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JOC

Request for support/advice - Solar Outreach

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Posted (edited)

Thought I had better post here to get the best solar advice.

As you know I am a STEM Ambassador and I have volunteered for our local street science fair in a few weeks time.  They like us to take an 'activity' if we have something that is cheap and suitable for demonstrating in a busy outdoor shopping center.  The theme this year is 'space'.   For a moment this floored me then like a shaft of light I remember that socking great big object in my porch - my telescope!

Problem is that it's a daytime event.

So could I please run the idea past you solar experts and get your thoughts as an outreach activity.

I have a home-made solar filter that I made from that expensive solar film.  I keep it in a special box so it doesn't get damaged and it fits the whole 8" OTA - I attach it via some small bungee cords and always check it for pinholes prior to use.  I also have a dark shroud which fits around the flex tube rods to keep out stray light and have also invested in a solar 'shadow' finder.   I have some cheaper EP's BST's etc. of a suitable magnification.  If I can get to power (possibly via my own battery box or if they can lay on power for me) the Dob will also solar track.  

Bearing in mind that is only a home-made filter (though I took a lot of care making it) - would the above kit be suitable for outreach supervised solar viewing if I was willing to take the scope along for use (which I am)?

If not would anyone be willing to loan me the kit that would make the telescope suitable?

Assuming the homemade filter is OK, I'd need to tell people what they were looking at - these silver backed sheets must filter to a given band-width, I see folks talking about different types of solar viewing could anyone enlighten me as to what this Baader solar film with the silver back views in.  I see a big orange disc when I look through it.

Also, I have to contend with the fact it could be cloudy - if this is the case, whilst the telescope is interesting in its own right to see, if anyone could send me some solar pictures taken with 'backyard' telescopes that they would be willing to let me print out and show as to what is possible it would give me something to talk about if the sun didn't make an appearance.

Also, is there any chance of an appearance by a daytime moon on Saturday 13th July in the South East UK?   I don't know how you find this out.

Basically, what do you think of the idea - if the theme is space would a look at our own 'star' count do you think?  All input would be welcomed as would any other ideas that I could afford and would be safe to put on in a busy outdoor shopping area.

 

Edited by JOC

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I see no reason why your homemade filter shouldn't be used to demonstrate white light solar provided that you state all the normal warnings that the scope is fitted with a specialist filter which reflects 99.999% of the sun's energy (according to the Baader website) and that under no circumstances should the sun be observed without specialist equipment, etc. 

You could demonstrate the checking process you go through before observing to make sure everything is securely in place.

I can't help with images I'm afraid as I'm visual only but a mobile or tablet could be used to access images via the Web. 

With regards to a daytime moon, the LunaSolCal app gives a moonrise time of 18:17 for my office at Fareham in Hampshire on 13th July so I guess that will unfortunately be off the cards. 

I quite often give impromptu solar sessions when people stop to ask what I'm doing when I'm solar observing at a public place, I'm just really cautious about giving the warnings and making sure that they fully understand that the telescope is fitted with specialist equipment to make safe observation possible. 

I observe with a Frac and my Lacerta Herschel Wedge makes it easy to demonstrate how the Herschel wedge gets rid of most of the energy onto a heat sink as its open at the bottom and the disc can be seen on the inside face of the heatsink as can all the bleaching of the black anodising. 

Hope this helps, 

Ade

 

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I would recommend a few ideas to consider...

Taping the filter down so that it can't come off by mistake.

Always having a look through the eyepiece yourself just before each new punter has a look.

Try to set up the space so that you can't be crowded with lots of people around you such that you can't keep everything safe.

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@AdeKing  That's very good news and advice - thank you.  If I can use the telescope it means I won't have to invent anything else to do.  I can make lots of posters about precautions and put stickers all over the place and tell folks about safety precautions so they don't back home and try it, but I bet (if we get a sunny day) that lots of people might be interested in looking at their local star - thank you for the term 'white light solar' too 🙂

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1 minute ago, Paz said:

Taping the filter down so that it can't come off by mistake.

Always having a look through the eyepiece yourself just before each new punter has a look.

Try to set up the space so that you can't be crowded with lots of people around you such that you can't keep everything safe.

I'll take a reel of duct tape - good idea

Good idea to check the view too and maybe a queue here sign would be a good idea 

Thankyou!

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27 minutes ago, AdeKing said:

With regards to a daytime moon, the LunaSolCal app gives a moonrise time of 18:17 for my office at Fareham in Hampshire on 13th July so I guess that will unfortunately be off the cards.

That's a shame, but thanks for checking for me I guessed someone would know how to find out.  I know sometimes I have had a good look during the afternoon.

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Sounds like a good opportunity, no reason why not to do it providing you follow the plan you've outlined.

A couple of thoughts/points. Sorry if this is stating the obvious, but the term White Light Solar means you are looking at the whole spectrum, not filtering on one specific frequency. The film just reduces the intensity across the board.

You could use a UHC or OIII filter if you have one, it can help bring out the features a little more.

That brings me on to the main negative, and that is the quietness of the sun currently. There are unlikely to be any major active regions visible, so you may be limited to some granulation and faculae if visible. Perhaps print off some images with major features labelled up as backup too.

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4 minutes ago, Stu said:

the term White Light Solar means you are looking at the whole spectrum, not filtering on one specific frequency. The film just reduces the intensity across the board.

Ah, OK - I didn't have a full understanding, but with this ^^^ explanation I will be able to explain what people are looking at - I don't think people will really know the difference (unless they are themselves experts - and there will always be at least one!) I think they will probably just be in awe of the fact that they can look at the sun when they normally can't.

9 minutes ago, Stu said:

You could use a UHC or OIII filter if you have one, it can help bring out the features a little more.

I actually have both of these available perhaps I have missed the obvious trick that I could add a filter, I guess, to the EP side of things?

 

13 minutes ago, Stu said:

There are unlikely to be any major active regions visible, so you may be limited to some granulation and faculae if visible. Perhaps print off some images with major features labelled up as backup too.

This is going to need some research - I am not a solar expert (well I'm not even an expert astronomer - I'm just someone that owns a telescope).   Knowing my lucky it will be cloudy anyway - so I might just be limited to explaining how a telescope works - perhaps I ought to take the little refractor as well as a contrast if it looks like being cloudy.

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Solar is good fun, but obviously rather weather and solar activity level dependent!  I've done it quite a few times with a Ha scope and with white light for a different 'view'.  I've tended to use a music analogy for the different filters.  White light is just like turning down some very very loud music so you can actually hear all the music together, while Ha is like saying I want to hear the vocalist over the bass player and drummer, so I exclude the lower frequencies and just include the higher frequencies.

Here are some documents that might help - prepared mostly for the outreach stuff we did for the 2015 eclipse (hence the dates on the matching pictures!).  If you want the original publisher files just PM your email address 🙂 

I've found stickers are always popular - if you use standard address labels (18 per page work well) then they are easy to print.  I usually get kids to reiterate the safety warning before giving them the sticker!

Your refractor might be easiest.  You could knock up something like this https://eclipse2017.nasa.gov/make-sun-funnel - I can supply the projection material too (minimum order quantity was way above my need!)

This site http://www.solarham.net/ is great for seeing what is happening (or not!) on the sun.

Hope that helps a bit

Have fun!

Helen

PS make sure you log the event with STEM ambassadors beforehand to ensure your insurance is covered.

Different Lights.pdf Matching answer sheets.pdf Solar Facts-K.pdf

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@Helen & @Mark at Beaufort what great resources thank you both.  @Helen I'll drop you a PM with an email address in if I may, it won't hurt to have to have the originals in case I want to print the images onto separate pages.  I knew SGL wouldn't let me down.  I don't know if I can make one of those funnels as I am not certain if my refractor has any plastic within it or how I'd be certain that a EP didn't either.  It seems somewhat more fraught with 'melting' type danger to let the light into a telescope light path without sufficient protection at the light inlet end.  It is a very specific shape of funnel too - I'd have to find one similar in dimensions, but it is a neat idea and I can see the potential.

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If you need any images I have one you can use ... Its not special but it is our star and taken with amateur equipment, and an ameteur bloke 😀  

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1 hour ago, knobby said:

If you need any images I have one you can use ... Its not special but it is our star and taken with amateur equipment, and an ameteur bloke

Anything to brighten the stand will be useful, thankyou!

3 hours ago, Helen said:

PS make sure you log the event with STEM ambassadors beforehand to ensure your insurance is covered

I am actually responding to to a STEM Ambassador request and will be part of their own stand so that should be covered, but yes it's a good idea to check that the computer has got a log for the event beforehand for me, though often my group will add them for us.

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Perhaps you could make a solar pinhole camera as well?  That sort of thing wouldn't be too hard to reproduce at home and there must be loads of instructions on the web for how to make one.

James

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24 minutes ago, JamesF said:

Perhaps you could make a solar pinhole camera as well?  That sort of thing wouldn't be too hard to reproduce at home and there must be loads of instructions on the web for how to make one.

James

There is an article in the July Sky at Night magazine about making Astro interesting for kids. One of the suggestions is a projection box that you put partially over your head to view a projection of the sun. 

Might be worth a gander. 

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3 minutes ago, AdeKing said:

There is an article in the July Sky at Night magazine about making Astro interesting for kids. One of the suggestions is a projection box that you put partially over your head to view a projection of the sun. 

Might be worth a gander. 

That sounds like it could be fun.

James

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Posted (edited)

I found the projection box with the large grocery box online, I guess the larger size makes the image a bit bigger, but in terms of making something practical for most people I did like this one:

Making a pinhole device is not something I've ever done, but this cereal box design seems so simple.  I assume these things work?    I see the implications of providing advice, but it would be good to send children away with something they could do at home and this design seems quite achievable.  I could do like a Blue Peter thing do some demo models showing how it is constructed and do a printable to send the kids away with.  500 cereal boxes and I could send every kid home with one, but this might not be possible, but they might make one themselves - I could add all the usual stuff about getting adults to help with sharp things and in their use.  One thing I've often wondered with pinhole things is how is focus achieved?  All these things have a projection plate, whether a large grocery box or cereal box device, but as I see things all the focal lengths are a bit different (though given the huge distance from the sun, I guess, relatively, not by much).  Sorry for the novice question, but I'm interested in how they all reach focus?

Edited by JOC

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I think a little experimentation may be required to get the pinhole size right, but once it is then the camera is effectively always in focus.  At least, that's my understanding.  I'm unable to explain why this is the case however :(

James

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32 minutes ago, JamesF said:

I think a little experimentation may be required to get the pinhole size right, but once it is then the camera is effectively always in focus.  At least, that's my understanding.  I'm unable to explain why this is the case however :(

James

Some info here which is useful.

https://electronics.howstuffworks.com/question131.htm

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Hi @Stu so just the effect of 'All of the [light] points in the scene do that at the same time, so an entire image, in focus," [appears on the focus screen] arriving at the back of the screen is sufficient to make image in focus.  I guess the size of the hole and therefore the overall angle the light can enter then becomes important.  The smaller the hole the smaller the angle the light can arrive at the back of the box and so the angular distances are all pretty similar and image is in focus?

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6 minutes ago, JOC said:

The smaller the hole the smaller the angle the light can arrive at the back of the box

That's the key point, the smaller the hole, the few possible routes there are for the light from any particular part of the scene being imaged to take to get to the film or projection screen. The trade off is a dimmer image though. I guess the smallest hole and the darkest viewing 'space' are the key things to get right.

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At our outreach events we are often asked how many stars can be seen with the naked eye. The true answer is one, the Sun during the day. All night time stars are far too remote to be seen physically, all we can do is see where they are and even that isn't really current due to the time their light has taken to reach us.   😀

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21 minutes ago, Peter Drew said:

At our outreach events we are often asked how many stars can be seen with the naked eye. The true answer is one, the Sun during the day. All night time stars are far too remote to be seen physically, all we can do is see where they are and even that isn't really current due to the time their light has taken to reach us.

I like that, I'll have to remember that one. 

Gulp!  I've just found out that a proper 'astrophysicist' is coming as a volunteer as well.  If I take along the telescope they will soon know that I am out of my comfort zone!

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1 minute ago, JOC said:

Gulp!  I've just found out that a proper 'astrophysicist' is coming as a volunteer as well.  If I take along the telescope they will soon know that I am out of my comfort zone!

It's not impossible that you know more about practical astronomy than the astrophysicist!

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11 minutes ago, Stu said:

It's not impossible that you know more about practical astronomy than the astrophysicist!

Not impossible, but unlikely - I still count myself a relative novice when it comes to telescopes and doing stuff, to the point at which I am still amazed when the experienced participants on SGL will still give me the 'time of day' with some of the iffy stuff I must post.

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