Grant Privett

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Viewing 20 posts - 121 through 140 (of 470 total)
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  • in reply to: Journal delays #614900
    Grant Privett
    Participant

    My Journal reached Salisbury today!

    in reply to: Spectral line modelling #614883
    Grant Privett
    Participant

    Have you submitted it to the Journal yet?

    in reply to: Unistellar and FITS #614829
    Grant Privett
    Participant

    Oh, I think I missed something there….

    You have to ask them to give you a copy of your data as FITS? Theres no SD card or something where all your session data is saved that is accessible to you? Does this mean you don’t have anything else other than a jpg/png they serve up to you live? I’m surprised at what you said but, clearly, they have found a market.

    Just to be clear, as I have never used one, what is the bit depth on the png provided? I think that both 8 and 16 bit are legal png formats, though some software doesn’t like 16 bit pngs or TIFFs.

    If the png is 8 bit (or even 3x 8bit) then they have rather constrained you to the Citizen Science route, as that makes it harder to do any on your own. But, I don’t know the png file format well enough to judge if its metadata content could be used to populate a FITS header.

    in reply to: Composite images #614808
    Grant Privett
    Participant

    The hint is in the name. The vast majority of deep sky images are exactly that, pretty pictures. Theres no scientific rationale for taking them and no need for the person doing so to worry about gamma stretching or sharpening – its about showing the structures and elegance in an object in a tasteful and appealing way. Look at how many people return to an object (such as M42 or M16) every few years because improved skills, location or instrument mean they will be able to pick out more detail or create an image more eye catching. The target itself has not changed. It is a quest to get the maximum performance from the kit you can afford: we all know that if we had a PlaneWave 24″ in Chile, an Andor camera and unlimited time on it we could take better pictures, but most of us cannot afford one, so we strive to do the best we can.

    With planets its also about detecting features (dust storm, cloud feature, polar cap) but, they change which makes life much more interesting.

    Its the change aspect that makes variable stars, the Sun, aurora, meteors and comets interesting too. Its why I spend most my nights chasing variable nebulae.

    I have seen people post pics in the BAA Gallery that were clearly composites and they have not mentioned it. That I must admit to disliking.

    in reply to: Unistellar and FITS #614807
    Grant Privett
    Participant

    Yeah, I read some of the AAVSO pages on this. Sounds like they are not in a hurry to provide FITS files – which is kind of weird given how its a trivial bit of coding. A doddle in C and trivial in Python.

    Sounded like the way the Citizen Science is done is taking observations and sending them to someone else who does the data reduction… Sounds a bit dull to me. Data reduction is what cloudy nights are for.

    Some mention of the code being open sources and then of release of an API, but nothing yet – and promises are cheap of course.

    in reply to: Gyulbudaghian’s Nebula #614750
    Grant Privett
    Participant

    Thanks for the headsup. Your observation really does suggest we all need to keep a close eye on it in the months ahead.

    in reply to: Gyulbudaghian’s Nebula #614695
    Grant Privett
    Participant

    Hi David,

    I think that V shape and the right hand wing (on your image) feature have been faintly visible on some unfiltered images since the summer.
    Such as here:
    https://britastro.org/observations/observation.php?id=20221129_230438_ac6a218c4ac94ed0
    and
    https://britastro.org/observations/observation.php?id=20221129_230930_656c96e63f3df518

    Was it absent in your similarly exposed Rc filtered images from earlier in the year? The nebula is heavily reddened, so you might well see changes before those of us working unfiltered noticed them.

    Do you still measure the nebulosity brightness at all? What does that curve say?

    Would be nice for this or McNeil’s to reappear at last. Looked at Thomme’s last night and can’t see much change since I started looking at it and McNeil’s is absent with V1647 Orionis in the 19.5-20.5 mag range when skies are clear enough to detect it.

    Happy Solstice!

    Grant

    in reply to: Artemis #613612
    Grant Privett
    Participant

    From Wiltshire, at 0630 the Sun is about 8.3 degrees below the horizon. TheSkyX still shows 1st and 2nd mag stars visible at that time, but I don’t know how accurate that is.

    I think this guarantees cloudy nights for a week…

    in reply to: Partial solar eclipse of 2022 October 25 #613280
    Grant Privett
    Participant

    You probably need to add dancers, a 120bpm backing track, some dry ice, lasers, a conspiracy theory and someone being humiliated to keep social media fans tuned in.

    in reply to: Lucy in the sky…. #613173
    Grant Privett
    Participant

    Cloudy in Wiltshire on Sunday and away on business now… Great.

    Good to see someone got it though.

    in reply to: Partial solar eclipse of 2022 October 25 #613063
    Grant Privett
    Participant

    Seems to be working. Looks like thin cloud presently.

    There are a couple of small dust patches – as you said – but nothing thats going to detract from a good chunk of the Sun being obscured…

    in reply to: DART spacecraft impact with Dimorphos #612729
    Grant Privett
    Participant

    It was fun to watch and some of those observing from the ground did quite well too…

    https://twitter.com/fallingstarIfA/status/1574583529731670021?s=20&t=bSNlZJgGJmZCFPEEcFqEvA

    3 tonnes of TNT appears to have made a pretty impressive cloud of debris.

    in reply to: Expensive book #612396
    Grant Privett
    Participant

    Yep. Dangerous talk as it disagreed with Aristotle AND Scripture!

    Galileo got house arrest for more than a decade and banned from publishing…

    in reply to: Artemis #612188
    Grant Privett
    Participant

    That sounds very hopeful. Would love to see the burn…

    Of course that means overcast skies plus fog for the next couple of weeks then. 🙂

    in reply to: Artemis #612156
    Grant Privett
    Participant

    At -27 theres not much hope from home for me then as my dome blocks everything below -10 and a nearby hill blocks everything below -15.

    Damn.

    in reply to: Antitwilight Sky #612038
    Grant Privett
    Participant

    Cloud tends to be below you when you are at 2400m high. 🙂

    in reply to: Antitwilight Sky #612011
    Grant Privett
    Participant

    After seeing the pictures from Giovanni, I dug out an old picture….

    https://britastro.org/observations/observation.php?id=20220818_202738_4a8c0021466584a7

    in reply to: Artemis #612007
    Grant Privett
    Participant

    Ah, excellent. I looked and they appear to have a place holder object name in place, so it looks hopeful.

    It could be a lot of fun. It looks like it will be taking a while to get there.

    in reply to: Antitwilight Sky #611998
    Grant Privett
    Participant

    Lovely images. The Belt of Venus is rather beautiful.

    I only see it occasionally in the UK. Does it require particularly transparent skies to appear?

    in reply to: Phew, that’s a relief! #611656
    Grant Privett
    Participant

    I’m sure the Chinese space station will provide other opportunities for hiding under the table.

Viewing 20 posts - 121 through 140 (of 470 total)