Grant Privett

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Viewing 20 posts - 341 through 360 (of 480 total)
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  • in reply to: Observatory Planning Permission #580689
    Grant Privett
    Participant

    What were the grounds for rejection? Was it because the building is listed, because its in a conservation area or something more mundane like being over 2.4m high and near a boundary?

    in reply to: Possible nova in M31 #580613
    Grant Privett
    Participant

    You got more than me!

    Yeah, the coding is fun. More fiddly, than difficult. I wrote some in VB6 a few years ago – that used Source Extractor output, but it could just as easily have used Pisa or Daophot instead.  I imagine many would use Python instead of VB6 these days. 🙂

    in reply to: Sky and Telescope #580589
    Grant Privett
    Participant

    The problem is it went from owners who wanted to make a living to owners who wanted to be rich with the minimum possible effort.

    You see it in business a lot. Buy something good, reduce standards, cut costs and milk that asset!

    in reply to: Lunar Eclipse Tonight #580580
    Grant Privett
    Participant

    In Salisbury it was hopeful when I went to bed, but at 02:50 and 04:15 it was thick cloud…. The sort of cloud that says, there may be a moon in there somewhere but you’ve no idea where.

    Ho hum. Perhaps I should have moved east when I retired.

    in reply to: Sky and Telescope #580572
    Grant Privett
    Participant

    The magazine changed after it was taken over. It went from being focused on the real enthusiasts with good (substantial) equipment review, observing accounts from experienced observers and cutting edge stuff, to a slim shadow of its former self and devoid of interest to all but beginners.

    It still has some good writers, but a lot of the content is fairly lightweight.

    Shame.

    in reply to: Which planet is closest to Earth ? #580544
    Grant Privett
    Participant

    Closest now or closest ever?

    in reply to: Sirius B #580529
    Grant Privett
    Participant

    Touche. 🙂

    in reply to: Sirius B #580527
    Grant Privett
    Participant

    Yep. Its no big deal. We disagree. It  happens.

    But, should I respect that saying from Feynman more because he was an authority on quantum electrodynamics?

    Ho hum. Back to the gardening.

    in reply to: Sirius B #580525
    Grant Privett
    Participant

    I think that, if you look back at my posting, you will find that I don’t say that it is the worst. If Owen wants to defend that position, thats entirely up to him. 

    If asked an opinion, I would say it is much the same as all the others, only with a more UK slant in equipment choices. But thats hardly pouring praise on it! Some discussions will be sound and informed, some average, others will be hijacked by fools.

    The net gave us access to more knowledge and with that came a greatly increased supply of gibberish. I think you will find that what I said can be summed up as “The advice may only be worth what you paid for it”. 

    I wish good luck to those of you who do help add quality to the fora and admire your tenacity, but find that what I have to do already fills my waking hours. 

    Also, I don’t think its sniping to point out that a source of information may be significantly suspect.  

    in reply to: Sirius B #580523
    Grant Privett
    Participant

    I don’t know about Owen, but I certainly find you have to take whats there with a large pinch of salt.

    I just looked at a discussion in the deep sky section about whether M31 was a naked eye object and another in the imaging section on what affordable CCD camera to buy. Didnt exactly inspire confidence. 

    Looking more generally, there were postings from participants that were at best naive/lazy (even some with 20,000 posts), others who slavishly followed someones opinions because they had taken some nice pics and a few were clearly just plain biased in favour of stuff they had owned. I have no doubt it also has a percentage of observers who manage to “see” rather more than their instrument actually delivered and enjoy the immediacy of the applause available.

    Personally, I couldnt say its worse than CloudyNights or any other fora but, while appreciating a proportion of participants will undoubtedly know their stuff, theres very much a need to be able to filter out the noise – and that can be difficult while you are yourself inexperienced. 

    in reply to: Sirius B #580496
    Grant Privett
    Participant

    You can understand Owen’s concern though, as (above) an experienced observer manages it twice in 30 years while using a 300mm Mewlon and some other very useful sounding instruments and yet its now being seen in scopes much smaller than that used to discover it. Yes, optics are better now and baffling has improved, but the MKI eyeball hasnt changed much (and mine could certainly do with an upgrade). 

    And I’m with him on newsgroups, sometimes the content is low quality.

    Raises an important question about observing dim companions of bright stars.

    in reply to: Sirius B #580487
    Grant Privett
    Participant

    Probably more convincing if it had also been unknown in the west at the same time.

    Would love to see the artefact that proves them right.

    in reply to: 2019 Quadrantids – Radio Detections #580475
    Grant Privett
    Participant

    Nice looking data. For those of us who are ignorant of all things RF, what is Moonbounce?

    Also what sort of equipment did you need to accomplish such a good result?

    in reply to: New Horizons about to fly past ‘Ultima Thule’ #580449
    Grant Privett
    Participant

    The “Still Alive” signal should hit ground 15:39UT today together with a bunch of status telemetry. First results tomorrow hopefully.

    Should be fun. An exciting time to be alive.

    Grant Privett
    Participant

    Did they also record changes in Mira? You would think that if they are paying attention that closely then they should have.

    in reply to: Apollo 8 observations – Sky and Telescope #580426
    Grant Privett
    Participant

    It says Henry Hatfield contributed observations. Would this be to the defunct BAA Section associated with artificial satellites, do you think?

    in reply to: Windows Free Zone #580423
    Grant Privett
    Participant

    Not arguing against DAOPHOT at all as I use it as part of a processing pipeline I have too. 

    Wouldnt say DAOPHOT is any more unfriendly than any other, merely that IRAF can be poorly documented and debugged. I find Starlink more robust, but as I wrote some of it, I would say that.

    in reply to: Windows Free Zone #580419
    Grant Privett
    Participant

    There is a version of DAOPHOT available for Python too – I always found IRAF as user friendly as a punch in the mouth and poorly debugged. The Python DAOPHOT seems to work okay for me. The major difference over the Fortran version is that it doesnt handle a bad pixel mask. Execution times similar (having no bad pixels to worrry about makes life lots easier).

    I must admit I was under the impression DAOPHOT assumes a Gaussian profile so it can get unhappy with distorted images – theres a parameter for limiting how eccentric it will tolerate.

    I did a quick study a year or two back and looked at Source Extractor, PISA and DAOPHOT. Each had its quirks. DAOPHOT was primarely aimed at stars while Source Extractor and PISA could do both stars and galaxy photometry. Source Extractor was very good but the documentation a little incomplete and PISA was by far the most memory efficient. When the source was star shaped they all did similarly in terms of the detections, but Source Extractor could use the WCS (I don’t think PISA did, but I might be wrong). Bottom line was they all had efficient detection approaches and if you already  had code to handle the pixel space coordinate to Ra/Dec conversion, each was well worth having.

    in reply to: Christmas meeting Livestream #580339
    Grant Privett
    Participant

    Thanks for the headsup.

    in reply to: Windows Free Zone #580268
    Grant Privett
    Participant

    Source Extractor is available under Linux – and also in a limited form (no WCS support) under Windows. Would that or IRAF/Starlink be of any use for initial data extraction?

Viewing 20 posts - 341 through 360 (of 480 total)