Poster Presentation

Probing early angular-momentum loss in intermediate-mass pre-main-sequence stars in the Trumpler 14 open cluster

Author(s): Khushboo K. Rao (Institute of Astronomy, National Central University, Taiwan), Wen-Ping Chen (Institute of Astronomy, National Central University, Taiwan), Hsiang-Yu Chen (Institute of Astronomy, National Central University, Taiwan), Kristen Dage (International Centre for Radio Astronomy Research – Curtin University, Australia), Stella S. R. Offner (University of Texas, Austin, Texas, USA)

Presenter: Khushboo Kunwar Rao (Institute of Astronomy, National Central University, Taiwan)

The angular-momentum evolution of low-mass pre-main-sequence stars is commonly linked to star–disk interactions, magnetically driven outflows, and magnetic activity. For intermediate-mass stars (1.5–8 M☉), however, the relevant processes remain less well understood, and these stars exhibit a wide range of rotational velocities. Such variations in rotation rates can broaden the color-magnitude diagrams of young and intermediate-age clusters, potentially mimicking an extended star-formation history. Several mechanisms have been proposed to explain the observed distribution of rotation rates, but their relative importance remains uncertain. In this work, we investigate the rotational evolution of intermediate-mass pre-main-sequence stars in the young star-forming cluster Trumpler 14. We examine the relationships between stellar rotation, disk signatures, and X-ray emission to explore whether star-disk interactions and magnetic processes regulate their early angular-momentum evolution. We present the observed trends among these properties and assess whether they provide evidence for substantial angular-momentum loss before the stars reach the main sequence.