Performance Verification of the EXtreme PREcision Spectrograph

Blackman, Ryan; Fischer, Debra A.; Jurgenson, C. A.; Sawyer, David; McCracken, Tyler; Szymkowiak, Andrew E.; Petersburg, Ryan R.; Ong, J. M. Joel; Brewer, John M.; Zhao, Lily; Leet, Christopher; Buchhave, Lars A.; Tronsgaard, R.; Llama, Joe; Sawyer, Travis W.; Davis, Allen B.; Cabot, Samuel H. C.; Shao, Michael; Trahan, Russell; Nemati, Bijan; Genoni, Matteo; Pariani, Giorgio; Riva, M.; Fournier, P.; Pawluczyk, Rafal

doi:10.3847/1538-3881/ab811d

Cited by 59 publications

(45 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Radial velocity instrument stability and calibration is rapidly approaching the ability to detect an Earth-like signal. For example, the NEID spectrograph has an error budget of 27 cm s −1 (Halverson et al 2016), the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) is achieving a 28 cm s −1 dispersion on sky over a single night (Pepe et al 2014), and laser frequency comb measurements on EXtreme PREcision Spectrometer (EXPRES) are showing an instrumental precision of <10 cm s −1 (Zhao & The EXPRES Team 2019; Blackman et al 2020;Petersburg et al 2020). Yet there is much work needed to mitigate stellar activity to detect such a small signal on sky.…”

Section: Introductionmentioning

confidence: 99%

Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses

Kosiarek

Crossfield

2020

View full text Add to dashboard Cite

Stellar activity remains a limiting factor in measuring precise planet parameters from radial velocity spectroscopy, not least in the search for Earth-mass planets orbiting in the habitable zones of Sun-like stars. One approach to mitigate stellar activity is to use combined analyses of both radial velocity and time-series photometry. We present an analysis of simultaneous disk-integrated photometry and radial velocity data of the Sun in order to determine the useful limits of a combined analysis. We find that simple periodogram or autocorrelation analysis of solar photometry give the correct rotation period <50% of the time. We therefore use a Gaussian process to investigate the time variability of solar photometry and to directly compare simultaneous photometry with radial velocity data. We find that the hyperparameter posteriors are relatively stable over 70 yr of solar photometry and the amplitude tracks the solar cycle. We observe good agreement between the hyperparameter posteriors for the simultaneous photometry and radial velocity data. Our primary conclusion is a recommendation to include an additional prior in Gaussian process fits to constrain the evolutionary timescale to be greater than the recurrence timescale (i.e., the rotation period) to recover more physically plausible and useful results. Our results indicate that such simultaneous monitoring may be a useful tool in enhancing the precision of radial velocity surveys.

show abstract

Section: Introductionmentioning

confidence: 99%

Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses

Kosiarek

Crossfield

2020

View full text Add to dashboard Cite

show abstract

“…Successful exo-Earth discovery therefore requires both more sophisticated models of stellar variability and the improved RV precision, long-term stability, and dense observational sampling from a next-generation spectrograph (Wright & Robertson 2017) such as the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO; Pepe et al 2013Pepe et al , 2021Damasso et al 2020;Suárez Mascareño et al 2020), NEID (Allen et al 2018), EXtreme PREcision Spectrometer (EXPRES; Jurgenson et al 2016;Blackman et al 2020;Brewer et al 2020;Petersburg et al 2020), HARPS3 (Thompson et al 2016), or GMT Consortium Large Earth Finder (G-CLEF; Szentgyorgyi et al 2014).…”

Section: Discussionmentioning

confidence: 99%

Detection Limits of Low-mass, Long-period Exoplanets Using Gaussian Processes Applied to HARPS-N Solar Radial Velocities

Langellier

Milbourne

Phillips

et al. 2021

View full text Add to dashboard Cite

Radial velocity (RV) searches for Earth-mass exoplanets in the habitable zone around Sun-like stars are limited by the effects of stellar variability on the host star. In particular, suppression of convective blueshift and brightness inhomogeneities due to photospheric faculae/plage and starspots are the dominant contribution to the variability of such stellar RVs. Gaussian process (GP) regression is a powerful tool for statistically modeling these quasi-periodic variations. We investigate the limits of this technique using 800 days of RVs from the solar telescope on the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) spectrograph. These data provide a well-sampled time series of stellar RV variations. Into this data set, we inject Keplerian signals with periods between 100 and 500 days and amplitudes between 0.6 and 2.4 m s −1 . We use GP regression to fit the resulting RVs and determine the statistical significance of recovered periods and amplitudes. We then generate synthetic RVs with the same covariance properties as the solar data to determine a lower bound on the observational baseline necessary to detect low-mass planets in Venus-like orbits around a Sun-like star. Our simulations show that discovering planets with a larger mass (∼0.5 m s −1 ) using current-generation spectrographs and GP regression will require more than 12 yr of densely sampled RV observations. Furthermore, even with a perfect model of stellar variability, discovering a true exo-Venus (∼0.1 m s −1 ) with current instruments would take over 15 yr. Therefore, next-generation spectrographs and better models of stellar variability are required for detection of such planets.

show abstract

“…EXPRES is an ultra-stable optical spectrograph recently commissioned at the Lowell Discovery Telescope (Levine et al 2012). It is designed for extreme-precision RV surveys (see Jurgenson et al 2016;Blackman et al 2020;Brewer et al 2020;Petersburg et al 2020, for details about the instrument specifications and reduction pipeline) and also has the capacity for atmospheric characterization (see, for example, the recent study of ultra-hot Jupiter MASCARA-2b by Hoeijmakers et al 2020). One transit of TOI-1518b was observed on the night of 2020 August 2, involving 41 ∼300 s exposures.…”

Section: Expres Spectroscopymentioning

confidence: 99%