Explore the Universe - Sunspots

This will be the first blog entry on our home star -- The Sun.  The Explore the Universe certificate only has one item related to the Sun -- Sunspots!  Observing the Sun should be done with extreme care, an untrained observer may permanently damage their eyes.  There are several ways to observe the sun with the most common methods listed below:

1. Projection of the Sun through a pinhole in a piece of cardboard onto a screen.
2. Full aperture filter for the telescope.
3. Special certified glasses designed for safely viewing the Sun.
4. Hydrogen Alpha Telescope (thousands of dollars for small aperture).

An eyepiece filter for a telescope should never be used as the magnified radiation from the sun may crack the filter causing irreparable eye damage. 

To project the sun you simply need two pieces of thin cardboard, the kind on the back of notepads.  Make a tiny hole in one of the pieces and hold it up so the sunlight goes through the hole.  Take the other piece of cardboard and hold it behind the first piece so that it acts like a screen.  By changing the distance between the two pieces you can project the sun into focus and see sunspots or a solar eclipse. 

Some people project the sun through their optical equipment such as binoculars or a small telescope onto a screen.  I honestly do not like the idea of concentrated solar radiation bouncing around inside expensive equipment, so I do not use that method.

I have a full aperture filter for my telescope that I use to view the sun.  The sun can be magnified and the sunspots scattered across the surface can be observed in detail.  Lately, however, the sun has been very quiet and has had very few or no visible sunspots.  Below is an image I took with a cell phone at the eyepiece of the telescope.

Sun with Sunspots