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Tracking faint fringes with the CHARA-Michigan Phasetracker (CHAMP)

Monnier, John D. and Baron, F. and Anderson, M. and Kraus, S. and Millan-Gabet, R. and Pedretti, E. and Che, X. and ten Brummelaar, T. and Calvet, N. (2012) Tracking faint fringes with the CHARA-Michigan Phasetracker (CHAMP). In: Optical and Infrared Interferometry III. Proceedings of SPIE. No.8445. Society of Photo-Optical Instrumentation Engineers , Bellingham, WA, Art. No. 84451I. ISBN 978-0-8194-9146-6.

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The CHARA-Michigan Phasetracker (CHAMP) successfully tracks fringes in 4-telescope and 6-telescope modes when observing high-visibility targets. We have found that our primary targets (Young Stellar Objects) have unexpectedly low visibility fringes (<20%) for most baselines at CHARA, generally below our tracking thresholds. We have undertaken an upgrade cycle in 2011-2012 to re-optimize CHAMP to allow group-delay tracking on the faintest fringes possible. We describe our multi-pronged strategy using special dicroics, new piezo scanners, and our first attempts to explore CHARA J-band made possible by using special metrology-blocking laser filters. CHAMP can now be used with all the combiners at CHARA.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Monnier, John D.0000-0002-3380-3307
Baron, F.0000-0002-8376-8941
Kraus, S.0000-0001-6017-8773
Millan-Gabet, R.0000-0003-0447-5866
ten Brummelaar, T.0000-0002-0114-7915
Calvet, N.0000-0002-3950-5386
Additional Information:© 2012 SPIE. This work has been supported by the University of Michigan, the National Science Foundation (NSF-ST-0352723, 0707927, 0807577, 1108963) and NASA (NRA-NNG04GC00G). Thanks also to UM machinist Scott Webster, UM undergrad Phil Muirhead, former UM postdoctoral fellow David Berger, and the whole CHARA array team that makes science with MIRC/CHAMP possible.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
University of MichiganUNSPECIFIED
Subject Keywords:interferometry, infrared, fringe tracking, chara, champ
Series Name:Proceedings of SPIE
Issue or Number:8445
Record Number:CaltechAUTHORS:20161024-150646548
Persistent URL:
Official Citation:John D. Monnier ; F. Baron ; M. Anderson ; S. Kraus ; R. Millan-Gabet ; E. Pedretti ; X. Che ; T. ten Brummelaar ; N. Calvet; Tracking faint fringes with the CHARA-Michigan Phasetracker (CHAMP). Proc. SPIE 8445, Optical and Infrared Interferometry III, 84451I (September 12, 2012); doi:10.1117/12.926399
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:71404
Deposited By: Tony Diaz
Deposited On:24 Oct 2016 22:18
Last Modified:03 Oct 2019 16:07

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