Monday May 3, 2021’s Smile of the Day: Baily’s Beads

On this Day:

In 1715, Edmond Halley observed the total eclipse phenomenon “Baily’s Beads”.

The Baily’s beads effect or diamond ring effect is a feature of total and annular solar eclipses. As the Moon covers the Sun during a solar eclipse, the rugged topography of the lunar limb allows beads of sunlight to shine through in some places while not in others. The effect is named after Francis Baily, who explained the phenomenon in 1836. The diamond ring effect is seen when only one bead is left, appearing as a shining “diamond” set in a bright ring around the lunar silhouette.

Lunar topography has considerable relief because of the presence of mountains, craters, valleys, and other topographical features. The irregularities of the lunar limb profile (the “edge” of the Moon, as seen from a distance) are known accurately from observations of grazing occultations of stars. Astronomers thus have a fairly good idea which mountains and valleys will cause the beads to appear in advance of the eclipse. While Baily’s beads are seen briefly for a few seconds at the center of the eclipse path, their duration is maximized near the edges of the path of the umbra, lasting 1–2 minutes.

After the diamond ring effect has diminished, the subsequent Baily’s beads effect and totality phase are safe to view without the solar filters used during the partial phases. By then, less than 0.001% of the Sun’s photosphere is visible.

Observers in the path of totality of a solar eclipse see first a gradual covering of the Sun by the lunar silhouette for just a small duration of time from around one minute to four minutes, followed by the diamond ring effect (visible without filters) as the last bit of photosphere disappears. As the burst of light from the ring fades, Baily’s beads appear as the last bits of the bright photosphere shine through valleys aligned at the edge of the Moon. As the Baily’s beads disappear behind the advancing lunar edge (the beads also reappear at the end of totality), a thin reddish edge called the chromosphere (the Greek chrōma meaning “color”) appears. Though the reddish hydrogen radiation is most visible to the unaided eye, the chromosphere also emits thousands of additional spectral lines.

Although Bailey is often said to have discovered the cause of the feature which bears his name, Sir Edmond Halley made the first recorded observations of Baily’s beads during the solar eclipse of 3 May 1715. Halley described and correctly ascertained the cause of the effect in his “Observations of the late Total Eclipse of the Sun[…]” in the Philosophical Transactions of the Royal Society:

About two Minutes before the Total Immersion, the remaining part of the Sun was reduced to a very fine Horn, whose Extremities seemed to lose their Acuteness, and to become round like Stars … which Appearance could proceed from no other Cause but the Inequalities of the Moon’s Surface, there being some elevated parts thereof near the Moon’s South Pole, by whose Interposition part of that exceedingly fine Filament of Light was intercepted.

Cosmas Damian Asam was probably the earliest realistic painter to depict a total solar eclipse and diamond ring. His painting was finished in 1735.

The Baily’s beads phenomenon is seen during the credit opening sequence of the NBC TV show Heroes, while the Diamond Ring effect is seen during the credit opening sequence of Star Trek: Voyager, albeit from a fictitious extrasolar body, seen from space (per Wikipedia).

First, a Story:

What do you see when you hold a bottle of Mexican beer up towards the sun during a solar eclipse?

Corona.

Second, a Song:

“Total Eclipse of the Heart” is a song recorded by Welsh singer Bonnie Tyler. It was written and produced by Jim Steinman, and released on Tyler’s fifth studio album, Faster Than the Speed of Night (1983). The song was released as a single by Columbia Records in 1983.

The song became Tyler’s biggest career hit, topping the UK Singles Chart, and becoming the fifth-best-selling single in 1983 in the United Kingdom. In the United States, the single spent four weeks at the top of the charts, keeping another Steinman penned song “Making Love Out of Nothing at All” by Air Supply from reaching the top spot (a song Tyler would later cover in 1995), and it was Billboard’s number-six song of the year for 1983. The song was nominated for the Grammy Award for Best Female Pop Vocal Performance.

Worldwide, the single has sales in excess of 6 million copies and was certified Gold by the Recording Industry Association of America (RIAA) for sales of over 1 million copies after its release, updated to Platinum in 2001 when the certification threshold changed. In 2015, the song was voted by the British public as the nation’s third favourite 1980s number one in a poll for ITV (per Wikipedia).

Korean television series or Korean drama, more popularly known as K-dramas, are television series in the Korean language, made in South Korea. Korean dramas are popular worldwide, partially due to the spread of Korean popular culture (the “Korean Wave”), and their widespread availability via streaming services which often offer subtitles in multiple languages. Many K-dramas have been adapted throughout the world, and some have had great impact on other countries. Some of the most famous dramas have been broadcast via traditional television channels in other countries. For example, Dae Jang Geum (2003) was sold to 91 countries.

GMA Network was founded by Robert La Rue Stewart in 1950 as Republic Broadcasting System (RBS) with flagship AM radio station DZBB. RBS ventured into television in 1961 and began broadcasting on Channel 7 in the Greater Manila Area, Philippines.

In 1974, the triumvirate of Felipe L. Gozon, Menardo R. Jimenez and Gilberto M. Duavit took over the management of RBS. In 1996, RBS was renamed GMA Network, Inc.

Today, GMA Network, Inc. is the leading broadcasting company in the Philippines which produces the most innovative, most trusted, and top rating TV programs. It operates a network of 47 VHF and 41 UHF TV stations, as well as 24 radio stations throughout the country (per https://www.gmanetwork.com/corporate/).

Here is “Total Eclipse of the Heart”, the local theme song of GMA-7’s Scarlet Heart (Moon Lovers: Scarlet Heart Ryeo), a K-drama about a girl and her two lovers, performed by Hazel Faith under Curve Entertainment (per YouTube.com). I hope you enjoy this!

(https://www.youtube.com/watch?v=_VKA_akb3RI)

Thought for the Day:

“Turn your face to the sun and the shadows fall behind you.” – Unknown

Cheers!

Have a great day!

Dave & Colleen

© 2021 David J. Bilinsky and Colleen E. Bilinsky

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