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Minimization of non-common path aberrations at the Palomar telescope using a self-coherent camera

Galicher, R. and Baudoz, P. and Delorme, J.-R. and Mawet, D. and Bottom, M. and Wallace, J. K. and Serabyn, E. and Shelton, C. (2019) Minimization of non-common path aberrations at the Palomar telescope using a self-coherent camera. Astronomy and Astrophysics, 631 . Art. No. A143. ISSN 0004-6361. doi:10.1051/0004-6361/201936282.

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Context. The two main advantages of exoplanet imaging are the discovery of objects in the outer part of stellar systems, which constrains the models of planet formation, and its ability to spectrally characterize the planets to study their atmospheres. It is, however, challenging because exoplanets are up to 10¹⁰ times fainter than their stars and are separated by a fraction of an arcsecond. Current instruments like SPHERE-VLT or GPI-Gemini detect young and massive planets only because of non-common path aberrations (NCPA) that are not corrected by the adaptive optics system. To probe fainter exoplanets a new instruments capable of minimizing the NCPA is needed. One solution is the self-coherent camera (SCC) focal plane wavefront sensor which is able to attenuate the starlight by factors of up to several 10⁸ in the laboratory in space-like conditions. Aims. In this paper, we demonstrate the SCC on the sky for the first time. Methods. We installed an SCC on the stellar double coronagraph instrument at the Hale telescope. We minimize the NCPA that limited the vortex coronagraph performance. We then compared this procedure to the standard procedure used at Palomar. Results. On internal sources, we demonstrated that the SCC improves the coronagraphic detection limit by a factor of 4–20 between 1.5 and 5 λ/D. Using this SCC calibration, the on-sky contrast is improved by a factor of 5 between 2 and 4 λ/D. These results prove the ability of the SCC to be implemented in an existing instrument. Conclusions. This paper highlights two interests of the self-coherent camera. First, the SCC can minimize the speckle intensity in the field of view, especially the ones that are very close to the star where many exoplanets are to be discovered. Then the SCC has a 100% efficiency with science time as each image can be used for both science and NCPA minimization.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Mawet, D.0000-0002-8895-4735
Bottom, M.0000-0003-1341-5531
Shelton, C.0000-0001-8982-1654
Additional Information:© 2019 R. Galicher et al. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Received 10 July 2019; Accepted 16 September 2019; Published online 07 November 2019. The authors thank the Région Île-de-France and the Science Council of the Paris Observatory for their support of this work.
Group:Astronomy Department
Funding AgencyGrant Number
Région Île-de-FranceUNSPECIFIED
Paris ObservatoryUNSPECIFIED
Subject Keywords:instrumentation: adaptive optics – instrumentation: high angular resolution – techniques: high angular resolution
Record Number:CaltechAUTHORS:20191119-102223823
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Official Citation:Minimization of non-common path aberrations at the Palomar telescope using a self-coherent camera. R. Galicher, P. Baudoz, J.-R. Delorme, D. Mawet, M. Bottom, J. K. Wallace, E. Serabyn and C. Shelton. A&A, 631 (2019) A143 DOI:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:99929
Deposited By: Tony Diaz
Deposited On:19 Nov 2019 19:13
Last Modified:16 Nov 2021 17:50

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