The stellar scintillation on large and extremely large telescopes

Abstract

The accuracy of ground-based astronomical photometry is limited by two factors: photon statistics and stellar scintillation arising when star light passes through Earth's atmosphere. This paper examines the theoretical role of the outer scale $L_0$ of the optical turbulence (OT) which suppresses the low-frequency component of scintillation. It is shown that for typical values of $L_0\sim 25-50$ m, this effect becomes noticeable for a telescopes of diameter around 4 m. On extremely large, $30-40$ m, telescopes with exposures longer than a few seconds, the inclusion of the outer scale in the calculation reduces the scintillation power by more than a factor of 10 relative to conventional estimates. The details of this phenomenon are discussed for various models of non-Kolmogorov turbulence. Also, a quantitative description of the influence of the telescope central obscuration on the measured scintillation noise is introduced and combined with the effect of the outer scale. Evaluation of the scintillation noise on the future TMT and E-ELT telescopes, predicts an amplitude of approximately $10 \mumag$ for a 60 s exposures.

Accepted for publication in MNRAS, 10 pages, 9 figures

References in corpus (4)

• Atmospheric scintillation at Dome C, Antarctica: implications for photometry and astrometry
• Testing turbulence model at metric scales with mid-infrared VISIR images at the VLT
• The statistics of the photometric accuracy based on MASS data and the evaluation of high-altitude wind
• Angular correlation of the stellar scintillation on large telescopes

Cited by in corpus (5)

• Atmospheric Scintillation in Astronomical Photometry
• Scintillation correction for astronomical photometry on large and extremely large telescopes with tomographic atmospheric reconstruction
• Comparison of the scintillation noise above different observatories measured with MASS instruments
• Flickers, Bursts, and Dips: Detecting Rapid Variability with the g(2) Autocorrelation Function
• Using chromatic covariance to correct for scintillation noise in ground-based spectrophotometry