CLAUDIA HARMON WORTHEN and WOODY SCHLAM
Beautify Cambria Association (BCA) is hosting its 9th Annual Bee, Butterfly & Bat Faire on Sunday, May 4, at the Cambria Historical Museum, at the corner of Burton & Center Street, from 11 a.m. to 3 p.m.
Beautify Cambria offers solar telescopes for public viewing at the Faire. Why? Sunlight—photosynthesis—is essential for growing flowers for our pollinators and provides the energy source for nearly all living organisms.
Woody Schlam, of the Central Coast Astronomical Society and San Diego Astronomy Association, shared the exciting news about solar observation this year with Beautify Cambria.
“This is a great time to observe our nearest star, the sun, because it’s more active now than it will be for another eleven years. What does “more active” mean? It means more sunspots, more prominences, more solar flares, and more Aurora Borealis (Northern Lights).
This most active solar period is called “Solar Max,” and it happens every 11 years. We’re on solar cycle number 25 right now, which should peak in July. Then solar activity will diminish over the next five and half years until we reach “Solar Minimum” sometime in 2031 and the cycle begins again. (The sun also undergoes a pole shift as its north and south poles switch places].
During Solar Max we see the most sunspots and other solar details. We’re often seeing a dozen or more sunspots a day now during Solar Max. And five and a half years from now at Solar Minimum we probably won’t see a single sunspot for months. The same goes for other solar features such as prominences and flares – there are virtually none at Solar Minimum. So again, this is a great time to observe our sun through properly filtered telescopes and binoculars.
But wait – isn’t it dangerous to look directly at the sun? Well yes. Not only is the sun blindingly bright, but it also contains very harmful UV (Ultraviolet) rays that can permanently damage the eye.
To make solar observing safe, we need to filter out most of the brightness, but even more importantly, ALL the harmful rays. The filters on our telescopes and binoculars filter out 99.9% of all light wavelengths and 100% of UV. And the same goes for the special solar glasses that are available to safely look directly at the sun. Some of us solar observers still have a supply of the special solar glasses we bought for the last solar eclipse and plan make them available to visitors [at the Bee, Butterfly & Bat Faire].
With the special solar glasses and the most common solar filters used on telescopes and binoculars, we can clearly see sunspots. But that’s about all. These “simple” solar filters display the sun’s photosphere layer and are called white-light filters. But they don’t reveal solar details such as prominences, filaments, plage (super-hot and active areas), magnetic fields, or solar flares which occur on the sun’s next outer layer, the chromosphere. To see those details, you need much more specialized (and expensive) filters.
The most common specialized solar filter is called a “Ha” or Hydrogen-alpha filter. With a proper Ha filter on a telescope or binoculars, we can see details such as prominences (fountains of super-heated and pressurized gas and plasma) erupting from the sun’s outer limb. Solar flares are similar, just much, much stronger and larger – and more rare. Ha filters also allow us to see other surface details such as filaments, plage, and often some magnetic fields.
Another specialized solar filter amateur solar observers are beginning to use is the CaK filter (Calcium K). This filter blocks all light except a narrow wavelength of deep blue light and displays the transition area between the sun’s photosphere and chromosphere.
We plan to have a combination of all these solar observing scopes at the Faire to share with attendees. And in addition to regular telescopes with eyepieces, we’ll have at least one Ha live video system where the solar images are clearly displayed on monitors so everybody (including small children and the handicapped) can see and discuss the sun.“
Beautify Cambria is honored to have Woody share his knowledge and solar viewing equipment at this year’s Faire. There will be three additional amateur astronomers sharing their solar telescopes, including the newest smart telescope, the Sunstar S50. Read more about stargazing and the Bee, Butterfly & Bat Faire at: beautifycambria.org.
Photo credit top: NASA, massive solar prominence
Hydrogen-alpha filter —white-light filter—Calcium K filter
Partial solar eclipse using Camera Assisted Observing (CAO)
Photo courtesy of Woody Schlam
