Dr. Trygve Prestgard

Project

What is the flux of extraterrestrial material to Earth composed of and did it change with time?

Research summary

Current position: The Earth is exposed to large abundances of interplanetary material, mostly in the form of sub-millimetric particles. A subset of these particles reach the surface as micrometeorites (MMs). MMs are thought to predominantly reflect material ejected from small bodies in the Asteroid Belt (e.g. through impact events) that eventually spiralled towards the Inner Solar System. Consequently, understanding the flux of MMs over time can provide insight into the Solar System's collisional history. Although MMs were traditionally assumed to be too fragile to withstand long-term weathering processes, fossil MMs have been recovered in sediments dating back hundreds of millions of years. My post-doctorate position here at VUB is focused on extracting fossil MMs from sediments (covering the Phanerozoic) and to deduce their flux over time. This information will be compared to known asteroid breakup events and Earth impact craters, as well as extinction events and past temperature anomalies (to see whether a link may exist). I additionally seek for micrometeorites in desert sand. 

Education:

• - PhD in Earth and Space sciences, Université Grenoble Apes, France, 2023
• - MSc in Earth sciences, Université Grenoble Apes, France, 2019
• - BSc in Earth sciences, Université Grenoble Apes, France, 2017

Prior to my work at the VUB I was a PhD student at Université Grenoble Alpes (UGA) working on the spectroscopic properties of planetary materials (Optical-IR, Raman). The project focused on carbonaceous chondrites, particularly CM, CO, CR, CI and Tagish Lake-resembling chondrites. The purpose of these measurements was to better understand establish a meteorite-asteroid link, as well as their geological history. I follow-up my spectral data with petrographic and geochemical analysis, the latter of which were conducted at CEREGE (Université Aix-Marseille) and at G-time laboratory (Université Libre de Bruxelles), respectively. 

Outside professional settings, I am an amateur astronomer with a particular interest in data mining. Most notably, I use photometric, astrometric and online survey imagery to “hunt” for previously uncatalogued small bodies or deep sky objects. Among them include 130 comets found via the Sungrazer Project. I’ve also used data from the Gaia, Digitalised Sky Survey (DSS), Sloan Digital Sky Survey (SDSS), and the late Wide-field Infrared Survey Explorer (WISE) to search for (proto)planetary nebulae, star clusters, multiple and variable stars (more details on my personal website).

Other than “sky hunting”, I also enjoy discussing the literature of already-known objects, whether it be the classification and geological history of certain meteorites, the nature of planetary nebula candidates or the physical nature of multiple stars. These “discussions” are either in the format of blog posts on my personal website or short papers published in the Journal of Double Star Observations (JDSO). 

• Personal analysis on the secondary history of CM2 chondrite Dominion Range 10121: https://skyhuntblog.wordpress.com/2024/03/03/the-post-accretional-history-of-dom-10121-a-recently-classified-cm2-chondrite/
• Personal analysis of three planetary nebula candidates: https://skyhuntblog.wordpress.com/2019/11/29/mul-ir-56-mul-ir-58-and-mul-ir-62-true-planetary-nebulae/
• Review of Ferrero 32, a group of stars that resemble a quadruple star system: 

Prestgard, T. (2019). Study on the Apparent Multiple Nature of Ferrero 32. Journal of Double Star Observations, 15(1), 172-173: http://www.jdso.org/volume15/number1/Prestgard_172_173.pdf

Lastly, I also enjoy hiking! The outdoors is a great way of resourcing oneself for a productive week of work!