
Lowell Obervatory
PI of multiple proposals to use the Perkins 72" to track transits of WD 1145+017
MSI Postdoctoral Fellow
McGill Space Institute (MSI)
asteele 'at' physics 'dot' mcgill 'dot' ca
I study gas and dust around stars like the sun and much older.
Debris disks around main sequence stars, dust formation from planet engulfment by giant stars,
stellar mass loss by super giant stars, and the tidal disruption of exoplanetary material by white dwarfs,
all inform our knowledge of the composition of the remnants of stellar formation.
Debris disks around main sequence stars are generated through the collisions of planetesimals that are remnants of stellar evolution. Spatially resolved observations are crucial to characterize the structure of the dust disk and break degeneracies inherent in SED modeling. Using submillimeter wavelength observations I show that gas-poor debris disks around solar analogues generally exhibit properties consistent with scaled-up versions of the Solar System's Kuiper Belt.
Paper:
Resolved mm-wavelength observations of debris disks
Poster:
AAS2016
Dust around giants is also very cool. Check out my poster below!
Poster:
AAS2018
If an exo-asteroid or exo-planet were to get too close to a compact object like a white dwarf, the remnant of evolution for ~95% of stars, it could be ripped apart due to tidal forces. If the geometry is just right, we might see the distrupted pieces transit the white dwarf. This is the case for a number of systems, most notable WD 1145+017.
Poster:
AAS2017
If a WD is in the process of ripping apart an exoplanetary body, light that interacts with the resulting gas would reveal the chemical composition of the disrupted body through an absorption and/or emission spectrum (WD spectra typically contain only H or He absorption lines that are gravitationally redshifted). Features from elements heavier than H or He (i.e., metals) in WD spectra are thought to originate from planetary system material. The existence of WDs with metals in their photospheres and evidence of circumstellar gas tied to the tidal disruption of a planetesimal, has provided a new method to determine the composition of extrasolar planetary bodies.
Paper:
A Characterization of the Circumstellar Gas around WD 1124-293 using Cloudy
Poster:
AAS2019
I am a big fan of observing! I want all of the data all the time. Light is awesome.
PI of multiple proposals to use the Perkins 72" to track transits of WD 1145+017
PI of 2 proposals to observe dust around post main sequence stars
PI of proposal to observe gas around WD 1145+017
Also a Keck Visiting Scholar in 2019
PI of multiple proposals to track transits of WD 1145+017
Graduate Resources Advancing Diversity with Maryland Astronomy and Physics (GRAD-MAP) is a diversity
initiative
at the University of Maryland in the Astronomy and Physics departments.
I was the team lead of this program for two years and served as an advisor for one year.
There are three main parts to the program: fall outreach/collaboration, a Winter Workshop, and a Summer Research Experience.
Created and executed the Open House Event
Organized and ran a 10-day workshop including finding ~5 mentors to work with students, setting up field trips to national labs, and scheduling a weekend of events.
Organized and ran a 10-week a paid summer research experience for GRAD-MAP alumni.
Served on the council for 5 years
Participated in interviews of potential graduate students for 2 years
Graduate representative on the committee to elect a new department chair.
Organized events for the astronomy graduate students to help improve comradery and morale.
A department position akin to a graduate student vice president.
Selected to participate in a panel discussion about service as a graduate student.