Paul Leyland

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  • in reply to: Back issues of BAA Handbook. #610714
    Paul Leyland
    Participant

    Already mailed my wants to David.

    I also have a few duplicates, so between us perhaps we can make a more complete collection for anyone else interested in building up a library.

    in reply to: Irish Astronomical Journal – free to a good home #610682
    Paul Leyland
    Participant

    Hmm, I can’t see how to direct message you from the forum interface. He is in Breaston, about 8 miles away from Nottingham.

    Please drop me a line at my firstname.surname (at) gmail dot com for his full address.

    Now arranged. Thanks James.

    Incidentally, how does one send a private message to another member? Anyone know?

    in reply to: Irish Astronomical Journal – free to a good home #610662
    Paul Leyland
    Participant

    Hmm, I can’t see how to direct message you from the forum interface. He is in Breaston, about 8 miles away from Nottingham.

    Please drop me a line at my firstname.surname (at) gmail dot com for his full address.

    in reply to: Redshift #610559
    Paul Leyland
    Participant

    There is no need to postulate expansion of space in order to explain redshifts greater than one, in fact you get z=1 for a velocity of just under 180,000 km/s which is quite modest and probably will be achieved by human artefacts[sic] sometime in the next few thousand years.

    I am not sure whether you consider tightly collimated clumps of electrons, positrons and protons as “human artifacts”. I do, because they do not occur naturally as far as I know, especially those of the positron variety.

    If you do include such things, we achieved such velocities many decades ago.

    in reply to: Irish Astronomical Journal – free to a good home #610557
    Paul Leyland
    Participant

    Tempted …

    My bother lives near by so collection would not be an issue for me.

    • This reply was modified 2 months, 2 weeks ago by Paul Leyland.
    in reply to: Elger; The Moon #610324
    Paul Leyland
    Participant

    If it had the maps, I suspect £1000.

    But it doesn’t, so my question remains.

    in reply to: New website feedback #610169
    Paul Leyland
    Participant

    And while I am on the subject: a preview-before-posting button would be nice too. Four edits in my earlier post could have been avoided …

    in reply to: New website feedback #610161
    Paul Leyland
    Participant

    We are told that BBCodes can be used to format our postings. I am one of those (very few?) weird people who have memorized a few such codes, such as [_i] [_/i] (underlines added for clarity) for italicizing intermediate text. I doubt that there are many other oddities like me. So, two questions:

    1) Would it be possible to provide a pointer to TFM for BBCodes for easy reference when posting and/or replying?
    2) Is it possible to provide buttons for pointy-clicky encoding of regions of text such as many other fora provide? See http://www.mersenneforum.org for an example where I post rather often if you want to see what I mean.

    • This reply was modified 3 months, 1 week ago by Paul Leyland. Reason: Edit tags
    • This reply was modified 3 months, 1 week ago by Paul Leyland.
    • This reply was modified 3 months, 1 week ago by Paul Leyland.
    • This reply was modified 3 months, 1 week ago by Paul Leyland.
    in reply to: Logging in to the new website #610160
    Paul Leyland
    Participant

    Thanks Andy.

    I have no issues at all with the auto-logout feature — I have been professionally employed in the IT security business for well over 30 years — but the other is a WIBNI which could well take time to implement but would also be valuable if it can be done.

    in reply to: Elger; The Moon #610159
    Paul Leyland
    Participant

    I may very well be interested. Guideline price?

    in reply to: Logging in to the new website #610135
    Paul Leyland
    Participant

    The site logs me out after a period of inactivity. That is mildly annoying but nothing more.

    What is annoying is when I am logged out when the Forum page is displayed. To contribute I have to re-authenticate (fair enough) but after doing so I am not returned to the previously displayed page.

    Can this be fixed?

    in reply to: ASTAP #610078
    Paul Leyland
    Participant

    I don’t (yet) use ASTAP but thanks for drawing it to my attention. I will take a look.

    Russ Laher’s Aperture Photometry Tool, APT, is my tool of choice. Written by a professional at the ZTF for professionals and amateurs alike it does a very good job very easily. It produces CSV format output which is easy to convert to a BAA-VSS spreadsheet. A script to do just that is available from me on request.

    APT is available from https://aperturephotometry.org/ and there’s a Wikipedia article at https://en.wikipedia.org/wiki/Aperture_Photometry_Tool

    A particularly nice feature of APT is that the apertures can be elliptical, so tracking errors can be tolerated better than with purely circular apertures.

    For plate solving I use a local installation of astrometry.net with the Gaia DR2 catalogue.

    in reply to: Mercury’s Sodium tail #610057
    Paul Leyland
    Participant

    As Comet Section director I like planets that look like comets…

    I like comets that look like planets 😉

    Most of the small junk out in the solar system like Caliban, Nereid, Quaoar and Makemake would be brilliant comets if they came close enough to us.

    • This reply was modified 3 months, 2 weeks ago by Paul Leyland. Reason: Fix [/quote] tag
    • This reply was modified 3 months, 2 weeks ago by Paul Leyland.
    in reply to: Very slow possible nova in Vela #610052
    Paul Leyland
    Participant

    Dec of -56 degrees is a bit far south even for La Palma. I will pass on this one.

    Paul Leyland
    Participant

    On Twitter Martin Lewis asked about this event. The thread is available at https://twitter.com/SkyInspector/status/1520183595167481856

    https://twitter.com/richard_e_cole/status/1520217320819507205 suggests that it may have been a fuel dump from Cosmos 2555 as the orbit tallies rather closely.

    in reply to: Theta Aurigae – A Double Star? #609962
    Paul Leyland
    Participant

    The nearest star, alpha Centauri, is 1.3 parsecs away and although it is a multiple system the separations are many AU and the orbital periods are much more than a decade.

    Thinking about it, if you are prepared to use a robotic telescope and/or travel to the southern hemisphere and are willing to relax your orbital period requirement to 80 years, alpha Cen is also a possibility.

    in reply to: Theta Aurigae – A Double Star? #609958
    Paul Leyland
    Participant

    Thank you, that is very helpful. Now take a little time to think about some elementary geometry.

    The definition of a parsec is the distance at which one astronomical unit subtends one second of arc. A parsec is about 3.2 light years, and Jupiter orbits the sun at a distance of 5AU in 12 years. Seen from a parsec away, Jupiter would be at most 5″ from the sun. A more massive object would orbit more quickly at the same distance, or be further away for the same period, ’tis true, but we’re talking order of magnitude estimates here.

    The nearest star, alpha Centauri, is 1.3 parsecs away and although it is a multiple system the separations are many AU and the orbital periods are much more than a decade.

    The only one which stands a chance of meeting your requirement is Sirius which is 2.7 parsecs away and where the companion is at most 11″ from the primary; the orbital period is about 50 years. A fair number of people have imaged Sirius B, myself included (see the gallery), but it is far from being an easy object.

    Good luck!

    If you want to measure stellar movements over a short period of time I would suggest that you start with stars of high proper motion. Barnard’s star is the easiest target and its movement can be measured within a week or two if you are careful. It moves around 11″ per annum, or 1″ per month. Careful astrometry should be good to around 0.3″ with amateur equipment. Again, see the gallery for my animated GIF which shows the movement from one summer to the next.

    Paul

    • This reply was modified 3 months, 2 weeks ago by Paul Leyland. Reason: Fix tyop
    • This reply was modified 3 months, 2 weeks ago by Paul Leyland.
    in reply to: New website feedback #609929
    Paul Leyland
    Participant

    Robin posted the above some hours ago. As is my usual habit I clicked on the “8 hours 43 minutes” link on the forum contents page which normally takes me to the last post in the thread so annotated.

    On this occasion it took me to the Reply-To: form, the one into which I am now typing. This behaviour was reproducible.

    My guess is that Robin’s post is the last one on the page and the javascript has a fence-post error which led it to create a new page.

    in reply to: Theta Aurigae – A Double Star? #609912
    Paul Leyland
    Participant

    What do you regard as a “short period”?
    What do you regard as “wide”?

    Hard to give specific advice without answers to those questions.

    in reply to: Asteroidal whine #609686
    Paul Leyland
    Participant

    Thanks Alan.

    At least in here in La Palma the temperature never falls below 5C, and that figure only exceptionally. I have experienced 7C on this visit, but that is unusual too and the lowest I have ever encountered. “Here” is Tacande at an altitude of 760m. Up on El Roque it falls well below zero every winter.

    I am also fortunate here in having a warm and lit control room, well-equipped with a kettle.

    Having spent many hours below freezing outside in the UK, with only a cat on occasion to keep my hands warm (another long story), I know well what you mean.

Viewing 20 posts - 21 through 40 (of 483 total)