# The Chemical Composition of an Extrasolar Kuiper-Belt-Object

## TL;DR

This paper reports the discovery of extrasolar Kuiper Belt-like objects accreting onto a white dwarf, revealing their composition including nitrogen, and suggesting such objects could deliver volatiles to planets in other systems.

## Contribution

First detection of a Kuiper Belt analog's debris in an extrasolar system, including nitrogen, indicating similar objects exist around other stars.

## Key findings

- Detected heavy elements including nitrogen in debris
- Nitrogen mass fraction similar to comet Halley
- Accreted mass estimated at 10^22 grams

## Abstract

The Kuiper Belt of our solar system is a source of short-period comets that may have delivered water and other volatiles to Earth and the other terrestrial planets. However, the distribution of water and other volatiles in extrasolar planetary systems is largely unknown. We report the discovery of an accretion of a Kuiper-Belt-Object analog onto the atmosphere of the white dwarf WD 1425+540. The heavy elements C, N, O, Mg, Si, S, Ca, Fe, and Ni are detected, with nitrogen observed for the first time in extrasolar planetary debris. The nitrogen mass fraction is $\sim$ 2\%, comparable to that in comet Halley and higher than in any other known solar system object. The lower limit to the accreted mass is $\sim$ 10$^{22}$ g, which is about one hundred thousand times the typical mass of a short-period comet. In addition, WD 1425+540 has a wide binary companion, which could facilitate perturbing a Kuiper-Belt-Object analog into the white dwarf's tidal radius. This finding shows that analogs to objects in our Kuiper Belt exist around other stars and could be responsible for the delivery of volatiles to terrestrial planets beyond