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Ibbo!

Mercury Transit 9th May 2016

155 posts in this topic

Mercury Transit 9th May 2016

Warning The sun is dangerous and any mistakes could lead to permanent blindness.

The Geocentric Phase timings are 11-12 UT ingress(12-12 BST) 18-42 UT egress (19-42 BST) but your actual local timings will differ slightly. This website will provide additional information - http://eclipsewise.com/oh/tm2016.html

Preparation is king from the making of filters to the planning of the path of the sun from your chosen location, a tree of building in the way can make for a frustrating day.

The size of Mercury makes the use of eclipse glasses of no use so you will need some sort of telescope/binoculars to view the event.

Anything involving the sun is dangerous if you do not take the usual precautions.

The use of a proper filtration is of uppermost importance.

The filters are available from all reputable astronomical vendors and can be Baader film to the use of a dedicated solar telescope.

The making of a Baader film filter can be done as a Blue Peter DIY but please make sure that it cannot fall off and has no pinholes in it. The attached video explains the making of a suitable filter in more detail - http://www.bbc.co.uk/programmes/p014hpkh

All finders must be also be filtered, securely capped off or removed.

In no circumstances are the eyepiece filters to be used (usually sold on eBay) –they should be destroyed as a matter of course.

Imaging Ha filters again are not to be used for solar viewing or imaging.

If you are sharing the event please make sure that your visitors are aware of the precautions that must be taken with solar viewing.

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All ready Steve. Lunt Herschel wedge arrived on Wednesday along with a Baader solar continuum filter. Gave it a good test yesterday and was happy with the results. Much better detail seen when I compared it to my solar filter.

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Would not have seen anything if it had been today or yesterday, so need to remember that if May 9 turns out a cloudfest.

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Good luck with it laudropb, here's hoping we get a clear day.

 

Jim

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Hi there , I need some help in making an off axis solar filter for a C9.25. As you can see the resultant aperture is tiny. Would making multiple off axis areas around the central obstruction increase effective aperture and give a reasonable result?

image.jpeg

image.jpeg

image.jpeg

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Have you tried it?!

I'd make sure there's no way it can actually fall off whilst viewing.

If you don't want to tape it to the body of your 'scope, then strapping it on somehow might be safer.

The view will be fine.

I made a filter for my 8" dob that effectively stopped it down to 2" and it worked a treat.

I don't know about making multiple off axis filters though.

Someone will be along eventually if they do, if not, why not try it and see?

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I would like to have tried for this event, but as always it falls on a work day, and no way am i using a days leave in the hope of it being clear

good luck people and stay safe

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Do what I did Jules. I've booked the day off and told my manager why. If the weather forecast is looking bad the day before, I said I'll come into work and cancel that day off. He's fine with that! 

I've never viewed the sun before, and I ordered this filter yesterday https://www.firstlightoptics.com/solar-filters/astrozap-baader-solar-filter.html

Although a little apprehensive about viewing the sun, I can't wait to try it out!

And, living in London, this will be the first time I'm not hacked off with the light pollution! :)

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Hopefully I'm not breaking any rules by posting this link - the National Space Centre is afterall a not-for-profit educational organisation - and this appears to be the most appropriate section to post it:

Transit of Mercury Event at the NSC in Leicester on 9th May

http://spacecentre.co.uk/event/transitofmercury/

A section of the main car park will be cordoned off for use by astronomers who are happy to make their solar viewing equipment available to the public.

Edited by BlabyStarGazer

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12 hours ago, pblackwell said:

Do what I did Jules. I've booked the day off and told my manager why. If the weather forecast is looking bad the day before, I said I'll come into work and cancel that day off. He's fine with that! 

I've never viewed the sun before, and I ordered this filter yesterday https://www.firstlightoptics.com/solar-filters/astrozap-baader-solar-filter.html

Although a little apprehensive about viewing the sun, I can't wait to try it out!

And, living in London, this will be the first time I'm not hacked off with the light pollution! :)

A good plan but wont work with my job

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Emergency advice please folks!

I've just received a solar filter and on close examination I can see numerous tiny indentations. I've held it up to an inside light and can't see any obvious holes.

Is this normal and expected ? I've never attempted to view the sun and am worried.

I bought this , please advise me. Should I contact the seller or is this quite normal?

https://www.firstlightoptics.com/transit-of-mercury-9th-may-2016/astrozap-baader-solar-filter.html

thanks guys

Paul 

Edited by pblackwell

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2 hours ago, pblackwell said:

 I've held it up to an inside light and can't see any obvious holes.

Is this normal and expected ? I've never attempted to view the sun and am worried.

 

Hi Paul,

I've have only ever used  homemade  baader film filters prior to buying a Herschel Wedge, though I still have several in use for cameras as well as 'scopes.  I can only assume that by 'indentations' you are referring to small rucks or creases where the film is not stretched taut to produce a mirror like flatness (?).   If so, then there is nothing to be too concerned about.  My own filters tend to look like that too - a kind of exaggerated version of the image in the link that you posted.  Pin holes are what you need to worry about!  Holding the filter between your eyes and a ( lit ) lightbulb and checking carefully for holes (as you appear to have already done) is the way to check it.  If there are none, I wouldn't worry.  If there are, and the filter was purchased 'new' then it is covered under the Sale of Goods Act and will be replaced/refunded as faulty, but I would expect that to be VERY unlikely to arise.    It IS daunting, using a film filter for the first time, and it's good that you're being careful.  I remember being a bit sureprised when I saw my first film filter - i had expected it to be 'stretched taut' - but they're generally far from it!  Heck, I even got nervous the first time I looked through a Coronado Solarmax 'scope !!

 

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So long as there are no pinholes and no light leakage then you should be fine. These are two that I made today and they work very well.

image.jpeg

image.jpeg

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10 hours ago, BlabyStarGazer said:

Hi Paul,

I've have only ever used  homemade  baader film filters prior to buying a Herschel Wedge, though I still have several in use for cameras as well as 'scopes.  I can only assume that by 'indentations' you are referring to small rucks or creases where the film is not stretched taut to produce a mirror like flatness (?).   If so, then there is nothing to be too concerned about.  My own filters tend to look like that too - a kind of exaggerated version of the image in the link that you posted.  Pin holes are what you need to worry about!  Holding the filter between your eyes and a ( lit ) lightbulb and checking carefully for holes (as you appear to have already done) is the way to check it.  If there are none, I wouldn't worry.  If there are, and the filter was purchased 'new' then it is covered under the Sale of Goods Act and will be replaced/refunded as faulty, but I would expect that to be VERY unlikely to arise.    It IS daunting, using a film filter for the first time, and it's good that you're being careful.  I remember being a bit sureprised when I saw my first film filter - i had expected it to be 'stretched taut' - but they're generally far from it!  Heck, I even got nervous the first time I looked through a Coronado Solarmax 'scope !!

 

Thanks Paul,

Yes the film has creases, but what I did notice were some tiny 'blemishes' or indentations so that's the concern. I've emailed the seller asking is this normal and will wait for their response. Lets see.

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I make my own filters out of cardboard and Baader Solar Film, just with an off-axis hole about 3" diameter in my cardboard mask at the front of the scope, and I can still see to write this!

But, just in case... After doing all the above checks about holding your mask to a very bright light and checking for pinprick holes etc. etc.

... when I put it on the scope I always take the first look with my weak eye (in my case the left)... just in case...

Too much panic-mongering about this I think!

BUT... DON'T FORGET TO MASK YOUR FINDER OR COMPLETELY CLOSE IT OFF!

It's instinctive for most of us to keep having a peep in the finderscope. This is where it could go badly wrong.

My tuppence worth, Phil.

 

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Here's Baader's own online instructions. They worked for me, and believe me, I'm no genius at DIY.

http://www.baader-planetarium.com/sofifolie/bauanleitung-objektivfilter-en.pdf

(German web address but English text version)

The most useful tool to go with them is some school geometry compasses, and make sure the card you use is heavy-duty enough.

Edited by Expat_tony

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Hope this is the right place for my post


So with the 9th of May approaching I want to try the following

add a solar filter to my Skywatcher Explorer 250 

Add a camera instead of the eyepiece and then via the laptop project onto a flat screen in the club house so members of the public can see it in total saftey

So a few questions

1 - so the skywatcher cover has the removable 2 inch cap and reading online it seems for the sun this is the best approach, leave the cover on and have a filter over the smaller hole - can I buy a premade cover for the 2 inch hole

2 - Cameras - I have a choice of QHY5, QHY5 II or an oldder Philips Webcam spc900nc - any thought on which would be the best to use ?

3 - What software would be most appropriate for this project


Thanks in advance


John B

 

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Yes that will be enough film - You can make a "small aparture" filter for your 400mm lens (maybe 100-120mm will be big enough).  Make a film holder for both lenses of your binoculars to prevent any risk of an accident.

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2 hours ago, BinocularSky said:
This is why you should never use plain glass Eyepiece-fitting Solar Filters

Ouch!

I was wandering if projecting the sun with 10*50 bins would let me see mercury? I've already ordered a £5 pair from ebay, so I hope it will work.

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36 minutes ago, Joe12345 said:

Ouch!

I was wandering if projecting the sun with 10*50 bins would let me see mercury?

Yes, it will, but be careful if there are any plastic "internals"; the heat can melt them. (Guess how I know.)

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I would personally prefer putting Baader film over the objectives of the 10x50s. Safer

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Regarding imaging the event, I think I have settled for a dual scope set-up, imaging the sun in Ca-K with the 80mm F/6, and using my ST80 guide scope with Herschel wedge and Solar Continuum filter (plus IR block). The narrow band of the SC filter will remove all chromatic aberrations. I will either swap the ASI174MM from scope to scope, or attach the ASI174MM to the Ca-K set-up, and the ASI224MM to the ST80 WL and use two cameras. I will see if running two instances of FireCapture gets me into trouble. If so, I will just use two laptops

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I'm not planning on imaging the event, but its such a long event that even for me as a non-astro imager there is plenty of time to take things slow on the day and attach my 450D to the scope/wedge and experiment without being rushed or getting flustered. 

I'd absolutely no interest what so ever in the Venus transit. I wasnt convinced that watching a little black dot cross the solar surface even counted as astronomy. I had never even done any solar observing at that time either.

I'm into this transit, but wont be watching it start to finish. If there is a nice sunspot or grouping which the planet may intersect during transit........that will be worth watching/imaging.

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