Gfamily

I have a similar scope (Meade 8"SCT) and I find I am often looking for a wider field of view, so you might also want to consider going for a 32mm eyepiece as well. However, the 9mm Ex-cel is also a very nice eyepiece, and for planets & the moon, it'll give you great views. For open clusters though, the narrow field of view of a SCT can make them fail to stand out as they should. There's a general rule of thumb, that under everyday skies, the limit of magnification is with an eyepiece not much shorter (in mm) than your f/ratio. Higher magnifications are too much affected by atmospherics. It's only a rule of thumb, but worth bearing in mind.

I bought a SW 102 Mak (on a SynScan mount) when I was getting my second scope, but always found it a disappointing performer when looking for DSOs at home. If we took it away to dark sites it was ok, but it struggled with any much level of light pollution. I relatively recently picked up a second hand 127 Mak and it's now my 'go to' scope for use at home or away, so it's the one we take way with us on holidays. I only really use my 8" SCT for star parties now.

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).

Yes, without seeing for ourselves we're in no position to judge, and it's quite likely that it's not one you'd want to take on. Like so many things, it would be easier if local clubs were meeting and you could take it along to get a second opinion. Best of luck though.

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.

Have you tried running it via a computer control? Stellarium allows control of NexStar mounts (I've done it with my Meade). You'll need a suitable cable of course.

I can't offer any advice on the camera - but I notice that Rother Valley Optics have a second hand one on sale for £350, so if you can get one for £200 that sounds like a deal. Here's the advert if it's of any use https://www.rothervalleyoptics.co.uk/second-hand-starlight-xpress-sxv-m8c-one-shot-colour-ccd-camera.html

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...

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

Does anyone know if the instructions actually say this? Who actually reads instructions these days I only know about it because I read somewhere that Celestron have the same 'rule' on their SE mounts, and guessed it might be the same when the app wouldn't accept my 'Complete' on the first star.

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)

This thread may be useful. Olly Penrice is very experienced - and in the thread he says that you need to look for an image size of 45-46mm to be able to use full frame.

A new NASA documentary has been produced about the mission https://www.youtube.com/watch?v=WM8kjDF0IJU

The excellent 13 Minutes to the Moon podcast (original series about the descent of the Apollo 11 Lunar Module) is having a second series about the way the Apollo 13 mission was saved. https://www.bbc.co.uk/programmes/w13xttx2

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.

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.”

Better than clashing with one or the other though!

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

A memorial service for Andrew will be held at the Wincham Hall Hotel, Wincham near Northwich, Cheshire at midday on Tuesday 28th January.

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

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.

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.

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.

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.

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