Today, the Astropotamus went 8 minutes and 14 seconds into the past and looked at the sun through a solar safe filter on the Time Machine. What did he find? Sunspots! 2013 into 2014 is expected to be the period of maximum sunspot activity in this, Cycle 24, of the sunspot cycle. But today, there were at least five clusters of sunspots dancing across the face of our nearest solar neighbor!
I sketched what saw in my brand new astronomical sketch book. This was the first time I’d ever made astronomical sketches and was quite pleased with my art work. Later, kicking myself for not thinking of it sooner, I got the camera out and the new T mount adapter that came last week and hooked the camera up for direct focal plane astroimaging of the sun. This means the Time Machine was the lens of the camera. The Time Machine is approximately a 2000mm f/11 lens, and the camera is a DSLR, so that’s an effective 35mm equivalent lens of about 3000mm. So the sun occupied about 130% of the field of view of the camera and only the swath with the spots was imaged.
This was the first time I’d done focal plane astroimaging, so it was a learning experience both for how to do it in bright sunlight and how to use this camera for this purpose. In the end, the images weren’t 100% properly exposed nor 100% properly in focus, but a little work in front of the computer managed to bring out a bit of detail.
Nine images in particular were chosen to have some processing done to bring out the spots. I want to do some stacking later, but didn’t have the time today. I put this one up for you to look at. You’ll see a black and white version of the sun that’s been masked to a perfect circle. This is for ease of image processing. A series of clusters forms something like an island chain from the middle top of the sun heading towards the right and down towards the middle. Ignore the circle looking dots in the bottom quarter or so – these are dust on the Time Machine’s lens.
The sun moves pretty quickly through the sky – basically 360 degrees in 24 hours, or a quarter of a degree per minute. Since the Time Machine has an estimated 1/3 of a degree field of view in this configuration, that means that the sun moves through the field of view on the eyepiece in about 80 seconds. When you’re trying to stay still and take pictures that you can’t really see because it’s too bright to get critical focus details and you’re bracketing everything like crazy and using a 2 second self-timer to help eliminate camera shake when smashing the button, it can be difficult to get anything useful at all. So I’m actually quite pleased with the results.
Five clusters of sunspots starting at about 12 o’clock and heading towards 3 o’clock. The cluster on the far right is only a single spot while the others are clusters of sunspots. Click the image for a larger view.