OMSI Star Party

Summer Solstice Celebration

OMSI, Rose City Astronomers, and Oregon Parks and Recreation invite you to a free evening under the stars. OMSI Star Parties provide a great opportunity to meet other people who share their interest in astronomy, and to view the planets, moon, stars, and other celestial sights through telescopes and binoculars of all sizes. From beginners to experts, all ages are invited. The scheduled viewing will be held at Stub Stewart State Park. Park Rangers will provide guided night hikes during the star party.

We recommend visiting OMSI’s website on the day of the party for possible weather-related cancellations. Warm clothing and a flashlight with a red light are recommended. Personal telescopes and binoculars are welcome.

Parking is FREE for guests on Oregon State Park Day on June 7.  To reach L.L. “Stub” Stewart State Park, take US-26 west of Portland and turn right on OR-47. The park is located 23 miles west of Portland.

About the Solstice

Believe it or not, summer officially begins with the summer solstice on June 20.  The June solstice is the moment the Sun is directly above the Tropic of Cancer in the Northern Hemisphere. This is the northernmost latitude it reaches during the year. After the solstice, it begins moving south again.

As seen from Portland (45N) on June 20th, the noon sun will reach its highest point in the sky near 68 degrees from the southern horizon.  We will have nearly 15 hours and 41 minutes of daylight, with sunrise at 5:21 a.m. and sunset at 9:03 p.m.  From the June solstice to the September equinox, we will have nearly 93 days of summer.   Compared to just under 9 hours of daylight on the Winter Solstice, with the sun at its lowest point near 21 degrees.

Solstice comes from the Latin words sol, meaning Sun, and sistere, meaning to come to a stop or stand still. On the day of the June solstice, the Sun reaches its northernmost position, as seen from the Earth. At that moment, its zenith does not move north or south as during most other days of the year, but it stands still at the Tropic of Cancer. It then reverses its direction and starts moving south again.

The June solstice is the only day of the year when all locations inside the Arctic Circle experience a continuous period of daylight for 24 hours. Due to atmospheric refraction, however, the midnight sun is visible for a few days before and on the June solstice from areas as far as 60 miles south of the Arctic Circle. As one moves further north of the Arctic Circle, the number of days with the Midnight Sun increases.

You can learn more about the solstice and the night sky in Starry Nights Live! shown daily in OMSI’s Kendall Planetarium.