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State of the Field: Extreme Precision Radial Velocities

Fischer, Debra A. and Howard, Andrew W. (2016) State of the Field: Extreme Precision Radial Velocities. Publications of the Astronomical Society of the Pacific, 128 (964). Art. No. 066001. ISSN 0004-6280.

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The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of the art Doppler precision and identified the critical path challenges for reaching 10 cm s^(−1) measurement precision. The presentations and discussion of key issues for instrumentation and data analysis and the workshop recommendations for achieving this bold precision are summarized here. Beginning with the High Accuracy Radial Velocity Planet Searcher spectrograph, technological advances for precision radial velocity (RV) measurements have focused on building extremely stable instruments. To reach still higher precision, future spectrometers will need to improve upon the state of the art, producing even higher fidelity spectra. This should be possible with improved environmental control, greater stability in the illumination of the spectrometer optics, better detectors, more precise wavelength calibration, and broader bandwidth spectra. Key data analysis challenges for the precision RV community include distinguishing center of mass (COM) Keplerian motion from photospheric velocities (time correlated noise) and the proper treatment of telluric contamination. Success here is coupled to the instrument design, but also requires the implementation of robust statistical and modeling techniques. COM velocities produce Doppler shifts that affect every line identically, while photospheric velocities produce line profile asymmetries with wavelength and temporal dependencies that are different from Keplerian signals. Exoplanets are an important subfield of astronomy and there has been an impressive rate of discovery over the past two decades. However, higher precision RV measurements are required to serve as a discovery technique for potentially habitable worlds, to confirm and characterize detections from transit missions, and to provide mass measurements for other space-based missions. The future of exoplanet science has very different trajectories depending on the precision that can ultimately be achieved with Doppler measurements.

Item Type:Article
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URLURL TypeDescription Paper
Fischer, Debra A.0000-0003-2221-0861
Howard, Andrew W.0000-0001-8638-0320
Additional Information:© 2016 The Astronomical Society of the Pacific. Received 2016 January 21; accepted 2016 February 29; published 2016 May 17. The content of this publication emerged from presentations and discussion by the 150 participants in the Second Workshop on Extreme Precision Radial Velocities, held at Yale University. The talks and posters from this meeting are archived at We thank the anonymous referee for providing an exceptionally careful review of this paper and for many suggested changes which improved the quality of the paper. We are grateful to Yale University, to the National Science Foundation grant AST-1458915 and to the NASA Exoplanet Science Institute (NExScI) for providing financial support that enabled this workshop and provided support for participants. D.A.F. thanks NASA NNX12ACG01 C for inspiring the study of extreme precision RV measurements. R.I.D. acknowledges the Miller Institute at the Univ of California, Berkeley for Basic Research in Science. S.A.D. acknowledges support from NIST and the NSF grant AST-1310875. X.D. would like to thank the Society in Science for its support through a Branco Weiss Fellowship. E.B.F. was supported in part by NASA Exoplanet Research Program award NNX15AE21G. Work by B.S.G. was partially supported by NSF CAREER Grant AST-1056524. G.L. acknowledges support from the NASA Astrobiology Institute through a cooperative agreement between NASA Ames Research Center and the University of California at Santa Cruz, and from the NASA TESS Mission through a cooperative agreement between M.I.T. and UCSC. A.R. acknowledges support from the European Research Council under the FP7 Starting Grant agreement number 279347 and from DFG grant RE 1664/9-1. N.C.S. and P.F. acknowledge support by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UID/FIS/04434/2013 and PTDC/FIS-AST/1526/2014 as well as through Investigador FCT contracts of reference IF/01037/2013 and IF/00169/2012, and POPH/FSE (EC) by FEDER funding through the program "Programa Operacional de Factores de Competitividade—COMPETE." P.F. further acknowledges support from FCT in the form of an exploratory project reference IF/01037/2013CP1191/CT0001. A.S. thanks the Giant Magellan Telescope Organization for their support for much the work described in his contribution to this paper under Contract No. GMT-INS-CON-00584. S.X.W. is supported by a NASA Earth and Space Science Fellowship (NNX14AN81H). S.X.W. and J.T.W. acknowledge support from NSF grant AST-1211441 for the work on telluric contamination. J.T.W. acknowledges NSF grant AST1109727 and NASA grant NNX12AC01G for work on barycentric corrections. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. The PARAS program is fully supported and funded by the Department of Space, Govt. of India and Physical Research Laboratory (PRL), Ahmedabed, India. The PARAS team would like to acknowledge the support of the Director, PRL, and the Mt. Abu Observatory staff for running the program and Francesco Pepe (Geneva Observatory) and Larry Ramsey (Pen State University) for many scientific and technical inputs. Two of the PARAS team members, Suvrath Mahadevan and Arpita Roy would like to thank the Centre of Exoplanets and Habitable Worlds at Penn State University for their partial support. The McDonald Observatory planet search is currently supported by the National Science Foundation under Astrophysics grant AST-1313075, and has been supported in the past by various NASA grants.
Funding AgencyGrant Number
Yale UniversityUNSPECIFIED
NASA Exoplanet Science InstituteUNSPECIFIED
University of California BerkeleyUNSPECIFIED
National Institute of Standards and Technology (NIST)UNSPECIFIED
Society in ScienceUNSPECIFIED
NASA Astrobiology InstituteUNSPECIFIED
European Research Council (ERC)279347
Deutsche Forschungsgemeinschaft (DFG)RE 1664/9-1
Fundação para a Ciência e a Tecnologia (FCT)UID/FIS/04434/2013
Fundação para a Ciência e a Tecnologia (FCT)PTDC/FIS-AST/1526/2014
Fundação para a Ciência e a Tecnologia (FCT)IF/01037/2013
Fundação para a Ciência e a Tecnologia (FCT)IF/00169/2012
Fondo Europeo de Desarrollo Regional (FEDER)UNSPECIFIED
Fundação para a Ciência e a Tecnologia (FCT)IF/01037/2013CP1191/CT0001
Giant Magellan Telescope OrganizationGMT-INS-CON-00584
NASA Earth and Space Science FellowshipNNX14AN81H
Pennsylvania State UniversityUNSPECIFIED
Eberly College of ScienceUNSPECIFIED
Pennsylvania Space Grant ConsortiumUNSPECIFIED
Government of IndiaUNSPECIFIED
Physical Research LaboratoryUNSPECIFIED
Miller Institute for Basic Research in ScienceUNSPECIFIED
Subject Keywords:instrumentation: spectrographs – methods: observational – methods: statistical – techniques: radial velocities – techniques: spectroscopic
Issue or Number:964
Record Number:CaltechAUTHORS:20170619-160100148
Persistent URL:
Official Citation:Debra A. Fischer et al 2016 PASP 128 066001
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:78346
Deposited By: Tony Diaz
Deposited On:20 Jun 2017 15:20
Last Modified:09 Mar 2020 13:18

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