Back to top

The shortest day

The UMass Sunwheel teaches the community about the stars

On December 21, 2023, a group of about 40 astronomy enthusiasts met at the UMass Amherst Sunwheel, located southwest of the flagship campus near the McGuirk Alumni Stadium, for the annual winter solstice event. The air was crisp, and even though there wasn’t a cloud in the sky, the fading sun’s light did little to warm the group. Still, the excitement of viewing the celestial event kept attendees in their places as firmly as the stone pillars in the surrounding circle.

Gathering at the center of the Stonehenge-like monument, the crowd focused on Bingqing Sun, a doctoral candidate in astrology, who explained how structures like this sunwheel are used around the world to track the seasons—and have been for millennia.

As the crowd listened, the already low-hanging sun made its final descent below the horizon line. Onlookers were encouraged to stand on stones in the center of the wheel, and from there, were able to see our sun set exactly where a large stone marker indicated, just as it happens without fail every year.

The Sunwheel project, born out of the mind of the late Professor Judith S. Young, began almost three decades ago in October 1995. Young received permission for its construction from the university, and with some help from Astronomist and Professor Emeritus Stephen Schneider, began tracking the placements of the rising and setting of the sun during each solstice and equinox. In 1997, two-foot stone markers were installed, with eight- and 10-foot stones added in a larger circle in November 2000. Since then, additions have been made to include moonrise and set points, as well as the set points of stars Sirius and Aldebaran.

The astronomy department uses the Sunwheel as an outdoor classroom for the community, offering free events such as this one for every solstice and equinox, at both sunrise and sunset. “The initial inspiration for building it came from discovering that most people, including our students, no longer know how the sun moves in the sky,” explains Schneider. “This was common knowledge just 150 years ago before modern technologies gave us other ways of tracking time and seasons, and we stopped looking.”

This was common knowledge just 150 years ago before modern technologies gave us other ways of tracking time and seasons, and we stopped looking.

The next gathering (an equinox) is on March 19, 2024—a day when we will have the same amount of daylight and darkness—and all are welcome to join in and learn. “This may sound academic,” Schneider says, “but understanding these motions helps in designing buildings and gardens that take best advantage of sunlight and shade, making spaces more comfortable and more energy efficient. It’s also simply beautiful to pause and see the cycles of nature in action.”