Unraveling the anomalous magnetic fields and chemical abundances of AP/BP STARS via industrial scale spectroscopy

The National Science Foundation's Division of Astronomical Sciences awarded $532,746 under the Mathematical and Physical Sciences program (CFDA 47.049) to the Monterey Institute for Research in Astronomy for a three-year project grant beginning October 1, 2025. The award supports the development of a comprehensive catalog of chemically peculiar AP (Ap/Bp) stars through analysis of infrared spectroscopic data from the Sloan Digital Sky Survey/Apache Point Observatory Galactic Evolution Experiment (SDSS/APOGEE). Using machine learning techniques applied to high-resolution, near-infrared spectra, the project will identify and characterize thousands of AP stars to determine their stellar parameters, chemical abundances, magnetic field strengths, and binary properties. The research includes follow-up observations using Mira facilities and Transiting Exoplanet Survey Satellite (TESS) light curves to measure magnetic field strengths and analyze stellar variability, with results compiled into a public-facing catalog for the broader astronomical community.

This project directly addresses fundamental questions regarding stellar magnetic field formation and stellar evolution mechanisms, with particular emphasis on testing the hypothesis that AP stars originate from stellar mergers. The award incorporates significant educational components, including hands-on research experiences for high school and early college interns and the development of public spectroscopic workshops for amateur astronomers and underserved communities. No subawards are planned under this grant structure.

Abstract

This award investigates a class of STARS known as AP STARS, which are chemically peculiar and possess unusually strong magnetic fields. Understanding how these magnetic fields form will provide key insights into how STARS evolve and interact over time. Using a large, uniform dataset of infrared spectra, this study will identify and analyze thousands of AP STARS to test whether their magnetic fields may result from stellar mergers. The research will also involve students, offering hands-on research experiences that can inspire future careers in science, technology, engineering, and mathematics (STEM). This award will support the development of a homogeneous and statistically significant catalog of chemically peculiar AP STARS observed by the sdss/apogee survey and to determine their stellar parameters, chemical abundances, magnetic field strengths, and binary properties. The investigators will utilize high-resolution, near-infrared spectra and machine learning techniques to classify AP STARS and to measure their parameters uniformly. Multi-epoch radial velocity measurements will be used to estimate binary fractions and test the hypothesis that AP STARS originate from stellar mergers. Follow-up observations using mira facilities will characterize magnetic field strengths through spectral line splitting and analyze variability using tess light curves. The resulting catalog will be made available to the broader astronomical community. High school and early college student interns will participate in the research program and in the development of public-facing spectroscopic workshops aimed at local amateur astronomers and underserved communities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are not planned for this award.