Saturday, May 19, 2012

Sunspots on screen

See the initial post.

It took a little bit of work and twiddling with the cheapy $20 telescope ( which is probably an excellent seismometer since it shakes with my heartbeat if I am within 5 feet of it!).

Since a telescope is designed to focus a virtual image on your retina with the help of a third lens (your cornea), in order to use it as an effective real image projection device (without setting the screen on fire!) the eyepiece has to be removed completely and held just outside the tube.

 I've just realised that the 90 degree reflector for the eyepiece may give me that added distance!

Cut and install a screen around the objective side of the telescope to provide a dark back ground for the sun's image. Note that the spotter scope is rendered useless.

So you can insert a long tack or pushpin from the back of the screen to use as an aid in alignment.

Or just use the shadow of the body of the telescope. In the following photo the telescope is NOT aligned.

Ready for the ...
... lead astronomer.
You can see the sunspot groups: a streaky one angled towards 630, at 9 o'clock, half way out, and a second one at 8 o'clock about 2/3rds of the way out.

Since this image is taken at sunset, in this photo the sun's North pole is at about 9 o'clock, as is confirmed by the rotation of the sunspots that Maya and I have observed over the last two days.

In the first observation two days ago, the lower sunspot was just above the 9 o'clock radial, both were in the top left quadrant.

Not a bad hack!

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