Fall marked with Pen Henge party

Public invited to mark the fall equinox at the Pen Henge standing stone array at the top of Munson Mountain near Penticton.

Members of the public are invited to mark the fall equinox at the Pen Henge standing stone array at the top of Munson Mountain near Penticton.

The Okanagan Centre of the Royal Astronomical Society of Canada (OCRASC) will host the event on Sept. 22 to watch the sun set along the line extending from the heel stone to the equinox stone of the array.

People will gather for the Pen Henge observance around 5:45 p.m. in preparation for the sunset performance at 6:20 p.m. OCRASC members will be on hand to answer questions about the equinox as well as the history of the Pen Henge array and how it operates. The array is located at the top of Munson Mountain directly above the Penticton sign, and it is reached by a pathway leading up from the parking lot in the park.

In addition to interpreting the equinox and the array for visitors, OCRASC members will also have specially filtered telescopes on hand to show sunspots and other features on the Sun’s disk. As always, it is dangerous to look directly at the Sun without proper eye protection.

Pen Henge was conceived in 2009 during the International Year of Astronomy (IYA) by members of the Okanagan Astronomical Society in Penticton which has since become part of OCRASC. The project was spearheaded by Chris Purton and assisted by OCRASC members plus the active support of Penticton city council and parks supervisor Jeff Lynka.

The standing stone array is made up of four stones; a heel stone to the east, and three other stones which mark the sunset direction at the Winter Solstice in December, the spring and fall equinoxes in March and September, and the Summer Solstice in June. At those times the Sun’s shadow extends from the respective marker stone directly to the heel stone.

Photos of the array and some of the earlier solstice and equinox observances can be found on the OCRASC image gallery at rascoc.zenfolio.com/p500357414.

The Okanagan Centre of the Royal Astronomical Society of Canada has over 100 members extending from Osoyoos to Salmon Arm. Interested members of the public are welcome to attend regular OCRASC meetings which will take place in Kelowna, Penticton and Vernon on Sept. 22, 24 and 30 respectively. Meeting details can be found on the club’s website www ocrasc ca.

The organization also operates the Okanagan Observatory which is located on the Big White Road west of Kelowna.

Free public viewing as well as a free audio visual presentation are offered on clear Friday evenings at the observatory. The public evenings can be confirmed by calling 250-300-8759 after 3 p.m. every Friday afternoon. Actual observing is offered through member telescopes as well as the Observatory’s own 25 foot reflecting telescope.