Jeremy Rigney - Student Profile
Current Research Project:
Stellar Flare Observations with the International LOFAR Telescope
My research focuses on the detection and investigation of stellar flares on m-dwarf stars using the International LOFAR Telescope. LOFAR, the LOw Frequency ARray, is a network of radio antenna throughout Europe, utilising Very Long Baseline Interferometry to create the largest low frequency radio telescope in the world, and is observing the universe in the 10-240 MHz regime.
M-Dwarfs (also known as red dwarfs) are the most common type of star in the universe, comprising over 70% of the stellar population. They are classified as being less than 0.6 solar radii, with a surface temperature of between 2500 and 3500 K. Their high angular momentum is thought to generate a large magnetic dynamo, powering the high flare activity on the surface. On some m-dwarfs ‘superflares’ are a regular occurrence, with energies hundreds of times stronger than the highest energy solar flares ever detected. However, little is understood about these processes, or about the levels of emission of plasma and radiation into the stellar atmosphere, known as a Coronal Mass Ejections (CMEs). Observations at low frequencies may be able to constrain these processes by comparing detections to known flare events on the Sun.
Studying these m-dwarfs has implications for the habitability of orbiting exoplanets, and for better understanding the Sun and space weather. If these flares release large amounts of ionising radiation, the atmosphere of planets close to the star may be stripped away. If these flares occur frequently, it may be possible for planets further away to maintain liquid water on their surface. Both of these scenarios lead to the redefinition of a habitable zone around their host star. Furthermore, a detection of a large flare event CME on an m-dwarf with LOFAR may provide a better understanding of how superflares form, and if flares of similar energies can occur on the Sun. This may be helpful for space weather monitoring of the Sun in the future.
I graduated from University College Dublin with a BSc. (Hons.) in Physics with Astronomy and Space Science. I started my PhD in September 2020 as the Eric Lindsay Scholar at the Dublin Institute for Advanced Studies and Armagh Observatory and Planetarium. I am registered as a postgraduate research student at Queen’s University Belfast. I have completed summer internships with University College Dublin and Trinity College Dublin using the I-LOFAR radio telescope, the Irish station of the International LOFAR Telescope. Learning how to operate the telescope and take observations with I-LOFAR introduced me to the area of radio astronomy.
Stellar Physics and Stellar Flares