EXPRES: a next generation RV spectrograph in the search for earth-like worlds

Jurgenson, C. A.; Fischer, Debra A.; McCracken, Tyler; Sawyer, David; Szymkowiak, Andrew E.; Davis, Allen B.; Muller, Gary; Santoro, Fernando

doi:10.1117/12.2233002

Cited by 133 publications

(79 citation statements)

References 17 publications

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“…The detections of H, Na and Fe presented here add to a constantly growing list of detections in different wavelength regimes and at different spectral resolutions. Current and forthcoming generations of high-resolution optical spectrographs, including HARPS, HARPS-N, and the recently commissioned ESPRESSO (Pepe et al 2013) and EXPRES (Jurgenson et al 2016), offer great potential for such studies, in pursuit of characterizing new planets, and in search of new and insightful chemistry.…”

Section: Resultsmentioning

confidence: 99%

Detection of neutral atomic species in the ultra-hot Jupiter WASP-121b

Cabot

Madhusudhan

Welbanks

et al. 2020

Monthly Notices of the Royal Astronomical Society

100

106

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The class of ultra-hot Jupiters comprises giant exoplanets undergoing intense irradiation from their host stars. They have proved to be a particularly interesting population for their orbital and atmospheric properties. One such planet, WASP-121 b, is in a highly misaligned orbit close to its Roche limit, and its atmosphere exhibits a thermal inversion. These properties make WASP-121 b an interesting target for additional atmospheric characterization. In this paper, we present analysis of archival high-resolution optical spectra obtained during transits of WASP-121 b. Artifacts from the Rossiter-McLaughlin effect and Center-to-Limb Variation are deemed negligible. However, we discuss scenarios where these effects warrant more careful treatment by modeling the WASP-121 system and varying its properties. We report a new detection of atmospheric absorption from Hα in the planet with a transit depth of 1.87 ± 0.11%. We further confirm a previous detection of the Na I doublet, and report a new detection of Fe I via cross-correlation with a model template. We attribute the Hα absorption to an extended Hydrogen atmosphere, potentially undergoing escape, and the Fe I to equilibrium chemistry at the planetary photosphere. These detections help to constrain the composition and chemical processes in the atmosphere of WASP-121 b.

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Section: Resultsmentioning

confidence: 99%

Detection of neutral atomic species in the ultra-hot Jupiter WASP-121b

Cabot

Madhusudhan

Welbanks

et al. 2020

Monthly Notices of the Royal Astronomical Society

100

106

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“…For PRV instruments this is a very fundamental issue, and while recently has been discussed in some papers 18,21,22,23 there is yet a fully dedicated study to be written on the topic. While this present paper did not discuss the optics in detail, we refer to the accompanying WISDOM optical design paper 12 , as we feel the issue is important enough to be listed here in this section.…”

Section: Effect Of Optical Design On Sub-m/s Radial Velocitiesmentioning

confidence: 99%

“…After the re-introduction of this idea by the G-CLEF instrument 18 some recent PRV spectrographs 23 also employ this solution, and in our opinion it should be considered by other recent/future designs due to its significant benefits.…”

Section: Optical Design Choicesmentioning

confidence: 99%

WISDOM: the WIYN spectrograph for Doppler monitoring: a NASA-NSF concept for an extreme precision radial velocity instrument in support of TESS

Fürész

Simcoe

Barnes³

et al. 2016

SPIE Proceedings

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The Kepler mission highlighted that precision radial velocity (PRV) follow-up is a real bottleneck in supporting transiting exoplanet surveys. The limited availability of PRV instruments, and the desire to break the "1 m/s" precision barrier, prompted the formation of a NASA-NSF collaboration 'NN-EXPLORE' to call for proposals designing a new Extreme Precision Doppler Spectrograph (EPDS). By securing a significant fraction of telescope time on the 3.5m WIYN at Kitt Peak, and aiming for unprecedented long-term precision, the EPDS instrument will provide a unique tool for U.S. astronomers in characterizing exoplanet candidates identified by TESS. One of the two funded instrument concept studies is led by the Massachusetts Institute of Technology, in consortium with Lincoln Laboratories, Harvard-Smithsonian Center for Astrophysics and the Carnegie Observatories. This paper describes the instrument concept WISDOM (WIYN Spectrograph for DOppler Monitoring) prepared by this team.WISDOM is a fiber fed, environmentally controlled, high resolution (R=110k), asymmetric white-pupil echelle spectrograph, covering a wide 380-1300nm wavelength region. Its R4 and R6 echelle gratings provide the main dispersion, symmetrically mounted on either side of a vertically aligned, vacuum-enclosed carbon fiber optical bench. Each grating feeds two cameras and thus the resulting wavelength range per camera is narrow enough that the VPHG cross-dispersers and employed anti-reflection coatings are highly efficient. The instrument operates near room temperature, and so thermal background for the near-infrared arm is mitigated by thermal blocking filters and a short (1.7µm) cutoff HgCdTe detector. To achieve high resolution while maintaining small overall instrument size (100/125mm beam diameter), imposed by the limited available space within the observatory building, we chose to slice the telescope pupil 6 ways before coupling light into fibers. An atmospheric dispersion corrector and fast tip-tilt system assures maximal light gathering within the 1.2″ entrance aperture. The six octagonal fibers corresponding to each slice of the pupil employ ball-lens double scramblers to stabilize the near-and far-fields. Three apiece are coupled into each of two rectangular fibers, to mitigate modal nose and present a rectilinear illumination pattern at the spectrograph's slit plane. Wavelength solutions are derived from ThAr lamps and an extremely wide coverage dual-channel laser frequency comb. Data is reduced on the fly for evaluation by a custom pipeline, while daily archives and extended scope data reduction products are stored on NExScI servers, also managing archives and access privileges for GTO and GO programs.Note: individual papers, submitted along this main paper, describe the details of subsystems such as the optical design (Barnes et al.,, the fiber link design (Fűrész et al.,, and the pupil slicer (Egan et al.,.

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“…The Transiting Exoplanet Survey Satellite (TESS) 3 and CHaracterising ExOPlanet Satellite (CHEOPS) 4 will launch in the 2017-2018 time frame and provide a large sample of bright, low mass transiting exoplanets extending over the whole sky. While the current and coming generation of instruments on 3.5 -10 m telescopes, especially ESPRESSO 5 , CARMENES 6 , EPDS 7 , SHREK 8 , EXPRES 9 and Maroon-X 10 , will open up new discovery space in the TESS and CHEOPS catalogues, many discoveries will only be possible with the 25.4 m aperture of the GMT, especially the search for the biomarker O 2 in exoplanet atmospheres 11,12 .…”

Section: Introductionmentioning

confidence: 99%

The GMT-Consortium Large Earth Finder (G-CLEF): an optical Echelle spectrograph for the Giant Magellan Telescope (GMT)

et al. 2016

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The GMT-Consortium Large Earth Finder (G-CLEF) will be a cross-dispersed, optical band echelle spectrograph to be delivered as the first light scientific instrument for the Giant Magellan Telescope (GMT) in 2022. G-CLEF is vacuumenclosed and fiber-fed to enable precision radial velocity (PRV) measurements, especially for the detection and characterization of low-mass exoplanets orbiting solar-type stars. The passband of G-CLEF is broad, extending from 3500Å to 9500Å. This passband provides good sensitivity at blue wavelengths for stellar abundance studies and deep red response for observations of high-redshift phenomena. The design of G-CLEF incorporates several novel technical innovations. We give an overview of the innovative features of the current design. G-CLEF will be the first PRV spectrograph to have a composite optical bench so as to exploit that material's extremely low coefficient of thermal expansion, high in-plane thermal conductivity and high stiffness-to-mass ratio. The spectrograph camera subsystem is divided into a red and a blue channel, split by a dichroic, so there are two independent refractive spectrograph cameras. The control system software is being developed in model-driven software context that has been adopted globally by the GMT. G-CLEF has been conceived and designed within a strict systems engineering framework. As a part of this process, we have developed a analytical toolset to assess the predicted performance of G-CLEF as it has evolved through design phases.

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EXPRES: a next generation RV spectrograph in the search for earth-like worlds

Cited by 133 publications

References 17 publications

Detection of neutral atomic species in the ultra-hot Jupiter WASP-121b

Detection of neutral atomic species in the ultra-hot Jupiter WASP-121b

WISDOM: the WIYN spectrograph for Doppler monitoring: a NASA-NSF concept for an extreme precision radial velocity instrument in support of TESS

The GMT-Consortium Large Earth Finder (G-CLEF): an optical Echelle spectrograph for the Giant Magellan Telescope (GMT)

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