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Compare the full disk images on 2003/10/30 and 2003/06/08 below. Do you notice the Sun is larger on 2003/10/30? -- It can not fit in the frame. I used the same telescope, eyepiece/adaptor, the same focal length (widest zoom) on the camera for the two photos. It turns out that's because the Earth is closer to the Sun on 2003/10/30 than on 2003/06/08. As a result, the visual diameter of the sun is 1933" and 1891" on those days respectively. But why? Because the orbit of Earth is an ellipse. We are farthest from the sun around July 4th every year (aphelion), and closest around January 4 (perihelion). The sun's diameter is about 1888" and 1952" on these extreme dates. Is it significant? in my set up, that translates into a full solar disk of about 1497 and 1549 pixels respectively. My digital camera has a typical frame height of 1536 pixels. The bottom line: I can take full solar images in summer, but not in winter!

Sunspots 2003/10/30 10:52 EST
Sunspots 2003/10/30 10:52 EST
2003/10/30 10:52 EST. The two major groups of sunspots are 486 (above) and 488 (below) respectively. 8"/f6 Dob, Baader Astrosolar filter, Scopetronix 18mm eyepiece/adapter, Nikon Coolpix 995 camera. Sunspot 486 produced strong aurora activities across north America, see my aurora photos from Pittsburgh that night .

Sunspots 2003/06/08 14:58 EDT
Sunspots 2003/06/08 14:58 EDT

Sunspots 380, 03/06/08 15:05 EDT
Sunspots 380, 03/06/08 15:05 EDT
Sunspots 375, 03/06/08 14:57 EDT
Sunspots 375, 03/06/08 14:57 EDT

2003/6/8 15:00 EDT. Sunspots (from left to right) 380, 377, 375, and 373. 8"/f6 Dob, Baader Astrosolar filter, Scopetronix 18mm eyepiece/adapter, Nikon Coolpix 995 camera. Photos taken in cloud gap, seeing was not great.

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All images by Jerry Xiaojin Zhu unless noted otherwise. Feel free to use them for your personal enjoyment. For other usage please contact the author at jerryzhu@gmail.com