2020_Solar_Week.html

Welcome to SOLAR WEEK, 2020

With the Covid-19 virus all around us we are being advised to practice Social Distancing. Here are some solar activities to learn about our very own Star & the Sun-Earth connection.
Over the next five days I will be posting daily activities that can be carried out at home and enjoyed dy individuals and/or small family groups.

Mar 23-27, 2020

Monday - The Sun As a Star
Tuesday - Solar Close-Ups
Wednesday- The Active Sun
Thursday - The Sky Above: Earth's Upper Atmosphere
Friday - Solar Careers, Internships and Opportunities

Solar Week, a week of online lessons, games and hands-on activities about the Sun for grades 5-9 or ages 9-14

Tuesday, March 24th, 2020 - DAY 2

ACTIVITY 1- How do amateur astronomers observe and take pictures of the sun?

Safety is the first and foremost consideration when attempting to view the sun. Mistakes can be costly and dangerous, resulting in acute harm, blindness and/or death. Serious injury can also result to equipment id strict safety guidelines are not followed. Please do not EVER attempt to do solar viewing of any kind without proper adult superviosin. Even SAFETY SOLAR GLASSES can be


Solar Projection is one easy way to get started viewing the sun as demonstrated by Dorothy O'Neal. Here's a link to build a Sun Funnel to view the sun with your telescope.	Another easy way to get started viewing the sun is with an APPROVED pair of SAFETY SOLAR GLASSES as demonstrated by Pamela Shivak. BUY HERE!	Some telescopes have special narrowband filters DON'T ever use a telescope to view the sun w/out adult supervision. The images below used these specialized narrowband filters

Hydrogen Alpha view of the Sun	Sodium D view of the Sun	Calcium H view of the Sun
The above 3 images were shot with DAYSTAR Filters QUARK Solar Filters.

ACTIVITY II- Who is Joseph von Franhofer and why is he important to solar astronomy? CHECK OUT THIS ARTICLE AND THESE LINKS TO FIND OUT:

Joseph Ritter von Fraunhofer was a Bavarian physicist and optical lens manufacturer. He made optical glass and achromatic telescope objective lenses, invented the spectroscope, and developed diffraction grating. In 1814, he discovered and studied the dark absorption lines in the spectrum of the sun now known as Fraunhofer lines. The German research organization Fraunhofer Society is named after him and is Europe's biggest Society for the Advancement of Applied Research.

One of the most difficult operations of practical optics during the time period of Fraunhofer's life was accurately polishing the spherical surfaces of large object glasses. Fraunhofer invented the machine which rendered the surface more accurately than conventional grinding. He also invented other grinding and polishing machines and introduced many improvements into the manufacture of the different kinds of glass used for optical instruments, which he always found to have flaws and irregularities of various sorts. In 1811, he constructed a new kind of furnace, and during his second melting session when he melted a large quantity of glass, he found that he could produce flint glass, which, when taken from the bottom of a vessel containing roughly 224 pounds of glass, had the same refractive power as glass taken from the surface.

He found that English crown glass and German table glass both contained defects which tended to cause irregular refraction. In the thicker and larger glasses, there would be even more of such defects, so that in larger telescopes this kind of glass would not be fit for objective lenses. Fraunhofer accordingly made his own crown glass. It was thought that the accurate determination of power for a given medium to refract rays of light and separate the different colors which they contain was impeded by the absence of precise boundaries between the colors of the spectrum, making it difficult to accurately measure the angle of refraction. To address this limitation, Fraunhofer performed a series of experiments for the purpose of producing homogeneous light artificially, and unable to effect his object in a direct way, he did so by means of lamps and prisms.

By 1814, Fraunhofer had invented the modern spectroscope. In the course of his experiments, he discovered a bright fixed line which appears in the orange color of the spectrum when it is produced by the light of fire. This line enabled him afterward to determine the absolute power of refraction in different substances. Experiments to ascertain whether the solar spectrum contained the same bright line in orange as the line produced by the orange of fire light led him to the discovery of 574 dark fixed lines in the solar spectrum. Today, millions of such fixed absorption lines are now known.

Continuing to investigate, Fraunhofer detected dark lines also appearing in the spectra of several bright stars, but in slightly different arrangements. He ruled out the possibility that the lines were produced as the light passes through the Earth’s atmosphere. If that were the case they would not appear in different arrangements. He concluded that the lines originate in the nature of the stars and sun and carry information about the source of light, regardless of how far away that source is. He found that the spectra of Sirius and other first-magnitude stars differed from the sun and from each other, thus founding stellar spectroscopy. These dark fixed lines were later shown to be atomic absorption lines, as explained by Kirchhoff and Bunsen in 1859. These lines are still called Fraunhofer lines in his honor; his discovery had gone far beyond the half-dozen apparent divisions in the solar spectrum that had previously been noted by Wollaston in 1802.

Fraunhofer also developed a diffraction grating in 1821, after James Gregory discovered the principles of diffraction grating and after the American astronomer David Rittenhouse invented the first manmade diffraction grating in 1785. Ultimately, however, his primary passion was still practical optics; he once wrote that "In all my experiments I could, owing to lack of time, pay attention to only those matters which appeared to have a bearing upon practical optics"

Fraunhofer produced various optical instruments for his firm. This included the Fraunhofer Dorpat Refractor used by Struve (delivered 1824 to Dorpat Observatory), and the Bessel Heliometer (delivered posthumously), which were both used to collect data for stellar parallax. The firm's successor, Merz und Mahler, made a telescope for the New Berlin Observatory, which confirmed the existence of the major planet Neptune. Possibly the last telescope objective made by Fraunhofer was supplied for a transit telescope at the City Observatory, Edinburgh, the telescope itself being completed by Repsold of Hamburg after Fraunhofer's death.

I have some old videos that were posted online at some point in time and I downloaded them to my hard drive for study. I uploaded the videos to my YOUTUBE Channel so I could share them with others. Here are the links to the videos:

Joseph von Franhofer Instructional Video - 13 minutes duration.

Joseph von Franhofer - Diffraction of Light - 15 minutes duration

Joseph von Franhofer - Refraction, Dispersion & Diffraction of Light - 34 minutes duration

ACTIVITY III - Daily Solar Activities, Games, etc.

Check out the solar week daily activities located on the SOLAR WEEK Website:
http://multiverse.ssl.berkeley.edu/Solar-Week/Tuesday

ACTIVITY IV - Video of the Day

Check out my GREAT AMERICAN TOTAL SOLAR ECLIPE OF AUGUST 21ST, 2017, shot at Smith's Ferry, Idaho. The video can be found on my ncstargazer.com website and/or on my John O'Neal NC Stargazer YOUTUBE Channel:

https://www.youtube.com/watch?v=hRsEBqtYkM0