AST 195 PROJECT (Hybrid & On-Line classes)
Observing the Sun with a Solar Filter

Click here for the cover sheet.

In this project you will observe the sun and look for sunspots.

First, you need to see if there are any sunspots to observe. Click here to go to the Solar & Heliospheric Observatory image page and see if there are any sunspots visible. If there are, and if it is sunny outside, then you can do this project. (If there are no sun spots—and sometimes there are not, depending on the sun’s cycle—you can still do an observation, but you should try to get some sunspots in at least some of your observations.)

Keep in mind you need a properly constructed solar filter to do this project. The filter material must fully cover the aperture of your telescope, allowing no unfiltered light into the telescope.

The unfiltered sun can roast an eyepiece quickly, so think of what it will do to your eye. Viewing the sun is safe if done properly and carefully. If you have been sloppy in the construction of your solar filter, or if you have been careless in caring for it, etc., you can hurt your vision.

In short, if you are not ready to take the time to carefully prepare for this project and perform it with the proper care and respect, then take a zero on it.

Prior to beginning your observations, you must watch the video on how to find the sun, and submit a completed “Pre-observation safety check sheet” for approval. Do not observe the sun until you receive approval.

If you are willing to use proper care and respect, and you have submitted the safety check sheet and been approved, you may attempt solar observation on your own. Observing the sun can be very enjoyable (if the sun is active and there are sunspots to see).

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· Click here for video on how to find the sun with your telescope.

· Click here for “Pre-observation safety check sheet”. Complete this sheet and submit to your professor for approval prior to observing the sun. Your professor will then sign it and return it to you, prior to you observing the sun. Once you have the safety sheet signed by your instructor, you may commence solar observations. Students who complete this project without completing the safety sheet and obtaining the professor’s signature prior to commencing solar observations will not receive passing credit for this project.

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After your safety check sheet is approved, you may commence observing the sun. When observing the sun, do the following:

· Before attaching the filter to the telescope, hold it up to the sun and look through it to inspect for defects, holes, or other flaws that will allow unfiltered sunlight to enter the telescope. You should be able to observe the sun through the filter with ease. If there are defects, holes, or flaws, do not use the filter.

· Find the sun and focus the telescope, as in the video.

• Draw the sunspot groups that you see. Use the drawing sheet from the class web page. Make your drawing before taking any photos. Photos typically will not show all that you can see with your eyes.
• Take a photo through the eyepiece.
• Click here to go to the Mt. Wilson Solar telescope’s daily drawing of sunspots. Make sure that their drawing is for the same day as you are making your drawing (if they have not posted the drawing yet, the drawing they show could be for a previous day). Print out the Mt. Wilson drawing.
  For an archive of daily sunspot drawings, going back decades, from Mt. Wilson click here. Some alternative sources for daily sunspot images are—
  [1] the SOHO (Solar and Heliospheric Observatory) satellite (click here), which also has as archive of images (click here).
  [2] The SOLARHAM sunspot data page (click here), which has an easily searchable “Visible Disk Archive” that allows you to see the sun as it looked at different dates.
  [3] SPACEWEATHER (click here), which also has an archive of solar images.
  The Mt. Wilson images show more detail, however, and are preferable, but Mt. Wilson is old and losing funding so I’m not sure how much longer data will be available from there. SOHO is getting old, too.
• Do this for three different days. No two days should be any less than three days apart (so Monday/Thursday is OK, but Monday/Tuesday or Monday/Wednesday are not).
• In a few paragraphs (typed), compare your drawings to the Mt. Wilson (or other source) images. Discuss how you did, what you noticed about the Sun, and what you learned.

Turn in:

§ Your approved “Pre-observation safety check sheet”.

§ Your three drawings.

§ Your three photos (make sure the photos are dated and have your name on them).

§ The accompanying Mt. Wilson drawings (or alternate source images—SOHO, SPACEHAM, SPACEWEATHER).

§ Your typed discussion.