Dr Paul Leyland

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  • in reply to: Comet C/2023 A3 visible in STEREO HI images #625848
    Dr Paul Leyland
    Participant

    Torrential rain this evening for me on La Palma

    Torrential rain and high winds for me that evening brought down the box of electronics on the microwave dish providing internet connectivity. Last night a friend discovered it lying in a puddle of water. Verimax have already fixed things, which is excellent service by a ISP, given that they only learned about the issue less than 6 hours ago.

    Relevance to comets? Kevin Hills is an avid observer and his robotic observatory is on my site, sharing the internet link with me.

    Now fixed. Impressive service from Verimax — under 4 hours from notification to a working connection.

    • This reply was modified 1 month ago by Dr Paul Leyland. Reason: Add final para
    in reply to: Comet C/2023 A3 visible in STEREO HI images #625752
    Dr Paul Leyland
    Participant

    Looks like I got out just in time! I flew back to the UK on Thursday.

    To be fair, La Palma badly needs some rain.

    in reply to: Equipment advice #625592
    Dr Paul Leyland
    Participant

    I am very seriously considering buying a Seestar S50.

    Very impressive results have come out over the last year. Not only “pretty pictures” but also hard science. As far as I can tell, they can do precision photometry (my principal interest) down to at least 13th magnitude.

    The only thing holding me back is a rumour that at 80mm version may be released Real Soon Now.

    in reply to: Congratulations to Dr Andrew Wilson #625591
    Dr Paul Leyland
    Participant

    When on holiday a GP I know tells people they’re a vet.

    Two things:

    1) a friend of mine fell off his bicycle outside a vet’s practice. He was given excellent first aid.
    2) Vets need to know at least something about almost everything medical concerning warm-blooded animals. They are generalists par excellence. To be honest, I would rather be treated for relatively minor injuries by a vet than by a brain surgeon or gynaecologist.

    in reply to: Congratulations to Dr Andrew Wilson #625359
    Dr Paul Leyland
    Participant

    Congratulations on being doctored!

    in reply to: Rev T.E.Espin’s Calver telescope :action needed #625118
    Dr Paul Leyland
    Participant

    I’m working on it, at least in part through SGL. I recently pointed out the contrast with Cambridge University, where the 160 year old Thorrowgood and 191 year old Northumberland telescopes are still in frequent use.

    In the end I suspect that the Golden Rule will apply. They who have the gold make the rules. I would certainly contribute some of my (virtual) gold to a restoration effort but I doubt that I could fund it all myself. Anyone here willing to step up as treasurer of a charitable trust?

    Paul

    in reply to: UZ Boo #624533
    Dr Paul Leyland
    Participant

    V= 16.27 +/- 0.02 at JD2460547.3847 ~= 20240824-21:13Z

    in reply to: Books for sale #624456
    Dr Paul Leyland
    Participant

    Tempted …

    in reply to: UZ Boo #624350
    Dr Paul Leyland
    Participant

    Good to see this coverage of UZ Boo and especially to see the appearance of SH’s. Hopefully these will grow.
    The sky here last evening was dreadful: I could only see Vega, Altair and a very coppery Moon.

    Nothing from me tonight because of the strong calima. Vega and Arcturus are obvious, Deneb and Altair with some difficulty. The moon is rising. Na light pollution from El Paso / Los LLanos about 2-5km away is visible, as is that from Santa Cruz on the other side of the island with a 1500m high ridge between us. Remember that La Palma has strict regulations against emitting light upwards and they are obeyed by and large, especially municipal street lighting.

    One of the worst nights I’ve seen in a long time, and I haven’t even mentioned the thin patchy cloud.

    in reply to: UZ Boo #624305
    Dr Paul Leyland
    Participant

    Although UZ Boo is still well placed in the sky from La Palma the sky itself has been appalling and it was not worth opening the observatory between 08-09 and 08-13 inclusive. Thick Saharan dust and high winds which create turbulence and bad seeing. Even last night A 15-pixel (8.75″) radius aperture was needed to include the bloated stars and the moonlit dust made the sky background so high that a 10 minute exposure was used to get adequate SNR. Such a time would generally let me get useful results for a target fainter than V=15.

    Anyway, UZ Boo was measured at V=12.35 on 2024-08-08 and 12.75 on 2024-08-14.

    in reply to: Satellite proliferation #624281
    Dr Paul Leyland
    Participant

    Yes and no, IMO.

    At the moment, and conditions may change, the “pretty picture” brigade have a readily simple mechanism to cope. They either discard subs impacted by satellites or they use (for example) sigma-rejection to discard the affected areas of their subs.

    The spectroscopists and (especially) photometrists are a little more constrained. If the satellite goes over (or too close to) the target all they can do is throw away that data. For photometrists,if the satellite goes over (or too close to) a comparison it is necessary to remove that one from the ensemble for that sub. A real PITA, admittedly, but hardly crippling if there are a good number of other comparisons in the ensemble. The major problem, IMO, is teaching the pipeline to reject those occurrences without human assistance.

    in reply to: UZ Boo #624220
    Dr Paul Leyland
    Participant

    Gary: by “keep going” do you mean time series in a single night (like what I am currently doing for ARPS asteroidal rotational light curves) or mean making one or a few measurements per night for as long as possible?

    I am hoping the latter.

    in reply to: UZ Boo #624218
    Dr Paul Leyland
    Participant

    Still rather easy here in the deep south.

    Now taking images but it looks around V=12.3. Precise measurements will be sent to the database when the data is in.

    in reply to: Seestar Objective Prism Spectroscopy #624008
    Dr Paul Leyland
    Participant

    Robin: was that with a glass prism? Glass is dense. There are much lighter transparent materials out there. Diamond may be ideal. Shame about the cost!

    The printed holder may also be thinned out perhaps.

    in reply to: Wil Tirion, 1943–2024 #623844
    Dr Paul Leyland
    Participant

    Will Tirion also drew a set of star charts specifically for the BAA, which we published in the 1980s. I covered mine in adhesive plastic and hung them up in my observatory – where they still are (well actually transferred to the warm room now, and rather yellowed). I’m thinking that due to this connection with the BAA, at least, the BAA should officially mark his passing, probably in the Journal.

    David: strongly agree.

    in reply to: Meade ceases operations #623797
    Dr Paul Leyland
    Participant

    Being the owner of a Meade Schmidt-Newtonian I am almost, but not quite, concerned about its future well being. I suspect that parts and technical knowledge will still be available for the rest of my lifetime.

    in reply to: Forum post editing problem #623776
    Dr Paul Leyland
    Participant

    Thanks Andy!

    in reply to: A General Relativity Question #623731
    Dr Paul Leyland
    Participant

    I strongly recommend Gravitation, aka MTW, for a comprehensive and relatively (pun intended) accessible course in classical geometrodynamics, despite it being wrotten 50 years ago.

    That said, I can’t answer your question off the top of my head. Let me think about it and/or consult MTW.

    in reply to: Pixel Value and Exposure #623730
    Dr Paul Leyland
    Participant

    Ah, I did indeed misunderstand.

    Nonetheless, I was unable to edit my post after 2s and before 10h after posting. Perhaps, through UBD, I didn’t understand what the incantation should be.

    Thanks.

    in reply to: Pixel Value and Exposure #623727
    Dr Paul Leyland
    Participant

    Thanks for the explanation.

    Is there a good reason why the expiry time is so ludicrously small? Other fora I frequent generally allow somewhere between five minutes and an hour. Long enough to spot speeling misteaks or to add an extra sentence of explanation, but not so long that it seriously distorts any historical perspective.

Viewing 20 posts - 21 through 40 (of 742 total)