October’s Partial Solar Eclipse

On October 23, 2014, a partial eclipse of the Sun was widely visible from North America (see: Partial Solar Eclipse of 2014 Oct 23). I observed the eclipse from Sacramento Peak, New Mexico while attending the 2014 Solar Eclipse Conference (see: 2014 Solar Eclipse Conference).

I wasn’t particularly excited about this event because I’ve seen many total solar eclipses (see: MrEclipse.com), but about one week before the eclipse, an enormous sunspot complex rotated into view. Designated AR2192, this active region was about the size of Jupiter making it the largest sunspot in 24 years (see: APOD: Giant Sunspot).

The AR2192 Sunspot group rotated into view from behind the Sun about a week before the partial solar eclipse. It was visible to the naked eye using a solar filter. ©2014 by Fred Espenak.

The AR2192 Sunspot group rotated into view from behind the Sun about a week before the partial solar eclipse. It was visible to the naked eye using a solar filter. ©2014 by Fred Espenak.

Suddenly, my interest was piqued because the sunspot would be well placed during the eclipse. I packed up my Vixen 90mm f/9 fluorite refractor and a Losmandy GM-8 equatorial for the trip to New Mexico. I usually test all my equipment days or weeks before an eclipse, but this was a busy time with several house guests and two talks to prepare before the eclipse conference, so no system testing was done.

Fred Espenak observes the partial solar eclipse from Sacramento Peak, NM. ©2014 by Pat Espenak.

Fred Espenak observes the partial solar eclipse from Sacramento Peak, NM. ©2014 by Pat Espenak.

I soon discovered two equipment problems as the eclipse began. Although my rechargeable battery was freshly charged, it died early into the eclipse. I then switched to my car battery. A second problem presented itself when the telescope failed to track the Sun. The fast/slow buttons of the drive worked to position the Sun, but it would slowly drift out of the field. My only recourse was to use the fast/slow buttons to recenter the Sun before each exposure.

Because I planned to shoot a time-lapse video of the eclipse I needed to make exposures quite frequently – in this case, every 30 seconds. Consequently, I had to remain near the telescope for the full 2.25 hours of the eclipse to center the Sun before every exposure. This was turning into much more work than I had anticipated, but the clear weather, good seeing and that wonderful sunspot kept me at my post until the eclipse ended.

At maximum eclipse, about 43% of the Sun's diameter was covered by the Moon. ©2014 by Fred Espenak.

At maximum eclipse, about 43% of the Sun’s diameter was covered by the Moon. ©2014 by Fred Espenak.

A month passed before I found the time to begin processing the 270 separate eclipse images in Adobe Photoshop. The first step was to create a circular reference template to manually center each photo. This took about 9 hours. I then created a Photoshop action to crop and resize the frames and to make adjustments to the histogram. Finally, the frames were assembled into a 10-frame-per-second time lapse video using Time Lapse Assembler on an 11″ Macbook Air and uploaded to Vimeo.

The resulting video shows the Moon gracefully swinging across the northern half of the Sun while sunspot AR2192 remains in full view.


Partial Solar Eclipse of 2014 Oct 23 from Fred Espenak on Vimeo.

And now, it’s time to begin preparing for the total solar eclipse of March 20, 2015 in the Faroe Islands (see: Total Solar Eclipse of 2015 Mar 20). Hopefully, I’ll do a better job of testing my gear before that eclipse!

Fred Espenak


Enormous Sunspot in 2014

In the first days of 2014, an enormous sunspot appeared along the eastern edge of the Sun. Formally known as Active Region 1944 (or AR1944), this feature is actually composed over 60 individual sunspots. The largest of them is several times larger than planet Earth.

The Sun and Active Region 1944 as seen on 2014 Jan 07. For more information, see Sun and Sunspot.

The Sun and Active Region 1944 as seen on 2014 Jan 07. For more information, see Sun and Sunspot. Photo ©2014 by Fred Espenak

So large is AR 1944, that it can be seen with the naked eye provided you use a solar filter to attenuate the Sun’s intense light. I’ve spotted AR 1944 with nothing more that a pair of eclipse glasses left over from a past eclipse trip. Last night (Jan. 06), I photographed the Sun setting behind some of the rugged peaks of the Chiricahua Mountains near my home in Portal, AZ. I found it fascinating to watch the Sun and AR 1944 pass behind the distant spires before disappearing from view.

AR1944 is easily seen as the Sun sets among the rugged peaks of the Chiricahua Mountains on January 06. For more information, see Sunset with Sunspot. Photo ©2014 by Fred Espenak

AR 1944 is easily seen as the Sun sets among the rugged peaks of the Chiricahua Mountains on January 06. For more information, see Sunset with Sunspot. Photo ©2014 by Fred Espenak

In spite of being an active region on the Sun, AR 1944 has been relatively quite since its appearance. But that could change quickly with a powerful solar flare. According to SpaceWeather.com: “The sunspot has an unstable ‘beta-gamma-delta’ magnetic field that could erupt at any time. NOAA forecasters estimate a 75% chance of M-class flares and a 30% chance of X-flares on Jan. 7th.”

Since AR 1944 is now appears near the center of the Sun’s disk, it is aimed directly at Earth. So any major eruptions will spew high energy particles and x-rays directly at us, possibly triggering a major geomagnetic storm. Such events can damage satellites in high geosynchronous orbits. This is where most communications satellites orbit, so a major flare can effect global telecommunications. For more on this topic, see What impact do solar flares have on human activities?.

A closeup of AR1944 reveals that the large sunspot is actually composed of dozens of smaller sunspots. This image was made on January 7 from Portal, AZ . For more information, see Sunset with Sunspot. Photo ©2014 by Fred Espenak

A closeup of AR 1944 reveals that the large sunspot is actually composed of dozens of smaller sunspots. This image was made on January 7 from Portal, AZ . For more information, see Sunset with Sunspot. Photo ©2014 by Fred Espenak

Solar physicists and space weather experts will be watching AR 1944 closely in the coming days. And so will amateur astronomers and sky watchers around the globe.

Fred Espenak

Update: According to NASA: “The sun emitted a significant solar flare, an X1.2, peaking at 3:31 p.m. EST on Jan.7, 2014. This is the first significant flare of 2014, and it follows on the heels of mid-level flare earlier in the day.” The source of this flare is AR 1944.