Young Stars Amid External Radiation and Colliding Associations

Alexandra Yep is a poet turned astronomer. She first shared her research of The Gum Nebula and young stars as part of The Martz-Kohl Observatory Lecture Series in October, 2020. She has continued her research and work. The observatory was honored to host her Ph.D. dissertation defense on 07 July 2021. Along the way, she discovered several star clusters in the Gum Nebula which are now known as Yep-1, Yep-2 and Yep-3. She also deduced that two distinct stellar associations are in the process of “colliding”. While her dissertation is about 250 pages of detailed mathematics, observations, charts and simulations, Ms. Yep managed to condense the highlights into an hour presentation- before Q&A 🙂

Stars are not born in isolation. They exist in the company of other stars and potentially other clusters of stars and are thus subject to both star-star and cluster-cluster interactions. In this thesis, Ms. Yep explores both phenomena in the Gum Nebula, a diffuse H ii region in the constellations of Vela and Puppis. The hot stars ζ Pup and γ2 Vel powering the Gum Nebula shine so intensely that their ultraviolet light photoevaporates dense cloud cores into comet-like shapes, called cometary globules. The radiation can disperse young stars’ protoplanetary disks up to a hundred light years away, hastening disk evolution and possibly impeding planet formation.clusters.

© 2021 by Alexandra Yep


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