Dawson

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Viewing 20 posts - 21 through 40 (of 227 total)
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  • in reply to: Lunt driving me mad #629836
    Dawson
    Participant

    This is from today. The gradient in brightness is not a natural feature, it is artefact.

    in reply to: Lunt driving me mad #629834
    Dawson
    Participant

    I’ve not. Invariably this scope is set up outside so tracking is usually awful. I just feel there is somethign fundamentally wrong and I’d like to resolve it one way or another.

    Thanks.

    James

    in reply to: Local Society newsletters / journals #629797
    Dawson
    Participant

    Thanks Bill.

    in reply to: Sparsholt Winchester Weekend 2025 #629486
    Dawson
    Participant

    Yes an absolutely brilliant weekend. I was exhausted when I got home last night. I’ve come away with lots of ideas of things to do to improve my own observing techniques and new things to have a go at. Also great to speak to people who I only ever encounter online. The BAA at its finest. Thanks for all who organised and ran the show, especially Tony, Ann and Alan, but also the helpers on the BAA stand, registration desk etc. Brilliant.

    in reply to: Disadvantages of cooled camera #629451
    Dawson
    Participant

    Thanks Gary.

    in reply to: New SWAN comet in the morning sky #629446
    Dawson
    Participant

    I got up early yesterday (9.4.25) before work and managed to get the attached. Pretty disappointing, and the tail very faint compared to other observations I’d seen online. Askkar 120 with 0.8x reducer and Canon 6D, this is about 12 minutes in total of the best subs captured between 03:17 (UT) and 03:54 (UT); there were lots of bad subs. 30 seconds each, ISO 400. Desaturated and inverted to allow me to see the tail.

    Attachments:
    in reply to: Sampling when imaging #629398
    Dawson
    Participant

    Well spotted with the relative QE. I’d missed that.

    James

    in reply to: Disadvantages of cooled camera #629395
    Dawson
    Participant

    Thanks both. Helpful comments and insight.

    James

    in reply to: Sampling when imaging #629370
    Dawson
    Participant

    Martin, thanks for that link. It is interesting, depending where you look, the transmission data varies… Surely the colour IMX585 should have a near identical transmission profile whatever camera it is in? Here are three plots, one from your link, one from the ZWO website (https://www.zwoastro.com/product/asi585mc-mm-pro/) and one from the PlayerOne website (https://player-one-astronomy.com/product/uranus-c-usb3-0-color-camera-imx585/).

    James

    Attachments:
    in reply to: Sampling when imaging #629355
    Dawson
    Participant

    Martin, thank you.

    Yes, poor Chris Hooker has been helping me, dragging me along really as I’m not that bright when it comes to solar physics, magnetospheres, energy states, wavelengths etc…! But good fun for me anyway. I’ve just seen there is a 585 mono camera which appears to have a QE of just under 90% at 589nm. I may have to do some overtime. The binning is an interesting idea I’d not thought of.

    Regards

    James

    in reply to: Sampling when imaging #629338
    Dawson
    Participant

    Thanks David.

    James

    in reply to: Sampling when imaging #629303
    Dawson
    Participant

    Thanks David. Do you know when Martin gave this talk?

    Regards

    James

    in reply to: Partial solar eclipse – 2025 March 29 #629228
    Dawson
    Participant

    We are going to try and live stream from Nottingham too in white light, and Ha if the clouds permit. Live stream should go live just before 10am.

    https://youtube.com/@nottinghamastronomicalsociety?si=niCKwEgSv8w_qnWi

    James Dawson
    Nottingham Astronomical Society

    in reply to: Bright propellant dump visible over the UK tonight #629102
    Dawson
    Participant

    We got it in Nottingham too on the all sky camera and both meteor cameras:

    https://youtu.be/Pm4pqW7jNaY?si=zqSEIPv6M1a9R0kZ

    in reply to: DwarfLab smart telescopes #628863
    Dawson
    Participant

    I’ve just seen your image and am REALLY impressed. Looking forward to seeing what else you achieve with it. Congrats too.

    Dawson
    Participant

    Looking forward to it. I am bringing a load of second-hand books to try and sell on behalf of the Society for the History of Astronomy.

    See you in a few weeks.

    James

    in reply to: Impurities on the ccd sensor? #628609
    Dawson
    Participant

    It is dust and dirt in the optical path somewhere. Things directly on the sensor can appear nearly focussed, things on the lens of a refractor can appear grossly out of focus. These things look to be between the two. Are you using any filters near the sensor?

    in reply to: CCD Astronomy magazine #628493
    Dawson
    Participant

    Thanks to Denis I now have a complete set of these. The numbering is odd (and incorrect) and is as follows:

    Spring 1994, Vol 1, number 1 (“Premier issue”)
    Summer 1994, 1, 2
    Fall 1994, 1, 3
    Winter 1995, 2, 1
    Spring 1995, 2, 1 (it should be 2, 2 but presumably misprinted)
    Summer 1995, 2, 3
    Fall 1995, 2, 4
    Winter 1996, 3, 1
    Spring 1996, 3, 2
    Summer 1996, 3, 3
    Fall 1996, 3, 4
    Winter 1997, 4, 1 (final edition)

    Thanks also to Jeremy Shears for giving me the original copies a few years ago.

    James

    in reply to: Planetary “parade” #628415
    Dawson
    Participant

    Yes, the Mayor emailed me to see if she could come to the observatory tonight for the spectacle.

    in reply to: CCD Astronomy magazine #628405
    Dawson
    Participant

    Denis, thank you. I’ll email you my address.

    If anyone else has copies, I’ll still need:

    Winter 1994
    Spring 1997
    Summer 1997
    Fall 1997

    James

Viewing 20 posts - 21 through 40 (of 227 total)