Brown astronomers prepare for eclipse and College Hill viewing event

Brown will host a public viewing event for the Aug. 21 eclipse, as several of the University’s astronomers head to prime viewing locations of the total eclipse out west.

PROVIDENCE, R.I. [Brown University] — Unless you’ve been living directly behind a giant rock this summer, you’re probably aware that a solar eclipse will be visible over much of the continental U.S. on Monday, Aug. 21. As several of Brown’s astronomers gear up for trips to prime viewing locations out west, a group of students and staff will offer members of the public a chance to safely view the event on the University’s main green.

A large swath of the country stretching from Oregon to Georgia will have a chance to see a total eclipse, while much of the rest of the country will see a partial eclipse. In Providence, the Moon will obscure about 70 percent of the sun’s face.

“Partial eclipses are interesting to view if the proper precautions are taken to protect one’s eyes,” said David Targan, associate dean of the College for science education and director of Brown’s Ladd Observatory. “As the Moon’s disc gradually covers and uncovers the sun, the sky itself will only get slightly darker — so most people will not notice the eclipse unless they are looking at it, which they should only do through eclipse glasses or a filtered telescope.”

Brown astronomy students, under the direction of Targan and physics professor Ian Dell’Antionio, will provide both of those on the main green.

“We’ll have six different telescopes and a couple hundred eclipse glasses,” Dell’Antonio said. “It’s important to stress that this is a slow-moving event and people don’t need to be here at any one particular time.”

The Moon’s traverse across the face of the sun will begin around 1:30 p.m. and end around 4 p.m. The moment of maximum obscuration will be around 2:45 p.m. The viewing event is free and open to the public, assuming acceptably clear skies.

For those who can’t make it to the green, staff members from the Ladd will be broadcasting live pictures from the rooftop of Brown’s Barus and Holley building on the web:

But perhaps the most interesting way to view the partial eclipse, Dell’Antonio says, is to find the shadow of a leafy tree and look down rather than up. The small gaps between tree leaves effectively create thousands of pinhole cameras, which will project images of the eclipsed sun onto the ground.

“The little light dapples on the ground will be crescent suns,” Dell’Antonio said. “It’s amazing — the best thing about a partial eclipse, I think.”

A history of eclipse research

When Brown’s Ladd Observatory opened in 1891, eclipse science was a big deal. Before satellites, eclipses were the only chance to study the corona — the sun’s outer atmosphere — which is usually rendered invisible by the bright glare from the surface. And there were other discoveries to be had. During an eclipse in 1919, for example, scientists were able to observe how starlight curved around the darkened sun, which provided evidence that Einstein’s theory of relativity was correct.


The Ladd’s founding director, Winslow Upton, was a well-known eclipse scientist, who traveled on at least six expeditions to view eclipses in various parts of the world between 1878 and 1905. After Upton, Charles Smiley, who directed the Ladd from 1931 to 1970, would eclipse even Upton as an expert on eclipses.


“Smiley was the eclipse astronomer of his day,” Targan said.

He designed special telescopes to take pictures of eclipses (one of which is on display at the Ladd), and for a time was recognized as having possibly spent more time under totality (the moments during a total eclipse when Moon blocks the sun’s entire visible surface) than anyone on Earth, Targan says. He led more than a dozen eclipse expeditions to remote locations all over the world, and even flew in an Air Force fighter jet along the path of an eclipse shadow at Mach 2 to increase his time under totality.

It was Smiley and an eclipse excursion that would eventually bring Targan, who has directed the Ladd since 1989, to Brown. In the late 1960s, Targan, a budding astronomer at the time, signed up to help on a cruise ship headed out to view an eclipse over the Atlantic Ocean.

“A lot of the people on the ship had just bought their telescopes to go on this and had no idea how to use them,” Targan said. “So it was my job to help people get set up.”

Smiley ended up being one of the people on that ship (along with the great science fiction writer and professor Isaac Asimov). “That’s where Smiley recruited me to come to Brown,” Targan said. “And here I am.”

Targan and Dell’Antonio themselves won’t be on campus for the event. They’re both heading to locations out west that are in the path of totality and where cloudy skies are unlikely this time of year.

“Part of what makes this eclipse such a big deal is that millions of Americans will have the opportunity to fly or drive to the path of totality, since it sweeps right across the continental United States,” Targan said.

Targan has seen two prior total eclipses and says there’s nothing quite like it.

“The sun looks like it's been turned off and the sky gets very dark,” Targan said. “What's more, the black disc is surrounded by a red ring that includes bright red prominences close to the sun, and farther out, the glowing plasma of the sun's superheated corona. Looking away from the eclipsed sun, it will be possible to see the planets Mercury, Venus and Mars in the middle of the day. All of these incredible sights make total eclipses among the most spectacular events visible in the natural world.”

And while people staying back on College Hill won’t get to see a total eclipse this time around, it won’t be too long until one comes close by. In 2024, there will be a total eclipse over parts of northern New England.

“So if you miss this one, be thinking about 2024,” Dell’Antonio said.