PROVIDENCE, R.I. [Brown University] — A Providence landmark — and a window to the stars for generations of Brown astronomers, students and Rhode Island skywatchers — will celebrate its 125th anniversary the week of Oct. 17.
The Ladd Observatory, located just north of the University’s campus on Doyle Avenue in Providence, opened its doors for the first time on October 21, 1891. Ever since, the Ladd has been open for weekly public viewing nights, providing an astonishing view of the Moon, neighboring planets, comets, meteors and distant stars. The Ladd staff will commemorate the anniversary with a series of talks by scientists and astronomers starting on Monday Oct. 17, a birthday cake celebration on Friday, Oct. 21 and two nights of public sky viewing on Tuesday and Friday.
The schedule of anniversary events can be found here.
“The Ladd is considered a gem by the national astronomical community,” said David Targan, associate dean of the college for science education and the Ladd’s director. “It’s one of the best examples in the country of a continuously operating, finely preserved 19th century observatory. For Brown, it’s been an important means of connecting with the community and communicating science, as well as simply giving people a beautiful view of the night sky.”
Construction of the Ladd began in May 1890, overseen by renowned astronomer Winslow Upton, who would serve as the facility’s first director. Upton was lured to Brown as a professor in 1883 with a promise that the University would build a state-of-the-art observatory. Thanks to a $55,000 gift from former Rhode Island Gov. Herbert Warren Ladd, the University was able to make the observatory a reality.
The facility’s main attraction is its colossal refracting telescope. Measuring 15 feet long, with a 1-foot-diameter lens, it’s an ideal instrument for viewing intricate surface features on planetary bodies, Targan says. The telescope is powerful enough to see the detailed patterns of Saturn’s rings and resolve the borders of Jupiter’s atmospheric bands. When viewing the Moon, it brings the rims of craters, the rays of impact ejecta and other features into sharp focus.
The telescope was on the cutting edge when it was built, but it was also among the last of its kind built in the eastern U.S., Targan says.
“Industrialization had started creating more light pollution in the east, so around this time astronomers and telescopes started migrating out west to work in places that were darker, higher in elevation and had clear, dry air,” Targan said. “This was really the end of an era for these big telescopes on the East Coast.”
Initially, the plan was to build the observatory in the middle of the College Green. But that plan was scrapped in favor of a location that was (at the time) more rural, away from buildings and city lights. In the 125 years since the Ladd’s construction, a busy urban neighborhood has grown up around it. But that growth, and the ambient light that comes with it, hasn’t changed the viewing experience much, Targan says.
“What’s affected by light pollution are views of faint objects like distant galaxies, which aren't really the strength of a refracting telescope anyway,” he said. “Everything else — the details of planets and the Moon, which is what the refractor is best for — is really the same as it ever was.”