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Tuesday, June 05, 2012

There's a Little Black Spot on the Sun Today

Transit of Venus today. Here's a big pile of info. This post will be updated, if possible, with bad photos.

UPDATE 23:08 UTC: Here's another NASA site, with what looks like more info. They're doing a live webcast from Mauna Kea, where it's clear. Clear on Haleakala too. Here's a link for pictures from there. It's not quite so live (that I can see).

It was cloudy when I got up, then it started to clear, then it clouded up again. A few minutes ago the sun peeped out for about 30s. "Tag! You're it!" It does this to me all the time. Usually it's clear on the south coast, but it looks a bit cloudy right now. If I must I'll drive down there later.

AFTER ACTION REPORT: OK! This post should be subtitled "The Triumph of the Will," because the pictures represent the triumph of obstinancy over equipment, skill, and Nature. Just after 3pm local time I decided that the clouds were not going to part anytime soon, and it was time for a road trip. It was sprinkling when I left. Drove down to the beach. When I opened the car door the wind nearly ripped my arm off. Well, this will be fun.

But I managed to find a sheltered spot and got some decent pictures, considering. First, here is an illustration of my sophisticated astrophotographic technique:

Kibitzer Cat is optional.

The expensive filter there was a solar viewer given out for free by the U. of Hawaii. No eyes were harmed in the making of these pictures, because the camera doesn't have a viewfinder, only the LCD display (I mutter about that a lot), so the only risk is to the camera's sensor. The chief difficulty with this technique is that I couldn't see what I was doing 90% of the time. The glare on the screen was brighter than the filtered image of the sun (as you can gather by the reflection there). It was only when the sun began to set that the angle was such that I could actually see what was going on. Of course, most of the time nothing was going on, due to clouds.

Here's the photo I took down at the beach:

Transit of Venus, June 5, 2012

Venus, a pimple on the face of the sun! We also see our friends the sunspots from yesterday. (Click for bigger images.)

After a while I figured I'd done enough there, and it was time to come home. It takes me about 40 minutes to drive home, and it was hot and sunny the entire way. It was sunny when I got home. It was, however, cloudy by the time (about five minutes later!) I got the tripod set up again. The clouds didn't clear off again until the transit was nearly over:

This way to the egress!
Transit of Venus during egress, June 5, 2012

The sun looks a bit mottled and bilious because this was shot through thin fog. Yes, Venus is the little notch in the sun's lower right. I had hoped to be able to show you several phases of the transit, but c'est l'astronomie. I was lucky to be able to see it at all.

And, as the sun sinks slowly in the west, that concludes our broadcast day.

Sunset, June 5, 2012


Monday, June 04, 2012

Moon Missing, Sun Spotted

So last night I was puttering around before bed, when something caught my eye through the skylight. Oh! It's just the half moon. Well, that's all...wait...the moon is full. What's it doing half? Must be an eclipse. And, indeed it was. Funny, I hadn't heard about it. Must've been concentrating too hard on the transit of Venus tomorrow. Anyway I rushed out to see if I could get a pic. I had to prop the camera up against the porch railing, and hold it carefully in place, anchoring my left arm around a convenient spiderweb, but it turned out pretty well, considering:

Partial lunar eclipse, June 4, 2012

Turns out it's very scary outside at night. There were evil little rustlings, punctuated by tiny thuds, as if small yet vicious rodents were sneaking up on you. And then there were simply ghastly gnawing sounds, like the small vicious rodents nibbling the bones of previous unwary night photographers. But the former turned out to be the dropping of failed baby avocados, and the latter were the palm fronds rubbing one another.

There was also the occasional hideous shriek, but those didn't bother me; that was just the deer.

During the day today wasn't nearly as scary. As practice for tomorrow's festivities, I tried taking a picture of the sun through a solar viewer (that is, a piece of specially-made dark film, mounted in cardboard, that I very professionally held in front of the lens). But at least I used the tripod. I don't think it turned out badly:

The Sun! June 4, 2012

(I have just realized that the image names here say 20120603, but it was really 20120604)

You can see sunspots! Barely. Here's a quick-n-dirty enhancement using an unsharp mask. Sunspots are labeled. Click for a larger image.

Image above with unsharp mask applied, with sunspot groups labeled.

Yeah, yeah, I know -- kind of looks like a crayon drawing. But it's real!

Compare with this image from the Solar Dynamics Observatory's Helioseismic and Magnetic Imager:

SDO/HMI Intensitygram

That image came from here. I rotated it 90 degrees, scaled it down, and added the sunspot labels. Found those at, but there wasn't a permanent link. Any errors are mine.

So, really, that's pretty good for a cheap $200 camera. The gazillion-dollar solar satellite makes much prettier pictures, though.

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