009
    Dr Paul Leyland
    Participant

    The first Dobsonian I had showed serious spherical aberration.

    Worked just fine as a light bucket, which I what I wanted it for.

    in reply to: 2021 DW #583920
    Dr Paul Leyland
    Participant

    Yes!

    Please try it if you can; you only have a few more days of it being bright enough.

    Really regretting not being in La Palma right now.

    in reply to: 2021 DW #583918
    Dr Paul Leyland
    Participant

    Further: note that the proposed rotation period of only 25 seconds implies that exposures of only a few seconds will be needed to get a good light curve. In practice, this suggests only 0.7m-class or larger telescopes will be able to do this successfully, likely implying the use of robotic telescopes.

    Getting colour indices, on the other hand, should be somewhat easier as exposures >25s will average out the rotational behaviour. This could be a productive use of personal telescopes fitted with two or more standard photometric filters.

    My thanks to Richard Miles and Tomasz Kwiatkowski for the further information.

    in reply to: Camera won’t connect #583911
    Dr Paul Leyland
    Participant

    And vice versa, in my experience. Over-long USB cables can give connection problems which are sometimes solved by using a powered hub.

    Try it both ways, in other words.

    in reply to: Photoacoustic effect #583880
    Dr Paul Leyland
    Participant

    I have absolutely no idea whether this might be an explanation, but I believe that aurorae produce radio waves which can be picked up by radio receivers.

    There have been documented cases of unexpected diodes (akin to the good old cat’s whisker) producing audio outputs from AM radio transmissions. A few cases involved mercury amalgam dental fillings, for example.

    I wonder whether this may be relevant.

    in reply to: PHD Study Opportunity #583850
    Dr Paul Leyland
    Participant

    I’m also tempted, despite my age, but my itinerant lifestyle may make things difficult.

    in reply to: iTelescope #583816
    Dr Paul Leyland
    Participant

    Have you also tried asking on CN and SGL?

    I will ask my Twitter followers.

    in reply to: CMOS for Photometry #583815
    Dr Paul Leyland
    Participant

    You could always just suck it and see. It shouldn’t take more than one night to take dozens of exposures of a relatively bright star at a variety of settings. Then process them and see what works best for your equipment.

    in reply to: What mini/micro PC? #583783
    Dr Paul Leyland
    Participant

    You make a good point, but up here in the sub-arctic the night time is very often at or below fridge temperature (~5C). When it doesn’t it often never gets dark at night anyway.

    At the opposite extreme, a good calima in La Palma can result in the air temperature being higher than 20C all night and even a good two-stage Peltier cooler can’t get a camera much below -15C.  Been there, done that.

    in reply to: What mini/micro PC? #583757
    Dr Paul Leyland
    Participant

    I have an Odroid running Ubuntu and Kstars/EKOS as a proposed replacement TCS. I have been quite unable to find a driver for the dome controller (a Vellman board) and there are still teething problems with the mount (a FS2 controller). All the SX kit works perfectly; not yet tried the focuser. It will be months before I can return to La Palma and try to resolve these issues. 8-(

    A Celestron NEXIMAGE 5 purchased via the BAA forum also fails to work under the local Ubuntu installation but I have found a package which claims to contain a driver for the camera.

    Other people with more main-stream equipment have no significant problems with Linux-based controllers.

Viewing 20 posts - 481 through 500 (of 810 total)