Wednesday, August 16, 2023 at 7:30 PM EDT


Cosmic Collisions:
Close Encounters in the Gum Nebula

This lecture is live at the Martz-Kohl Observatory and available online via Zoom. You are encouraged to come to the observatory to meet Dr. Alexandra Yep and join in our always lively Q&A after her talk. Later, we offer tours and, if the weather cooperates, viewing opportunities through the big telescopes.

When stars pass very close to each other, they potentially kick up comets from each other’s Oort clouds and cause heavy bombardment events. A collision of stellar associations can serve as a laboratory of close stellar encounters. A stellar association is a very loose cluster of stars that share a common origin, but have become gravitationally unbound. Dr. Alexandra Yep examines the collision of two stellar associations in the Gum Nebula in the southern sky, using multiple simulations. Fifty pairs of stars in these two associations are projected to pass close to each other. To ascertain how frequently association collisions occur, a linear survey is conducted on a total of 6 stellar associations in the plane of the Galaxy. Dr. Yep concludes that an association in this region may experience an association collision every 20 million years (20 Myr), and stars within that association may on average experience a close stellar encounter every 84 Myr due to association collisions.

Dr. Alexandra Yep is a poet turned astronomer. After earning her BFA in creative writing and classical studies, she dove straight into quantum mechanics on her way to a Ph.D. in astronomy. Now a professor at Agnes Scott College in Atlanta, Georgia, she researches young stars and star clusters. As part of her work, she discovered several star clusters in the Gum Nebula which are now known as Yep-1, Yep-2 and Yep-3 and is only the second woman to have earned this type of naming honor.

Dr. Yep quips, “I like stars (the love is quite simplistic… they look pretty, and Tolkien liked them), and collisions and interactions are exciting.”

A non-member donation of $5.00 for adults and $2.00 for students is appreciated but not required for presentations and events.  You can donate at the observatory or on our donation page. Thanks!


Zoom Meeting

Time: August 16, 2023 7:30 PM Eastern Time

Topic: Dr. Alexandra Yep
Meeting ID:  870 5934 0942
Passcode: astronomy

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