Noise Sources in Photometry and Radial Velocities

TL;DR

This paper reviews the main astrophysical noise sources affecting photometric and radial velocity exoplanet detection methods, emphasizing their impact and mitigation strategies to improve detection sensitivity.

Contribution

It provides a comprehensive overview of stellar noise sources and discusses techniques to mitigate their effects in exoplanet observations.

Findings

Stellar oscillations significantly affect measurement precision.

Granulation introduces variability that complicates signal detection.

Magnetic activity causes noise that can be mitigated with observational strategies.

Abstract

The quest for Earth-like, extrasolar planets (exoplanets), especially those located inside the habitable zone of their host stars, requires techniques sensitive enough to detect the faint signals produced by those planets. The radial velocity (RV) and photometric transit methods are the most widely used and also the most efficient methods for detecting and characterizing exoplanets. However, presence of astrophysical "noise" makes it difficult to detect and accurately characterize exoplanets. It is important to note that the amplitude of such astrophysical noise is larger than both the signal of Earth-like exoplanets and state-of-the-art instrumentation limit precision, making this a pressing topic that needs to be addressed. In this chapter, I present a general review of the main sources of noise in photometric and RV observations, namely, stellar oscillations, granulation, and magnetic activity. Moreover, for each noise source I discuss the techniques and observational strategies which allow us to mitigate their impact.