Identifying Flare Locations Through Exoplanet Transit Occultations
Loading...
Date
2023-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
The Ohio State University
Abstract
M dwarfs are the most common stars in the galaxy and a popular prospect in searching for
extraterrestrial life. They are quite cool stars and have a high prevalence for hosting rocky
planets, which is what has made them so popular. However, they are not perfect, as these
stars are highly active, with high flare rates, which could also have associated coronal mass
ejections that would be bombarding these planets with radiation and high-energy particles.
The impact of these bombardments is dependent on the latitude in which they are occurring,
yet for M dwarfs, the location of these flares is mostly unknown.
That is the mission of this thesis; to develop a new technique that can be used to constrain
the location of flares through occultation events. As a planet passes in front of an ongoing
flare, we can use its known impact parameter, as well as the timing of the transit, to predict
the geometry of the system, thus revealing the possible latitudes and longitudes in which this
event occurred. I have also worked on predicting the probability of this event being detected
for a number of known systems. An example can be shown for AU Mic b, which for a single
transit has detection a chance of 0.38%, but quickly rises to 1.14 % when considering a full
27-day TESS Sector. This chance is even higher for eclipsing binaries, with CM Draconis
having a 0.978 % chance for one eclipse but a 32.61 % chance during a single TESS sector.
In order to demonstrate this technique, I analyzed two M dwarf eclipsing binary systems,
with an equatorial flare occultation candidate having been identified on CM Draconis. In
addition to this, I also detail how the work being done to understand the flaring behavior of
these stars also led to better characterizing the physical properties of multiple M dwarfs.
Description
Keywords
Flares, M dwarf, stars, transits