Researcher(s)
- Marisol Catalan Olais, Physics, University of Delaware
Faculty Mentor(s)
- Veronique Petit, Physics and Astronomy, University of Delaware
Abstract
Stellar parameters, such as temperature, mass, and luminosity, help differentiate between classes of stars. Classic B-type stars are highly luminous, massive, and hot, giving the star a blue appearance. Bp and Be stars are two classes of B stars that show hydrogen emission in its spectrum due to their accretion disk. Be stars are non-magnetic and have a Keplerian disk, meaning that material closest to the star travels the fastest. However, Bp stars are magnetic and the accretion disk co-rotates with the star, meaning that velocity and distance are proportional to one another. In Bp stars, the velocity of the circumstellar material is typically greater than twice the rotational velocity of the star. My research analyzes two Be stars, HD 51477 and HD 167401, that exhibited characteristics of a massive magnetic star because their hydrogen emission and the velocity of the material orbiting the star was greater than twice its rotational velocity. Therefore, I will determine the upper limit of their magnetic fields through spectropolarimetry, least-squared deconvolved (LSD) profiles, and Bayesian statistics. Spectropolarimetry measures the polarization of light as a function of wavelength. LSD profiles create weighted average line profiles from selected lines and wavelengths of a star’s spectrum. Bayesian analysis helps answer questions using probability statements when the parameters are unknown. So far, both stars appear to have no apparent magnetic field, meaning that the star could be non-magnetic or have a magnetic field that is too weak to measure with current observations and analytical methods. Moving forward, I will analyze both stars using a Python code known as pyRaven to determine the upper limit of the star’s magnetic field using Bayesian analysis.