@inproceedings{9361bb464613415f93e7d507e6545d42,
title = "First faint Dual-Field Phase-Referenced observations on the Keck Interferometer",
abstract = "Ground-based long baseline interferometers have long been limited in sensitivity by the short integration periods imposed by atmospheric turbulence. The first observation fainter than this limit was performed on January 22, 2011 when the Keck Interferometer observed a K=11.5 target, about one magnitude fainter than its K=10.3 limit. This observation was made possible by the Dual Field Phase Referencing instrument of the ASTRA project: simultaneously measuring the real-time effects of the atmosphere on a nearby bright guide star, and correcting for it on the faint target, integration time longer than the turbulence time scale are made possible. As a prelude t{\'o}this demonstration, we first present the implementation of Dual Field Phase Referencing on the interferometer. We then detail its on-sky performance focusing on the accuracy of the turbulence correction, and on the resulting fringe contrast stability. We conclude with a presentation of early results obtained with Laser Guide Star AO and the interferometer.",
keywords = "Dual field phase referencing, Laser guide star adaptive optics, Optical long baseline interferometry",
author = "J. Woillez and P. Wizinowich and R. Akeson and M. Colavita and J. Eisner and R. Millan-Gabet and J. Monnier and Pott, {J. U.} and S. Ragland and E. Appleby and A. Cooper and C. Felizardo and J. Herstein and O. Martin and D. Medeiros and D. Morrison and T. Panteleeva and B. Smith and K. Summers and K. Tsubota and C. Tyau and E. Wetherell",
year = "2012",
doi = "10.1117/12.926404",
language = "English (US)",
isbn = "9780819491466",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Optical and Infrared Interferometry III",
note = "Optical and Infrared Interferometry III ; Conference date: 01-07-2012 Through 06-07-2012",
}