Sunday, August 13, 2006

Sunspot 904 - Without Optical Aid

20060813 sunspot 904image credit:

After an all nighter on Saturday, Charlie and I observed sunrise. He brought his solar filter but I had forgotten mine. He mentioned how large 904 was and he mentioned that they could be large enough to observe naked eye. The sky was too clear to observe the rising Sun without any filters and he had already attached the filters to his glasses. We observed sunspot 904 in his Canon 15x bins.

So today my plan for a brief observing and sketching session of the sunspots. Holding the Baader film filter to my eyes I could see both spots in the lower left part of the solar disk, no magnification required. The larger one was obvious, the second smaller spot was not so easy but I suspected it.

Susequently, I setup the Tak bins with the Thousand Oaks solar filter for a closer look. The larger, westward spot has two large dark umbrae surrounded by an irregular penumbra. The smaller, eastward spot also consists of two umbrae surrounded by irregular shape penumbra. Each penumbra has a "taffy pull" towards the other. This is evident in the image provided by

Returning to the unaided view after using the bins, I could see the second spot with more confidence a bit to the right and higher.