David Cortner's Slowblog

11/14/2012. The difference a week makes. The sunspot number has tripled; there are multiple spots and some are complex. 1613 has thrown a series of M-class flares and C-class "flickers." It's not the most picturesque complex on the Sun, though. Here's 1614, a sprawling tangle of magnetic lines:

1613bw

1613col

I collected several GB of data in the cul de sac; this is just the most spectacular group. Seeing was awful, so I took long clips which I concatenated in VirtualDub before asking AVIStack 2 to pick the best 125 frames. The b/w image above comes from 2,400 frames; the color from 1,700. High, thin clouds made prominence photography challenging:

proms

The same high clouds that made solar photography tough today made this photograph possible:

arc

That's the most vivid circumzenithal arc I've ever seen. Right click and "view image" to see it at higher resolution. (Canon 5D, 24-105 F4L @ 95mm)

11/16/2012. Another day, another 50GB. The black and white image is a six-frame mosaic of sprawling active regions 1614 and 1615. The color shot is a look at (hyper) active region 1613. I was observing from the cul de sac using the 90mm solar outfit powered from the Honda's auxillary power outlet (a cigaette lighter plug by any other name), and, as usual, the best 150 frames from each 1GB clip were used to produce these web-sized distillations:

1614

1613

Right click and "View Image" for larger images

Today's skies offered excellent seeing with just enough high haze to light up a sun dog to the west of the Sun from time to time. The good conditions let me use 1GB clips to good advantage, though I couldn't resist a few massive files to see what could be done with them. The color photo there comes from a 2,400 frame clip; I'm sure finer detail can be teased out of it. Seeing was quite slow and of small amplitude. You can see stuff when the pond is this still.

11/17/2012. You'd know some physics if this frame held no mysteries: here are the hot and "cold" (hot and hotter?) plasma rivers surrounding active region 11613 on the Sun. It's a 3-frame mosaic made from our cul de sac -- best 150 out of 900 frames times three, aligned, stacked, and sharpened to defeat atmospheric turbulence. The 21st Century is a GOOD time to be an amateur astronomer.

1613

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Except where noted, solar photos are made with a Point Grey Research Chameleon camera behind a Lunt Solar Systems 60mm THa solar telescope double-stacked wtih a 50mm front etalon for an achieved bandwidth of about 0.55 Angstroms. The telescope uses a B600 blocking filter and is mounted piggyback with an Astro-Tech 10-inch Ritchey-Chretien (carefully capped!) on an Astro-Physics Mach1GTO mount. An Acer Aspire One netbook running Point Grey's Flycap software provides camera control and capture services via USB 2.0. Images typically begin as 20 second AVI's captured at 15 fps. 300 frame clips are aligned and stacked using Registax 6 or AVIStack 2.0. The resulting files are processed via wavelet functions in Registax and / or the FocusMagic 3.0.2 deconvolution plug-in in Photoshop CS4. (PixInsight is rapidly supplanting some of those steps.) The imaging train usually includes an Orion "Shorty" 2x barlow screwed into the 1.25-inch prime-focus snout. Exposures are on the order of 4-8 ms with gain set to 10-12 db, or 12-18ms at 0 gain. The barlow is sometimes replaced by an Antares 0.5x telecompressor sandwiched between the 1.25-inch snout and the C-adapter on the PGR Chameleon; this produces a full-disk image (during most of the year) and allows exposures in the 1ms range with slightly less gain. A RoboFocus motor with a timing belt looped around the stock (or, sometimes, a Feathertouch) focus knob enables remote operation.