Equipping a school observatory from scratch

[glowingturnip]

Hi All,  I would appreciate plenty of help with this project if I may...

The school my sons go to is building a new science block, due to be completed for the upcoming autumn term.  They have a budget to put an observatory on the roof, and I'm very fortunate in that they have approached me to assist in suggesting suitable kit and helping them get it all set up (and help with clubs occasionally, and dare i say it, use it for out-of-hours imaging for myself once in a while !)

So far they have commissioned a 2.7m diameter dome (manual) and a pier.

Most of the usage will be observing, and then mostly solar system, though I am suggesting they equip for webcam imaging of planets and DSLR imaging of the moon and sun.  DSO imaging is a little out of scope (CCD camera is definitely out of scope but the school has plenty of DSLRs) but I am suggesting it should be DSO ready, so a guidescope and guidecamera as well.

Particular emphasis on solar viewing and imaging, since for non 'club' use most boys will use the observatory in the day during school hours.  To this end, I am thinking both a white light solar filter (built into an appropriate cap in the DT lab) for the main scope and also Ha solar viewing.  I'm thinking a coronado scope mounted piggyback with the main scope if that is possible, or failing that a solar Ha filter for the main scope.

I'll be posting some follow-up threads as I work my way through my 'shopping list', but to my first questions then...

The scope will be pier mounted, and budget allows for around £4.5k for scope and mount.

The mount should be equatorial, motor driven with synscan or goto, and be able to communicate with planetarium software and guiding software (all easy enough).  Ideally, I would like to be able to mount both the main scope, a coronado scope and a guidescope all piggybacked on the same mount, which i guess is going to be a fair amount of weight to carry, especially once the camera and everything else is on there too.  Is such a mounting commonly done (pics please !), or am I asking too much ?  Any particular mounts you would recommend, and what kind of rating should I be looking for ?

For the main scope, obviously aperture is key, we're probably looking at 12".  A reflector is probably not a good choice, since some of the shorter boys won't be able to reach the eyepiece if it's on top of the scope for some targets.  Since i am thinking that the scope could be used for prime focus DSLR imaging of full disc lunar and solar, then the focal length shouldn't be too long (750mm to 1000mm ?).  

We've had one quote already that suggested a Meade LX200ACF 12" (http://www.f1telescopes.co.uk/shop/meade-lx200-acf/meade-lx-200-acf-12-inch-uhtc-goto-telescope-without-electric-focuser/) but a) that comes with an alt-az mount which I don't think we want and it seems to be a very long focal length of 3000mm.  An alternative I've seen so far is the Celestron CGEM DX 1100 SCT (http://www.f1telescopes.co.uk/shop/celestron-cgem-dx/celestron-cgem-dx-series-1100-sct-telescope/) which has an eq mount, but is still a 2800 focal length.  Also both are cassegrain types, so do I need to think about coma correction, mirror shift and collimation ?

So any suggestions for large aperture scopes with a focal length suitable for a full disk moon at prime focus DSLR, and a highly-rated equatorial mount ?

Cheers

Stuart

[ronin]

Just tell the LX that it is on an equitorial and it will be fine.

Bolt a pillar to the floor if possible and forget a tripod for the EQ.

Where in London are you ??

[GuillermoBarrancos]

Sadly, if you want to use EQMod together with Stellarium, you are limited to Skywatcher SynScan mounts. If the school is building a pier, then you could have a look at the EQ8, which you can pick up for £2500 mount only.

[101nut]

In a school a coupled big scope and solar scope is potentially dangerous - think very seriously about risk assessments! I only use an Ha scope at school but *I* set it up and *I* put 'danger' notices out and *I* check it out before anyone other than me uses the kit. I hate to imagine something as simple as a light-fingered kid taking an end cap off the main scope whilst the solar scope is in use ...

AndyG

[glowingturnip]

Andy - yes, very well noted.  I was already thinking of getting large scarily worded danger signs put up in the observatory and of having a strict adult supervision and handling policy put in.  I did suggest a separate tripod-mounted Ha scope to be taken outside on nice days, but room on the roof doesn't really allow for that (and we don't want them falling off the roof either !) .  I wonder if it's possible  to get lenscap locks to stop them coming off by accident ?  As you say though, I'll make sure the school do the correct risk assessments first, I don't want any blinded kids on my conscience.

Guillermo - is that the same situation for all planetarium software needing an SW Synscan mount ?  I personally use Redshift and a synscan add-on on my Celestron scope, would Redshift need an SW Synscan mount too ?  Mind you, just googled the EQ8 - looks nice !  That's another question I have to ask too...  what's the best Planetarium software ?

[GuillermoBarrancos]

Only if you want to Control the Mount via EQMod+ASCOM platform. http://eq-mod.sourceforge.net/reqindex.html

It basically gives you full GoTo control over the mount via the computer, without the need of the handset.

I had the CG5-GT with 8" SCT for several years, but never tried controlling it via the computer. So I don't know if the Celestron Mounts are controllable via the ASCOM platform and if there is any EQMod alternative software for Celestron Mounts.

I am sure there are others with CGEM and CGE Pro mounts who can answer that.

[Cornelius Varley]

Only if you want to Control the Mount via EQMod+ASCOM platform. http://eq-mod.sourceforge.net/reqindex.html

It basically gives you full GoTo control over the mount via the computer, without the need of the handset.

I had the CG5-GT with 8" SCT for several years, but never tried controlling it via the computer. So I don't know if the Celestron Mounts are controllable via the ASCOM platform and if there is any EQMod alternative software for Celestron Mounts.

I am sure there are others with CGEM and CGE Pro mounts who can answer that.

You don't actually need EQMOD or equivalent to control a goto mount via a computer planetarium software.

[GuillermoBarrancos]

You don't actually need EQMOD or equivalent to control a goto mount via a computer planetarium software.

Yes, ofcourse you are right. When you already got the GoTo handset, you connect via the handset.

EQMod replaces the SynScan handset and talks directly to the mount.

Just found this:

http://eq-mod.sourceforge.net/docs/PC_Control_Options.pdf

So with the Celestron handset it's basically getting the correct cable and install Planetarium and the ASCOM platform / Nexstar drivers.

[glowingturnip]

makes sense, that's how mine's working, plugs into the port on the handset.  Hmm, something else to think about

[glowingturnip]

so I'm starting to narrow the choices for the main scope down to...

Meade LX200 12" (£2550, focal length 3048mm, aperture 305mm, f10) - think this might be too long a focal length really though, even with an f6.3 focal reducer the full moon disc won't fit on a DSLR chip by my reckoning, think I need max 2800mm

Meade LX200 10" (£1700, 2500mm, 254mm, f10)

Celestron Edge HD 9.25" (£2700, 2350mm, 235mm, f10) - expensive for a small aperture ?

Celestron 11 A XLT (£1600, 2800mm, 280mm, f10) - seems cheap for the specs, is it any good ?

So of those, I'm starting to think the Meade 10" is going to be the best choice, assuming I can get a focal reducer for it.  Any comments on these scopes, and any others I should look at ?

Thinking of mounting it on an EQ8 mount on a pier.

[Stu_2011]

I would factor in reliability into the equation as well as it's school funds. Meade make fantastic SCT optics but the mount electronics seem to have questionable reliability. It may have got better now but when I looked a few years ago this swung me towards Celestron. The Celestron electronics do seem better.

Sent from my iPad using Tapatalk

[Stu_2011]

Oops, just read the end of the post. It's going on an EQ8 mount so comments on Meade electronics not relevant. Sorry

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[glowingturnip]

yeah, I think so, but that helps, thank you - wasn't very keen on the alt-az mount that seems to come with the Meades, even if it is put on a wedge, but if the electronics aren't top quality too, I think that makes that choice easier

[ollypenrice]

I'm a former teacher and now a holiday astronomy provider. This doesn't make me an expert but it means I have a point of view. Also I disagree with almost all the assumptions so far on the table! I'm ever so sorry about that but I'll carry on regardless, assuming you'll ignore me if you wish.

Aperture is a poisoned chalice with beginners. It simply doesn't interest them unless you have a very dark site. Now I do have a very dark site so I can get a reaction from beginners with M51, for instance. 'Wow, what are all those swirls?' is a verbatim quote from a first timer with our half metre Newt. But from a poor site it doesn't matter how much aperture you have, you will be trying to sell feeble grey smudges and you will turn people off. This is not what education is about, it is about turning people on. Beginners don't care about faint fuzzies. You give them the Crab in a 14 inch and I'll give them the Pleiades in a 4 inch and I'll have the longer queue. Trust me.

From a poor site the solar system objects can be great. You would get a fine view of Saturn and Jupiter from a big SCT but equally you'd get a great view from a 5 inch refractor. I have a 10 inch SCT and a 5.5 inch refractor and nine times out of the the refractor wins. Not by much, both are good. For webcam imaging (the best way to capture anything solar system) a big SCT is the clear winner. For visual observing the long focal length is (read this twice) a total catastrophe. So many attractive objects are excluded. A one degree field is not enough to woo beginners. You are condemned to the faint fuzzies and they just don't do it for the public. Now I say this from a seriously dark site (21.9 is our best SQM reading) so from anything less, like urban UK, I'd say it louder still.

If your aim is to capture solar system via webcam and observe solar system visually then go for a big SCT. But it is not going to appeal to a school audience for much else.

Really what we need are lesson plans. Give me those and I think I really could be useful. Will this lesson work, will it not? Who out of 'x' number of students will be doing what, minute by minute? This is what I did for a living and it is what teaching is about. If you don't think in these terms you are not really going to do justice to the kids. You have to come at it from their point of view, not yours. (Can't claim to have been totally strict on this maxim, by the way, but I did my best!!)

Olly

[Russko13]

How old are the kids, have you considered maybe getting a good few dobs of decent aperture, the scopes your going for sound like the kids would be scratching their heads trying to work them out lol with a dob there simple to use and keep things on a low cost allowing for funds to be spent in other areas aswel such as books/guides, equipment, plenty of eyepiece options. Just my 2 pence!!

[Bukko]

Hi, Stuart,

I am really glad that Olly has weighed in to this discussion. £4.5k of a schools'money is a lot to get wrong and I would pay a lot of attention to what he said.

For a work project, we do a lot of "due dilligence" and making sure we fully understand what we are trying to achieve.

I think this is a prime candidate for the same treatment - talk to the school and make a list of targets and review what is required to achieve it. If the aim is purely solar system, then assuming you go with the EQ8, you have around £2k for a scope. This gets a well corrected 4" or 5" refractor, that could be converted for white light solar and perform well for lunar and via a webcam, planetary. At a push, I am sure you could also do pretty well on galaxies. The EQ8 woudl take future upgrades, even doubling up on scopes, so it would be reasonable future proof (I hate that term...)

I have little experience of London conditions, but expect them to be pretty dire, especially compared to Olly's place. Although Ian King Imaging is based in London and he seems to do very well processing DSO's.

Gordon.

[ollypenrice]

Thanks Gordon. Ian also has a remote scope shared with Nik in southern Spain...

Olly

[perkil8r]

Hello, not posted here for a while as I have been rather busy.

I am very fortunate in that I help run our school's observatory which is a monster.

We have a Meade LX200 16". Whilst I appreciate it is considerably larger and more expensive I can say that the LX200's are a very good scope for a school environment. We have ours mounted on a wedge on top of the pier. The one thing I would say though, is that the mount does sound a bit loud and is proun to throwing a tantrum from time to time.

As for solar scopes being mounted on the main tube, I share the concerns however ours is mounted on top of the main OTA, although we often use the Watec with it so no students need to be near the scope in that sense. We do take small groups up though to show them the solarscope working but there isn't a chance for them to start getting close enough to do any harm. Nigh time observing of course is much more hands on.

The LX200 is great for Jupiter, the moon and so on, but it's a bit too long for any Astro Photography with one of the CCD's. I am in the process of buying a Skywatcher ED80 to sling under the main OTA for Astro Photography using the Atik 383.

Be prepared for risk assesments galore though, they wanted us to light each step up to the dome with bright white LED's, in the end they agreed to white paint on the edges of the steps and red bulkhead lamps to illuminate the area.

I'm not sure any of that has helped.

[ollypenrice]

Oh Gawd, the risk assessors! One University had to illuminate its observing site.

Can I ask perkil8r, though, what is the advantage of the huge SCT? Is it really much better on Saturn and Jupiter than something a lot smaller? It just seems an incredibly expensive way to get a view of the planets which might be insignificantly better than that acheived in a smaller scope. And then its enormous focal lengrh kills it for so many other things.

I also suspect (but am not sure) that SCTs are the worst of all for being affected by LP. Someone may have done a back to back, perhaps?

On the wider issue, a large amount of public funding recently went into the building of a 0.8 metre RC costing around six million euros not far from me. Part of its intended use is for outreach, but how well adapted will it be for this? Those of us into astronomy would have a list of targets we'd love to see at high power, but what about the general public? I'd have though that more and smaller telescopes would give a better experience. I'm sure the local politicians will build up a great head of steam around the idea that their region has the biggest public telescope in Europe, or whatever, but is this the point? That's why I think it best to start from the customer's point of view.

Olly

[jambouk]

Trent University in Nottingham have a 16" SCT mounted in their observatory too, and they use it for their undergraduates and postgraduates for doing spectroscopy and stuff as well as showing us members of the public how bright jupiter looks

Jd

[Chris Rowland]

My Astro Society has a CPC1100 on a wedge, in a dome.  It works well for what we do, mostly outreach, casual visual observing and a little light imaging.

One thing to bear in mind is who is going to be operating it.  It will probably be a range of people with different abilities and experience - I'm not talking about the students, the teachers.  If you have something that needs careful operation and set up then you will end up with something that's only used by an elite.

We park and hibernate the scope at the end of each session, then all it needs is be woken up at the start of the next.

There's a lot to be said for fork mount scopes for this sort of thing, where it won't always be used by experienced amateur astronomers.

Chris

I forgot to mention, we have an 80mm refractor piggy backed, that handles the large objects, and make it look much more professional.

[ollypenrice]

Good point about two scopes but two on two mounts means twice as many students active.

Olly

[Davey-T]

Trent University in Nottingham have a 16" SCT mounted in their observatory too, and they use it for their undergraduates and postgraduates for doing spectroscopy and stuff as well as showing us members of the public how bright jupiter looks

Jd

Had a quick look at Jupiter through my 110 refractor the other night, ruined my dark adaption, all I could see was a spot in front of my eye for ages  

Would also budget for a Video camera as it shows much more than the eye and can be seen by several people at once.

Dave

[glowingturnip]

Thanks for the tips guys, and to echo Gordon, I was hoping that you'd weigh in too, Olly.

Totally agree - the first time I sat down with the school to discuss the project, I started out with what they were expecting to get from it and use it for, in fact had exactly the same conversation about fuzzies - let's face it, even Andromeda isn't all that when observed visually.  This is why I'm concerned so much about going for the right focal length, and why I'm leaning towards that 10" Meade rather than the 12".

The crowd-pleasers for the kids (boys age-range 9-13) are going to be lunar and solar (from full disc down to detail), planets, and outside the solar system a few things like open and globular clusters which I always think look better visually than in photos, the odd binary star, the occasional comet, some of the planetary nebulae, orion,  but apart from one or two kids who really get into it, would agree that looking at a faint galaxy or nebula isn't going to hold the attention very long.  Too ealry to be thinking about lesson plans though.

I also think other good take-aways for the kids will be planetary webcam imaging since it's 'relatively' easy, and DSLR imaging of sun, moon - am even thinking how cool it would be to send the kids home with their own avi's of jupiter on a memory stick for them to process with dad (the teacher I was talking to seemed quite keen on the teaching aspects of explaining sigma-clipping...).  Also, I think that linking the scope to decent planetarium software running on a laptop in the dome would be really cool - very educational software, can run simulations of historic events, fly-bys and views from other planets, helps explain the mechanics of the movement of the sky and coordinate systems and shows how the constellations they're looking at are supposed to look - and then at the click of a button, you can make the telescope slew to the exact same target like a robot so you can look at it for real - how cool is that !

So, focal-length wise, I'd like something that will show a full disc sun or moon at the wide, down to a good view of the planets for webcam use.  If my calcs are right, a 2800m focal length will *just* fit a full lunar disc on a dslr chip with a focal reducer - going to have a look at eyepiece choices to make sure I can cover that range visually too.  I'm also suggesting they have a couple of pairs of bins in the observatory as well, for the boys who  are otherwise bored and waiting their turn at the eyepiece - objects like the moon, plaiedes and so on will be very accessible that way.  The bins are probably best locked away for daytime use.

Space doesn't allow for multiple mounts sadly.    Having a refractor on the rig too would be cool, but with a solar scope on there too, plus a guidescope, and all that would be missing is the death-ray !  Mind you, looking at the payload rating of that mount, we could probably sit one of the boys on the scope and still track to sub-pixel accuracy !

So with all that in mind, do we think the 10" Meade SCT (2500mm), or shorter focal length SCT (suggestions ?) or a really good refractor (suggestions ?) ?

Regarding solar, that is a specific requirement of the school, I guess so they can demonstrate usage during regular school hours, and it has to be in the dome, so I think solar Ha scope coupled to the main scope, and may as well have a white light filter for the main scope at the same time.  I've gone through the safety aspects with them, and they will certainly be doing their full risk assessments, as they have to do for all science experiments, DT work etc, and I'll be making sure as much as I can from my side that they are aware that the risks for solar could potentially be very high.  Lots of dire warning signs around the place (bearing in mind that future users of the equipment won't necessarily be the people using it now), specific safety rules and regulations the kids have to follow, I'm thinking put velcro over every lens cap so none can ever fall off by accident (regardless of how annoying that would be) and I like that suggestion of doing all solar imaging through the webcam, so that no kid would ever need to touch the scope during the day.

Please keep the comments coming, very much appreciated,

Stu

[perkil8r]

Avoid white light IMO, too many risks. One option I considered was to mount the solar scope back to front so that the main scope is pointing the wrong way when the solar scope is pointed at the sun.

As for why we have a 16", no idea, that's what they bought before I started there