Front‐ vs. back‐illuminated CCD cameras for photometric surveys: a noise budget analysis

• Published in: Astronomische Nachrichten
• Main Authors: Crouzet, N., Guillot, T., Fressin, F., Blazit, A., the A STEP team
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2007
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/asna.200710820; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fasna.200710820; https://onlinelibrary.wiley.com/doi/pdf/10.1002/asna.200710820

Abstract Exoplanetary transit and stellar oscillation surveys require a very high precision photometry. The instrumental noise has therefore to be minimized. First, we perform a semi‐analytical model of different noise sources. We show that the noise due the CCD electrodes can be overcome using a Gaussian PSF (Point Spread Function) of full width half maximum larger than 1.6 pixels. We also find that for a PSF size of a few pixels, the photometric aperture has to be at least 2.5 times larger than the PSF full width half maximum. Then, we compare a front‐ with a back‐illuminated CCD through a Monte‐Carlo simulation. Both cameras give the same results for a PSF full width half maximum larger than 1.5 pixels. All these simulations are applied to the A STEP (Antarctica Search for Transiting Extrasolar Planets) project. As a result, we choose a front‐illuminated camera for A STEP because of its better resolution and lower price, and we will use a PSF larger than 1.6 pixels. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)