Make a Wall Mirror Observatory for Backyard Astronomy

[JB80]

Well this is quite quaint to say the least, certainly an interesting concept and if nothing else it is a bit of fun.

The premise of this being to basically grab an old wall mirror and take it outside and rest it on a table or somewhere flat and instead of craning your neck looking upwards(lol hard I know) you can grab a pair of bins and look at the stars in the mirror on the table.

http://www.instructables.com/id/Make-a-Wall-Mirror-Observatory-for-Backyard-Astron/

No idea of the practicality of this for the serious observers but it would at least be a great focal point for a night time get together with friends.
I would also imagine that this really needs to be covered during the day as it could be a potential fire and aircraft hazard. Still we have a mirror I may be able to utilise. 

Like I say just a bit of fun.

[MAN or ASTROMAN]

What a wild idea,and according to a comment on the linked forum,it works!

Similar idea to the mirror projectors or whatever they're called that are commercially available-but a whole lot cheaper!

It's just Daft enough to try out one night-Just hope the Wife doesn't notice that the Mirror has gone AWOL.............

[Cornelius Varley]

It's an interesting idea, although it does have it's drawbacks. Normal mirrors are silvered on the rear of the glass and then a covering is applied to the back to protect the coating. Any light reflected from the silvered side has to pass through the air/glass boundary twice before reaching the binoculars which will tend to distort the image. Designs for front surface mirror binocular mounts are available on-line. http://www.craigcolvin.com/astronomy/binocularmirror.html

[JB80]

Good point, definitely not without it's draw backs but it's a daft enough idea to try.

I reckon it could be a good thing for meteor showers possibly, presuming it does actually work. I'm keen to try it but at 80% humidity at night it will have to wait.

[xtreemchaos]

hi Jarrod, ive thought about a mirror for solar as i have to do my daytime  watching from indoors due to Lupus and i have sutch a short time before sol gos out of range, theres a few things that bother me, would i beable to focus? would i have to motorise the mirror? and is there any danger to me or my scope?,motorising wouldnt be a problem as i used to build custom motorbikes for years and still have all my gear so i could soon weild something up.. i would love some advise on the focus and any possible danger from anybody. charl.

[JB80]

Hi charl, it is possible to do something similar with mirrors and solar projection where you reflect the suns light back onto a piece of card/paper/wall. The focus thing is quite easy as all you need to do is move the distance between the mirror and bit of card you are projecting it to until the image gets nice and sharp.

These links may help in explaining and visualising it better than I can.

http://www.eclipse.org.uk/old/pparc_web/mirror.html
http://www2.eng.cam.ac.uk/~hemh/transit.htm

I'm sure with a bit of gumption you could knock up a rig that will work.
Not sure if it is the kind of thing you mean though. But aside from that the usual advice about mirrors and sunlight being a potential fire danger if you are not careful and to absolutely never look at the sun in the mirror itself and only the projection itself, reflected light can be quite hazardous.

Hope that helps a bit.

[xtreemchaos]

thanks Jarrod, this is the setup i was thinking of- my ed80 looking out my obsy room window "with solar film or H Wedge" which is on the second floor of my house, to a mirrow about 50 feet down the garden which would be setup to track the sun, havnt a clue if it would work and ive never heard of anybody doing it, dont know if the frac would focus and the mirror would have to have to be good qual. thanks for the imfo links mate,charl.

[Peter Drew]

All of this is perfectly doable. I use a front surface mirror unit for comfortable overhead night time viewing in conjunction with a fixed 102mm refracting binoscope. The same setup can be used for solar observation provided that the objectives are suitably filtered. I also used to have a fixed refractor fed by a driven flat mirror, this is essentially a sideriostat. The mirror needs to be a good quality first surface component mounted equatorially. The drive has to be half sidereal rate as the mirror reflection doubles the solar rate. Best to keep the distance between the telescope and the mirror to a minimum to avoid vignetting. The mirror is flat so there is no focus and therefore no heat greater than the ambient sunlight. 

[xtreemchaos]

thanks for the imfo Peter,i will have to draw a plan up, and let you have a look, im glad it possable cos had the idea floating about in my head for a while, ever since watching sir Pats  The Sky at Night 1982.The Unfolding Universe. he showed a rather interesting telescope at kit peak in the states with a large mirror at the frount . charl.