Comparison of the scintillation noise above different observatories measured with MASS instruments

TL;DR

This study compares scintillation noise at 11 observatories worldwide using MASS instruments, revealing its dependence on atmospheric turbulence and wind, and highlighting seasonal and short-term variability in ground-based photometry.

Contribution

It provides the first extensive statistical comparison of scintillation noise across multiple observatories using MASS data, and evaluates classical formulas against observed values.

Findings

Scintillation noise is mainly influenced by upper atmospheric turbulence and wind.

Mauna Kea exhibits slightly lower scintillation noise, while Tolonchar shows the highest.

Classical Young's formula underestimates actual scintillation noise.

Abstract

Scintillation noise is a major limitation of ground base photometric precision. An extensive dataset of stellar scintillation collected at 11 astronomical sites world-wide with MASS instruments was used to estimate the scintillation noise of large telescopes in the case of fast photometry and traditional long-exposure regime. Statistical distributions of the corresponding parameters are given. The scintillation noise is mostly determined by turbulence and wind in the upper atmosphere and comparable at all sites, with slightly smaller values at Mauna Kea and largest noise at Tolonchar in Chile. We show that the classical Young's formula under-estimates the scintillation noise.The temporal variations of the scintillation noise are also similar at all sites, showing short-term variability at time scales of 1 -- 2 hours and slower variations, including marked seasonal trends (stronger scintillation and less clear sky during local winter). Some correlation was found between nearby observatories.