individual
What campus are you from?
Daytona Beach
Authors' Class Standing
Skylar Butler, Senior
Lead Presenter's Name
Skylar Butler
Faculty Mentor Name
Ted von Hippel
Abstract
We expand upon our previous analysis of NGC 2168 (M35), which investigated the precision of isochrone-based age determination for individual main-sequence stars using photometric modeling. Building on that earlier framework, we now assess how inferred stellar ages change when each object is modeled under the assumption that it may possess an unresolved binary companion. Using post burn in posterior samples from the same dataset, we computed the mean Stage 3 ages for more than 3,000 cluster members with binaries turned on, allowing a direct comparison to our prior results with binaries turned off. The resulting age distribution peaks near 2.1 Gyr, with a 68 percent confidence range of 0.98–2.53 Gyr. A vertical reference line marking the published cluster age of log(age)=8.098 (≈126 Myr) from Childs et al. (2024, ApJ 962, 41) falls well to the left of the dominant peak, demonstrating how binary assumptions can substantially broaden and shift posterior age estimates. The older inferred population reflects flux blending from unresolved companions, which mimics evolutionary aging in turn-off and main-sequence stars. This work highlights that the inclusion of binaries in stellar population modeling significantly alters both the precision and the apparent evolutionary state of cluster members, underscoring the importance of binary-aware methods in refining open-cluster age determinations.
Did this research project receive funding support from the Office of Undergraduate Research.
Yes, Spark Grant
Included in
External Galaxies Commons, Other Astrophysics and Astronomy Commons, Physical Processes Commons, Stars, Interstellar Medium and the Galaxy Commons
How Hidden Companions Skew Stellar Ages: A Binary-Inclusive Analysis of NGC 2168
We expand upon our previous analysis of NGC 2168 (M35), which investigated the precision of isochrone-based age determination for individual main-sequence stars using photometric modeling. Building on that earlier framework, we now assess how inferred stellar ages change when each object is modeled under the assumption that it may possess an unresolved binary companion. Using post burn in posterior samples from the same dataset, we computed the mean Stage 3 ages for more than 3,000 cluster members with binaries turned on, allowing a direct comparison to our prior results with binaries turned off. The resulting age distribution peaks near 2.1 Gyr, with a 68 percent confidence range of 0.98–2.53 Gyr. A vertical reference line marking the published cluster age of log(age)=8.098 (≈126 Myr) from Childs et al. (2024, ApJ 962, 41) falls well to the left of the dominant peak, demonstrating how binary assumptions can substantially broaden and shift posterior age estimates. The older inferred population reflects flux blending from unresolved companions, which mimics evolutionary aging in turn-off and main-sequence stars. This work highlights that the inclusion of binaries in stellar population modeling significantly alters both the precision and the apparent evolutionary state of cluster members, underscoring the importance of binary-aware methods in refining open-cluster age determinations.