Bad Astronomy

Monster Sunspot Will Make Thursday’s Eclipse That Much Cooler

AR 2192
Yegads. Click to penumbranate, like that thing needs to get any bigger.

Photo by NASA Solar Dynamics Observatory (Little SDO)

Right now, a truly ginormous sunspot is turning its baleful eye toward Earth.

The spot, called Active Region 2192, is a bit hard to wrap your brain around: Its dark core is easily big enough to swallow the Earth whole without it even coming close to touching the sides, and the whole region is several times larger than that, easily more than 100,000 kilometers across. It’s the biggest sunspot we’ve seen this solar cycle (bigger than one I reported on in January that was also huge).

It’s feisty, too, having blown off a series of moderate M-class solar flares recently, and one that edged into X-class. We’re expecting more from it as well, so stay tuned to SpaceWeather.com, SpaceWeatherLive.com, and Realtime Flares on Twitter for up-to-the-moment news about any big eruptions. [Update (Oct. 22 at 15:00 UTC): Yup. AR 2192 blew off an X1.6 flare at 14:00 UTC today.]

When I saw pictures of it a couple of days ago, I knew it would be big enough to see without binoculars or a telescope. Using just my solar viewing glasses (which are rated safe to use to view the Sun; see here for more) I easily saw the sunspot with my own eyes as a black blemish near the Sun’s edge. Holy wow!

I decided to try my hand at getting a shot of it. Sacrificing a pair of solar glasses, I rigged up a small filter for my camera, went outside, and got this:

AR 2192

Photo by Phil Plait

Not bad! You can see AR 2192, as well as a few other spots (including the small one near the Sun’s edge that is visible in the SDO picture at the top of this post).

Clouds started rolling in, but far from being discouraged I figured that might actually make for a dramatic scene. I was right:

Spooky. 

Photo by Phil Plait

Nifty. And good practice; I want to make sure I’m ready for the partial solar eclipse tomorrow.

Speaking of which, let me repeat my call: If you get good and clever shots of the eclipse, please let me know! I want to post a gallery of a half-dozen or so. Make sure you tell me where you took them, what equipment you used, and whether they’re also online (so I can link to you).