Maximizing Ariel's Survey Leverage for Population-Level Studies of Exoplanets

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Cowan, Nicolas B., Coull-Neveu, Ben
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912687125954560
author Cowan, Nicolas B.
Coull-Neveu, Ben
author_facet Cowan, Nicolas B.
Coull-Neveu, Ben
contents ESA's Ariel mission will be uniquely suited to performing population-level studies of exoplanets. Most of these studies consist of quantifying trends between an Ariel-measured quantity, y, and an a priori planetary property, x; for example, atmospheric metallicity as inferred from Ariel transit spectroscopy vs. planetary mass. The precision with which we can quantify such trends depends on the number of targets in the survey and their variance in the a priori parameter. We define the leverage of a survey with N targets as L = sqrt(N)stdev(x) and show that it quantitatively predicts the precision of population-level trends. The target selection challenge of Ariel can therefore be summarized as maximizing L along some axes of diversity for a given cumulative observing time. To this end, we consider different schemes to select the mission reference sample for a notional three year transit spectroscopy survey with Ariel. We divide the exoplanets in the mission candidate sample into logarithmic classes based on radius, equilibrium temperature and host star temperature. We then construct a target list by cyclically choosing the easiest remaining target in each class. We find that the leverage on a single axis of diversity can be increased by dividing that axis into many classes, but this sacrifices leverage along other axes of diversity. We conclude that a modest number of classes, possibly only one, should be defined when selecting Ariel targets. Lastly, we note that the statistical leverage of the Ariel transit survey would be significantly increased if current candidate planets were confirmed. This highlights the urgency of vetting and confirming the easiest transmission and emission spectroscopy targets in the Ariel mission candidate sample.
format Preprint
id arxiv_https___arxiv_org_abs_2506_06429
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Maximizing Ariel's Survey Leverage for Population-Level Studies of Exoplanets
Cowan, Nicolas B.
Coull-Neveu, Ben
Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
ESA's Ariel mission will be uniquely suited to performing population-level studies of exoplanets. Most of these studies consist of quantifying trends between an Ariel-measured quantity, y, and an a priori planetary property, x; for example, atmospheric metallicity as inferred from Ariel transit spectroscopy vs. planetary mass. The precision with which we can quantify such trends depends on the number of targets in the survey and their variance in the a priori parameter. We define the leverage of a survey with N targets as L = sqrt(N)stdev(x) and show that it quantitatively predicts the precision of population-level trends. The target selection challenge of Ariel can therefore be summarized as maximizing L along some axes of diversity for a given cumulative observing time. To this end, we consider different schemes to select the mission reference sample for a notional three year transit spectroscopy survey with Ariel. We divide the exoplanets in the mission candidate sample into logarithmic classes based on radius, equilibrium temperature and host star temperature. We then construct a target list by cyclically choosing the easiest remaining target in each class. We find that the leverage on a single axis of diversity can be increased by dividing that axis into many classes, but this sacrifices leverage along other axes of diversity. We conclude that a modest number of classes, possibly only one, should be defined when selecting Ariel targets. Lastly, we note that the statistical leverage of the Ariel transit survey would be significantly increased if current candidate planets were confirmed. This highlights the urgency of vetting and confirming the easiest transmission and emission spectroscopy targets in the Ariel mission candidate sample.
title Maximizing Ariel's Survey Leverage for Population-Level Studies of Exoplanets
topic Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2506.06429