Photo of Mr Adam Finley

Mr Adam Finley

Postgraduate

Email:

Project Title:

The Effects of Real Magnetic Field Structures on the Winds from Sun-Like Stars

Research Interests:

I wish to understand the complex interaction of stellar magnetic fields and plasma in stellar winds and other astrophysical fluids. The Sun is observed to undergo a 22 year cycle of magnetic activity, over which time the dipolar field polarity is seen to reverse and then be restored. Through the use of Zeeman Doppler imaging (ZDI) observations, other sun-like stars have been shown to have variability (cyclic or otherwise) in their magnetic fields. Changes in magnetic field geometry should affect the angular momentum loss rates of stellar winds, thus impacting the spin-down of the star, and our predictions for the age of the star (Gyrochronology).

Current Work:

Working in the AWESoMeStars research group, supervised by Sean Matt, I create magnetohydrodynamics (MHD) simulations of stellar winds from sun-like stars, where I explore the impact of imposed magnetic field structures on the morphology and structure within the wind. My research is mainly focused on the creation of torque scaling laws for evolutionary models of stellar spin down, which take into account the changing magnetic field structure seen in many active stars. I have performed a systematic study of the simplest axisymmetric field combinations, dipole, quadrupole and octupole, producing semi-analytic relations for the torque on the star. Following this, I applied these to the variable magnetic field topologies observed for both the Sun and other sun-like stars. I am furthering this work by concidering more complex/realistic magnetic field configurations in my MHD wind simulations.

To better visualise the magnetic fields of solar-like stars (and potentially other magnetised astrophysical phenomena), I have been working with the physics department's 3D printing capability to render handheld models which can be used for research or outreach purposes. 

My personal website can be found here: http://af472.github.io

First Author Publications:

The Effect of Combined Magnetic Geometries on Thermally Driven Winds. I: Interaction of Dipolar and Quadrupolar Fields: 

http://iopscience.iop.org/article/10.3847/1538-4357/aa7fb9

The Effect of Combined Magnetic Geometries on Thermally Driven Winds. II. Dipolar, Quadrupolar, and Octupolar Topologies: 

http://iopscience.iop.org/article/10.3847/1538-4357/aaaab5

The Effect of Magnetic Variability on Stellar Angular Momentum Loss. I: The Solar Wind Torque During Sunspot Cycles 23 & 24: 

http://iopscience.iop.org/article/10.3847/1538-4357/aad7b6

The Effect of Magnetic Variability on Stellar Angular Momentum Loss. II. The Sun, 61 Cygni A, epsilon Eridani, ξ Bootis A, and τ Bootis A: 

https://iopscience.iop.org/article/10.3847/1538-4357/ab12d2

Solar Angular Momentum Loss Over the Past Several Millennia:

https://iopscience.iop.org/article/10.3847/1538-4357/ab3729

Co-Author Publications:

Estimating Magnetic Filling Factors from Zeeman–Doppler Magnetograms - See et al. (2019a): 

https://iopscience.iop.org/article/10.3847/1538-4357/ab1096

Do Non-dipolar Magnetic Fields Contribute to Spin-down Torques? - See et al. (2019b): 

https://arxiv.org/abs/1910.02129

Co-Supervised Summer Student Projects:

  • Amy Hewitt - Direct Detection of Solar Wind Angular Momentum Flux - 2019
  • Siddhant Deshmukh - Long-time Variability of the Solar Angular Momentum Loss Rate - 2018
  • Dean Patient - 3D Printing of Stellar Magnetic Fields - 2017

Teaching Experience:

Postgraduate Teaching Assistant (2016-Present):

  • PHY2021 - Electromagnetism I
  • PHY2022 - Quantum Mechanics I
  • PHY2023 - Thermal Physics
  • PHY2024 - Condensed Matter I

Invited Seminars:

  • "Solar and Stellar Rotation - Current Developments in Wind Braking", Astrophysics Seminar at the DAMTP, University of Cambridge, Oct 2018

Nuggets:

Attended Events:

  • STFC Adv. Summer School in Solar System Plasmas, Lancaster Univeristy, UK, September 2019
  • Bcool 2019 - Presented Talk at University of Exeter, UK, July 2019
  • IAUS354: Solar and Stellar Magnetic Fields: Origins and Manifestations - Presented Poster in Copiapo, Chile, July 2019
  • ISSI Team Meeting "Solar & Stellar Wind Connection", Bern, Switzerland, June 2019
  • Evry Schatzman School "Multi-D Processes in Stellar Physics", Roscoff, France, October 2018 
  • STFC Intro. Summer School in Solar System Plasmas, University of Exeter, UK, August 2018
  • Cool Stars 20 - Presented Poster in Boston, MA, July 2018
  • Internal Seminar -  Presented talk entitled "The Effect of Magnetic Geometry on the Angular Momentum Loss From the Sun and Other Stars", University of Exeter, July 2018
  • Bcool 2018 - Presented Talk at Trinity College Dublin, April 2018
  • BBECss -  Presented talk entitled "The Effect of Magnetic Variability on the Angular Momentum Loss From the Sun and Other Stars", University of Exeter, December 2017
  • 2nd Year Talks - Presented talk entitled 'Rotational Evolution of Sun-Like Stars Due to Their Stellar Winds", University of Exeter, October 2017
  • Ages2 Conference - Presented Poster in Elba, Italy, September 2017
  • Rotation and Activity Mini Meeting - Western Washington University, WA, August 2017
  • IAUS 335: Space Weather of the Heliosphere: Processes and Forecasts - Assisted the LOC, University of Exeter, July 2017
  • Bcool 2017 - Presentation and 3D models in Montpellier, July 2017
  • National Astronomy Meeting 2017 - Presented Poster and 3D models at University of Hull, July 2017
  • Peer-Organised 1st Year Astrophysics Development Day - University of Exeter,  June 2017
  • TOUPIES Wrap-up - Meeting at Universite de Montpelier France, November 2016
  • HPC Methods for Computational Fluid Dynamics and Astrophysics - Workshop at CINECA Bologna Italy, November 2016
  • Star Formation - Conference at Exeter University, September 2016
  • Modern Observations, Theory and Techniques for Solar and Stellar Physics - Meeting at Warwick University, July 2016

Previous Education:

MPhys Physics with Astrophysics and Space Science (2012-2016)