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Gfamily

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Posts posted by Gfamily

  1. 7 hours ago, dd999 said:

    No, I always use the two star alignment. Will this also require a north level alignment and a level scope to start?

    Last time I took it out, I knew I only had a few minutes to set up as clouds were building up, so I did a 2 star align, even though only Altair was properly visible from my location.

    I selected Arcturus as the second star (even though it wasn't visible). Centred on Altair, let it head off in the general direction of Arcturus, up-and-right a tiny bit to let me hit the OK button, and then set it to find Saturn.

    It wasn't in the 32mm eyepiece, but it was very close - easily in the finder.

    I know there are some iffy ones around, but it can be a very easy mount to align.

    This was using the app in alt-az mode.

    So, in response to your question, no; two star align starts with the first star. 

    Level and North is an option when you're not sure which stars you're looking at (or for a daytime/early evening alignment when finding stars isn't easy).

  2. A couple of thoughts...

    As you used the same 15mm eyepiece in testing both, you'll have been observing at 66x through the refractor and at 93x through the Mak.

    That might be why the Mak was looking softer. Do you have a 20mm eyepiece so you can compare the two scopes' images at the same magnification?

    Secondly, you said you were looking at chimneys as your test; I find that the daytime image is generally lower contrast than you'd expect if I'm using my SW 127mm Mak, but it's ok at night.

    I don't have a refractor to compare, but I sometimes wonder if a Mak is more affected by background light.

  3. 4 hours ago, Waldemar said:

    Keep in mind that the Canon 40D is a big, heavy camera... Beter choice would be the 750D for example.

    Better than both might be a mirrorless camera.  

    I recently picked up a second hand Sony A5000 body, and that has the advantage of being almost half the weight of my Canon 1000 ds body and 1/3rd the weight of my Pentax K5. 

    However, I wouldn't recommend the A5000 for a few reasons - I would say check out any camera you are considering for these.... 

    • it doesn't have a Live View option, so you can't check the focus etc on a big screen before taking the image
    • It forces a Noise Reduction 'dark frame' in many cases (possibly all) which isn't optimal as it doubles the time to take each image. 
    • If you choose RAW image format, you lose some of the functionality (such as on-screen focus check) 

    Particularly for a lightweight mount like the Star Adventurer, managing the weight on the mount is important if you want to get decent long exposures, and if you can reduce the weight hanging off the back of the scope it can make a real difference. 

    Hope this helps - and if anyone knows of a mirrorless camera that is recommended, please chip in... 

  4. Hi - I've not seen the Star Discovery before; it looks quite interesting. 

    I recently bought the AZ GTi and have used it a couple of times so far. It is very straightforward to use - and the "level and north" two star alignment is very intuitive. 

    I would assume that the software and operation will be more or less identical for both, and so their performance would be equally good.  It's really good to see that the Star Discovery has the Freedom Find encoders - as that means you can manually move it to 'close to' your next target and it'll keep its alignment. 

    In principle, the SD may have a slight advantage as it puts the weight of the scope over the centre of the tripod - but on the other hand, the AZ GTi allows a telescope to be pointed directly to the zenith as the clamp is offset from the centre-axis. 

    I think the AZ GTi may have a couple of advantages over the SD though:,

    • Firstly, it has a separate Handset Socket for the Synscan handset.  As I have a spare handset, it means I don't have to use the App for all movements, while I can still use the app for the initial set up and for selecting targets. 
    • Secondly, the AZ GTi can be mounted on a wedge, and there is a 'Pro' version of the app that means you can use it in equatorial mode (though you may need a counterweight to balance a heavier telescope) 

    One thing to look out for is that there are mount and telescope bundles that include the AZ GTe mount - this is a cheaper version of the GTi which doesn't include the Freedom-Find encoders, and I think you would miss that if you didn't have it. 

    Hope this helps 

  5. I am pretty sure that your last two adjustments to centre the star have to be "Up" and "Right" - and that will allow you to tap the icon. 

    The reason it is done like this is to ensure that there is consistency regardless of the scale of backlash in the gears.  

    Try again bearing this in mind. 

    (I have the same app that I use with my AZ GTi and it works like this)

     

     

    • Like 2
  6. A for Astronomy – A hobby with which people can enjoy the night sky, the moon, planets and stars. A hobby that can be done for free, but rarely is.

    B for Betelgeuse – A star that threatened to do something really interesting for a while, but didn’t

    C for Comet C/2019 Y4 – A comet that threatened to be really impressive for a while, but probably won’t

    D for Dark Skies – A condition that we would love to enjoy, as we’re having a few clear nights, with fewer planes in the sky, but we’re all stuck at home, so we can’t go and find these dark skies.

    E for Evenings – stretching longer and longer as we move towards the Summer.

    F for Fornax – a constellation that’s near, umm somewhere. I think I knew something interesting about it – didn’t one of the Hubble Deep Field images come from Fornax? Anyway, not visible from here.

    G for Galileo – one of the first people recorded as having used a telescope to look at the night sky.  As it ended up in his House Arrest, clearly it didn’t work out well for him either, but we have something in common.

    H for Herschel – the first professional female astronomer, famed for discovering many comets. Also her brother and nephew, who worked on a catalogue of objects; obsessives can make it their mission to see all of them.

    I for InfraRed – a part of the electromagnetic spectrum (discovered by William H) for which you need to travel to high altitude or into space to use for astronomy – well, maybe next year!

    J for Jupiter – the king of the planets; it’s currently visible in the early morning light, so a great alternative to your insomnia.

    K for Kepler – Borrowed someone else’s theory and used someone else’s data. One of the first modern scientists.

    L for Light – the most precious gift sent from astronomical objects to us observers across billions of miles. It gets lonely though, because it doesn’t hesitate to join up with lots and lots of our human made light when traversing the last 60 km or so.

    M for Magnification – the thing that most non-astronomers think is important, Oooh! x625

    N for Night-time – when we practice our dark arts; they say practice makes perfect – well, we’re still practicing.

    O for Occultation – a phenomenon when one object obscures the light from another, for example, when a planet or asteroid blocks the light from a star.  Most often occurs with clouds.

    P for Pluto – used to be a God, then a Planet, then a cartoon dog, and then (controversially) not a Planet any more. We used to have proper controversies in Astronomy: the nature of the spiral nebulas, the Big Bang vs Steady State, proper controversies. So maybe P is for Proper controversy instead.

    Q for Questar – a brand of telescope for people who don’t know the meaning of “Oh, isn’t that quite expensive for a hobby?” No, that does NOT mean people like us; we can justify every penny we’ve spent on Astronomy.

    R for Refractor – the best type of telescope (runs off to get popcorn)

    S for Stars – strangely, it’s almost the case that the least interesting thing in amateur astronomy is a single star – we love them in the plural and will spend a fortune on GOTO systems so we can see them in binaries, asterisms, open clusters, globular clusters and galaxies, but a single star by itself – just a dot.

    T for telescope – a device for taking light that has travelled free across millions of kilometres and compressing it into an image that we can then inspect with a magnifying lens. Like an insect on a pin.

    U for Uranus – prime evidence for us astronomers' sense of humour

    V for Venus – generally the answer to the question “what’s that really bright star I can see in the evening, is it the Pole Star?”

    W for Cassiopeia – don’t argue.

    X for X-Ray – it always comes down to either X-Ray or xylophone, and although Sir Patrick played a xylophone we don’t use them in Astronomy.

    Y for Year – the time period based on the Earth’s orbit around the Sun. Quite straight forward,  which is why we have Sidereal Year, Tropical Year, Anomalistic Year, Heliacal Year, Julian Year, Gregorian Year, Sothic Year, and several others.

    Z for Zodiac – the astrologers’ 12 star signs through which the sun passes through the year. We’ve moved on now, so we now have 13 constellations through which the sun passes in a year. So clearly we’re better, like that bit from Spinal Tap.

    • Like 5
  7. Announcement from the NWAF committee

    It is very sad for us to say this but in view of the escalating Covid-19 situation, the North West Astronomy Festival management committee have reluctantly concluded that it is in everyone's best interest that we re-schedule the Festival to 2021.

    We have made huge progress in planning the event and as a team we are well positioned to work towards an even better Festival in 2021.

    We would like to thank everyone for their support so far, especially the astronomy societies who have been so keen, and the wonderful speakers and traders who had agreed to come along.

    We will be back in touch as soon as things settle down. In the meantime, watch for updates on our website www.nwastrofest.co.uk and via social media.”

  8. NWAF-Logo-with-TNWAF-banner-text-greyscale-light-ink@2x.png

    Update on 18 March 2020 

    In the light of the unknown duration of special measures during the Covid-19 epidemic, the decision has reluctantly been made to postpone the NWAF to 2021

     

    The North West Astronomy Festival is back, with a new date and a new venue. 

    https://nwastrofest.co.uk/

    The North West of England's only major Astronomy Festival has moved to The Engine Rooms at Birchwood, Warrington, WA3 6YN (convenient for M6 / M62)

    and has a new date Saturday 24th – Sunday 25th October 2020

     

    • Like 3
    • Thanks 2
  9. 2 hours ago, laudropb said:

    So sad to hear this. I got to know Andrew well during 3 trips to Astrofarm. His love and knowledge of astronomy always shone through. He even got me to take some DSO images and patiently went through the best way to process them with me. Something I never intended to do. Two of these images now hang on my study wall. Every time I look at them I will remember the kind, cheerful man who became my friend.

    RIP Andrew and condolences to Sue and his family

    Andrew had moved back to UK last year, but Sue is still running Astrofarm, with the "Astro-facilities" available to guests as before. 

  10. I'm saddened to announce the unexpected death of Andrew Davies, astronomer, teacher and inspiration to many.
    He helped many develop in our great hobby, through his teaching, the clubs he helped set up, through his work fronting the North West Astronomy Festival in Runcorn, and in setting up Astrofarm France. 
    He will be much missed. 

    Screenshot_20191222-212159.jpg

    • Like 1
    • Sad 8
  11. On 17/12/2019 at 13:05, DaveL59 said:

    well assuming the usual H+O2 fuelling, perhaps not as much as you'd think. but that said the footprint for building it all etc, a fair bit...

    As Cyril has pointed out, SpaceX use RP1 (basically refined paraffin) and LOX as fuel and oxidiser - the refrigeration required for Liquid H2 is much greater than you need for Liquid O2, so the engineering challenges is far greater, and apart from that, the mass density of LH is much lower than that for RP1 - which would require significantly larger fuel tank stages. 

    Although the Saturn V rocket did use LH / LOX, it was only in the Second and Third stages. If they had tried to use it for the First Stage, the tanks would have had to be about twice the diameter.

  12. You can play with the scale factors on this Google Sheets on my drive

    https://docs.google.com/spreadsheets/d/1GoGmffEo6rH0E4C0O5qQ-nLCOocw3P8YzHN6r1oW3RQ/edit?usp=sharing

    You should be able to select your 'base' planet using the blue dropdown, and then select what size you want it to be using the left hand yellow cell. #

    The right hand yellow cell allows you to select the size you want for the orbits (obviously a completely different scale to the planets). 

    I have a 15 metre tape that works well for Sun - Neptune, so Jupiter at 2.6m fits that scale. 

  13. Our Astro Society was asked if we could lead a couple of sessions for a local Cub scouts group to prepare them for their Astronomy Badge. 

    A lot of the content is around the Solar System, so we thought that we'd assemble some appropriately scaled models.  At a craft shop we were able to pick up Polystyrene balls in following sizes which are pretty close to representative. 

    10cm - for Jupiter

     8cm  - for Saturn (about 5mm too small)  to which we added a card 'hoop' for the rings - inside diameter  9cm, outside diameter 19cm

     4cm  - for Uranus and Neptune (c 5mm too large)

     1cm  - for Earth and Venus  (1 & 1.5mm too large respectively)

    0.5cm for Mars and Mercury (Mercury about 1mm too large) 

    If you can get a beachball about 1 metre in diameter, that will stand for the Sun. 

    We painted the 'planets' in appropriate colours using acrylic paints and they looked pretty good. 

    Edited to correct size for Mars / Mercury from mm to cm.

    • Like 2
  14. On 18/10/2019 at 18:08, Dave_D said:

    admittedly, i later got another email from a different person basically saying that :D still a funny first reply though

    as to the being overly welcomed... well most people steer me a wide birth especially when i got my trenchcoat and boots on 🤣🤣🤣

    If that's all you have on I'm not surprised! :)

    • Haha 3
  15. Hi and welcome. 

    You're fortunate to have a few local astro societies if you want to meet up with like minded people. I don't know anyone from Chester AS, but they're quite local to you. 

    If you're able to get over to near Old Colwyn, the North Wales AS meet for observing at the Community Centre at Llanelian on the second Tuesday of the month - i.e. tomorrow. If it's not clear, they'll have a short talk or two instead.

    They also have a talk meeting at Llanrhos Old School (nearer Deganwy) on the fourth Wednesday of the month. 

    They're a really friendly group, and I try and go to most of their 4th Wednesday meetings. 

    • Like 2
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