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Stargazing Observing the sun with Newton telescope

  1. Jun 28, 2011 #1
    While making a projection of the sun on a paper with a Newton telescope, I’m able to see a white ball or to make burning holes in paper.
    My idea however is to be able to see something more spectacular , like sunspots or protuberances.
    Does someone has an ideas how to do this practically?

    Thanks,
    Alain
     
  2. jcsd
  3. Jun 28, 2011 #2

    Drakkith

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    You can either buy a solar filter to cover the APERTURE of the telescope (Do NOT buy ones for eyepieces) or you could try covering the aperture with a sheet of cardboard or thick paper with a cutout that is very small. This will let less light through to the mirror and reduce the brightness of the sun. Be VERY VERY careful and never look directly into the eyepiece if you do it yourself.

    Without a cover or filter your telescope is acting like a magnifying glass and focusing huge amounts of light onto a small spot. Just like I used to do as a kid to those pesky insects with my magnifying glass....
     
  4. Jun 28, 2011 #3
    Again, you need to get a solar filter to cover the aperture (never EVER buy ones for eyepieces). You can get several different filter spectrums to get different images of different things (the most common is Hydrogen-alpha). I suggest using a filter instead of a cover if you want to see things like solar flares, sunspots, and solar prominences.
     
  5. Jun 29, 2011 #4

    ideasrule

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    You don't need a solar filter for projecting the sun's disk. First cap the finderscope, because you don't want to accidentally look into it, or have it focus sunlight on your skin. Then point the telescope at the sun, hold a piece of paper in front of the eyepiece, and move the paper so that the sun's disk is about 20 cm in diameter. Turn the focus knob unless the edge of this disk is as sharp as you can get it. If there are any sunspots, you should be able to see them. However, the sun is taking an unexpectedly long time to get out of the last solar minimum, so the surface is pretty much blank: http://spaceweather.com/

    Note that the projection method is only safe with small aperture, open-tube telescopes. Don't use it with a large Newtonian, and don't use it with a Schmidt-Cassegrain of any aperture. Heat might build up and permanently damage the telescope.
     
  6. Jun 29, 2011 #5
    @ideasrule: he used the projection method, but wanted to see something MORE SPECTACULAR, like sunspots and prominences.

    -cpman
     
  7. Jun 29, 2011 #6

    russ_watters

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    You can see sunspots with the projection method without a filter, as long as the scope isn't too big and the image too bright.
     
  8. Jun 29, 2011 #7

    Drakkith

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    Yeah, I'm assuming that was the problem for the OP. He had a scope that was gathering too much light from the sun, washing out any details.
     
  9. Jul 3, 2011 #8

    davenn

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    to see prominences you need specific solar filters they cost lots !!!

    I have done eyepiece projection with my 8" F5 Newtonian for many many years drawing sunspots. I would stop the opening down to ~ 3 - 4 inches.

    cheers
    Dave
     
  10. Jul 3, 2011 #9

    George Jones

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    Yesterday, I saw a prominence with

    http://www.meade.com/product_pages/coronado/scopes/pst.php [Broken].

    My astronomy club has one of these, as do a number of the individual members.
     
    Last edited by a moderator: May 5, 2017
  11. Jul 3, 2011 #10

    davenn

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    hey George

    yeah my dream acquition for solar observing, one day when I win the lottery :)

    cheers
    Dave
     
  12. Jul 23, 2011 #11
    I have not a focused image of the sun. Does someone has experience if i could make some sort of pinhole-camera/camera-obsura , to put behind the eyepiece of the telescope?
     
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