In this two-part talk, I will discuss my instrumentation work in support of the NEID spectrometer and my ongoing research to detect and characterize late-type brown dwarfs. NEID is an optical (380-930 nm), fiber-fed, precision Doppler spectrometer currently in development for the WIYN 3.5 m Telescope at Kitt Peak National Observatory as part of the NASA-NSF Exoplanet Observational Research (NN-EXPLORE) partnership.
Recent advances in stellar magnetometry have revealed that approximately 10% of hot stars host stong, organized surface magnetic fields. Magnetic confinement of the ionized winds of massive, magnetic stars leads to the formation of magnetospheres which, due to their simple, stable fields, share many characteristics with the magnetospheres of giant planets. These magnetospheres can be probed by diagnostics across the electromagnetic spectrum, each of which is sensitive to a different magnetospheric region.
In the last few years rich datasets for cosmic gamma rays (by Fermi-LAT), neutrinos (Ice Cube) and charged Cosmic Rays (CRs) (AMS-02, CALET, DAMPE and HESS) have been published. These measurements are related to the all sky CR energy spectrum, anisotropy and to the gamma-ray emission of individual sources. The interpretation of these data is one of the greatest challenge in modern astroparticle Physics. I will show in my talk that these data can be interpreted as CRs produced and accelerated by Galactic and extragalactic sources and propagating in the Universe.
Low-mass stellar astrophysics has undergone a renaissance over the past two decades. Large surveys have provided statistical samples of these small, dim stars, and the ubiquity of small planets around low-mass stars has reignited interest in their fundamental properties and space weather. In this talk, I will present my work to understand the smallest stars and their stellar and exoplanetary companions. First, I will describe the magnetic activity of M dwarf stars revealed using a large sample of spectroscopically confirmed, high proper motion white dwarf-M dwarf binaries.