The bulk composition of exo-planets

TL;DR

This paper emphasizes the importance of ultraviolet spectroscopy of white dwarfs for directly measuring exo-planetary compositions, highlighting current limitations and the need for advanced space telescopes to improve understanding of planet formation.

Contribution

It underscores the critical role of UV spectroscopy in exo-planet composition analysis and advocates for next-generation telescopes to enhance measurement capabilities.

Findings

UV spectroscopy is currently the only direct method for measuring exo-planet bulk compositions.

Limitations of HST hinder progress, requiring larger aperture space telescopes.

Advancement in UV instrumentation is essential for future exo-planet research.

Abstract

Priorities in exo-planet research are rapidly moving from finding planets to characterizing their physical properties. Of key importance is their chemical composition, which feeds back into our understanding of planet formation. For the foreseeable future, far-ultraviolet spectroscopy of white dwarfs accreting planetary debris remains the only way to directly and accurately measure the bulk abundances of exo-planetary bodies. The exploitation of this method is limited by the sensitivity of HST, and significant progress will require a large-aperture space telescope with a high-throughput ultraviolet spectrograph.