Osborn, J., Wilson, R.W., Dhillon, V.S. orcid.org/0000-0003-4236-9642 et al. (2 more authors) (2011) Conjugate-plane photometry: reducing scintillation in ground-based photometry. Monthly Notices of the Royal Astronomical Society, 411 (2). pp. 1223-1230. ISSN 0035-8711
Abstract
High-precision fast photometry from ground-based observatories is a challenge due to intensity fluctuations (scintillation) produced by the Earth's atmosphere. Here we describe a method to reduce the effects of scintillation by a combination of pupil reconjugation and calibration using a comparison star. Because scintillation is produced by high-altitude turbulence, the range of angles over which the scintillation is correlated is small and therefore simple correction by a comparison star is normally impossible. We propose reconjugating the telescope pupil to a high dominant layer of turbulence, then apodizing it before calibration with a comparison star. We find by simulation that given a simple atmosphere with a single high-altitude turbulent layer and a strong surface layer, a reduction in the intensity variance by a factor of ∼30 is possible. Given a more realistic atmosphere as measured by Scintillation Detection and Ranging (SCIDAR) at San Pedro Mártir, we find that on a night with a strong high-altitude layer we can expect the median variance to be reduced by a factor of ∼11. By reducing the scintillation noise we will be able to detect much smaller changes in brightness. If we assume a 2-m telescope and an exposure time of 30 s, a reduction in the scintillation noise from 0.78 to 0.21 mmag is possible, which will enable the routine detection of, for example, the secondary transits of extrasolar planets from the ground.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2010 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Keywords: | atmospheric effects; techniques: photometric; ATMOSPHERIC INTENSITY SCINTILLATION; GENERALIZED SCIDAR; EXTRASOLAR PLANET; STARS; LAYER; TURBULENCE |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Nov 2017 10:53 |
Last Modified: | 06 Nov 2017 10:53 |
Published Version: | https://doi.org/10.1111/j.1365-2966.2010.17759.x |
Status: | Published |
Publisher: | Oxford University Press |
Refereed: | Yes |
Identification Number: | 10.1111/j.1365-2966.2010.17759.x |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:123526 |