Near-InfraRed Planet Searcher to Join HARPS on the ESO 3.6-metre Telescope

Bouchy, F.; Doyon, René; Artigau, Étienne; Melo, C.; Hernandez, O.; Wildi, F.; Delfosse, X.; Lovis, C.; Figueira, P.; Martins, B. L. Canto; Hernández, J. I. González; Thibault, Simon; Решетов, В. А.; Pepe, F.; Santos, N. C.; Medeiros, J. R. De; Реболо, Р.; Abreu, Manuel; Adibekyan, V.; Bandy, T.; Benz, W.; Blind, N.; Bohlender, D.; Boisse, I.; Bovay, S.; Broeg, C.; Brousseau, Denis; Cabral, Alexandre; Chazelas, Bruno; Cloutier, Ryan; Coelho, João M. P.; Conod, U.; Cumming, Andrew; Délabre, B.; Genolet, L.; Hagelberg, J.; Jayawardhana, Ray; Käufl, H. U.; Lafrenière, David; Leão, I. C.; Malo, Lison; Martins, A. . de Medeiros; Matthews, J. M.; Metchev, Stanimir; Oshagh, M.; Ouellet, Mathieu; Parro, Vanderlei Cunha; Piñeiro, J.; Santos, P.; Sarajlic, M.; Segovia, A.; Sordet, M.; Udry, S.; Valencia, Diana; Vallée, P.; Venn, Kim A.; Wade, G. A.; Saddlemyer, Les

doi:10.18727/0722-6691/5034

Cited by 25 publications

(11 citation statements)

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“…Finally, near-infrared spectroscopic observations of Proxima Cen with upcoming instruments like NIRPS (Bouchy et al 2017;Wildi et al 2017) will complement the analysis by allowing the measurement of other activity indicators (e.g., based on the emission flux in the core of the He I triplet at 1083 nm, and Paschen 𝛽), and by constraining the ratio <𝐵 I >/<𝐵 V > thanks to the larger Zeeman broadening in the near-infrared than in the optical domain.…”

Section: Magnetic Activity and Cycle Of Proxima Cenmentioning

confidence: 99%

The large-scale magnetic field of Proxima Centauri near activity maximum

Klein,

Donati,

Hébrard

et al. 2020

Preprint

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We report the detection of a large-scale magnetic field at the surface of the slowly-rotating fully-convective M dwarf Proxima Centauri. Ten circular polarization spectra, collected from April to July 2017 with the HARPS-Pol spectropolarimeter, exhibit rotationally-modulated Zeeman signatures suggesting a stellar rotation period of 89.8 ± 4.0 d. Using Zeeman-Doppler Imaging, we invert the circular polarization spectra into a surface distribution of the largescale magnetic field. We find that Proxima Cen hosts a large-scale magnetic field of typical strength 200 G, whose topology is mainly poloidal, and moderately axisymmetric, featuring, in particular, a dipole component of 135 G tilted at 51 • to the rotation axis. The large-scale magnetic flux is roughly 3× smaller than the flux measured from the Zeeman broadening of unpolarized lines, which suggests that the underlying dynamo is efficient at generating a magnetic field at the largest spatial scales. Our observations occur ∼1 yr after the maximum of the reported 7 yr-activity cycle of Proxima Cen, which opens the door for the first long-term study of how the large-scale field evolves with the magnetic cycle in a fully-convective verylow-mass star. Finally, we find that Proxima Cen's habitable zone planet, Proxima-b, is likely orbiting outside the Alfvèn surface, where no direct magnetic star-planet interactions occur.

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Section: Magnetic Activity and Cycle Of Proxima Cenmentioning

confidence: 99%

The large-scale magnetic field of Proxima Centauri near activity maximum

Klein,

Donati,

Hébrard

et al. 2020

Preprint

Self Cite

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“…An increasing number of EPRV instruments are coming online and returning sub-meter-per-second singlemeasurement precision (e.g., Pepe et al 2013;Jurgenson et al 2016;Schwab et al 2016;Carmona et al 2018;Seifahrt et al 2018;Gilbert et al 2018;Blackman et al 2020;Petersburg et al 2020;Suárez Mascareño et al 2020;Pepe et al 2021) with many more optical and infrared spectrographs being commissioned, built, or planned (e.g., Szentgyorgyi et al 2014;Thompson et al 2016;Bouchy et al 2017;Gibson et al 2018). The impressive engineering feat of these different instruments is opening up a new regime of extremely stable and precise spectroscopic data.…”

Section: Discussionmentioning

confidence: 99%

The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities

Zhao,

Fischer,

Ford

et al. 2022

Preprint

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Measured spectral shifts due to intrinsic stellar variability (e.g., pulsations, granulation) and activity (e.g., spots, plages) are the largest source of error for extreme precision radial velocity (EPRV) exoplanet detection. Several methods are designed to disentangle stellar signals from true center-of-mass shifts due to planets. The EXPRES Stellar Signals Project (ESSP) presents a self-consistent comparison of 22 different methods tested on the same extreme-precision spectroscopic data from EXPRES. Methods derived new activity indicators, constructed models for mapping an indicator to the needed RV correction, or separated out shape-and shift-driven RV components. Since no ground truth is known when using real data, relative method performance is assessed using the total and nightly scatter of returned RVs and agreement between the results of different methods. Nearly all submitted methods return a lower RV RMS than classic linear decorrelation, but no method is yet consistently reducing the RV RMS to sub-meter-per-second levels. There is a concerning lack of agreement between the RVs returned by different methods. These results suggest that continued progress in this field necessitates increased interpretability of methods, high-cadence data to capture stellar signals at all timescales, and continued tests like the ESSP using consistent data sets with more advanced metrics for method performance. Future comparisons should make use of various well-characterized data sets-such as solar data or data with known injected planetary and/or stellar signals-to better understand method performance and whether planetary signals are preserved.

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“…The NIR instruments (NIRCam or NIRSpec) on the forthcoming JWST will be able to leverage on this to detect oblateness with greater ease. Spectrographs operating in NIR such as NIRPS (Bouchy et al 2017), CARMENES (Quirrenbach et al 2016), andSPIRou (Donati et al 2018) can also be beneficial although, as they are installed on 4m class telescopes, they cannot achieve RV precisions as high as ESPRESSO.…”

Section: Discussionmentioning

confidence: 99%

Constraining the oblateness of transiting planets with photometry and spectroscopy

Akinsanmi,

Barros,

Santos

et al. 2020

Preprint

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Rapid planetary rotation can cause the equilibrium shape of a planet to be oblate. While planetary oblateness has mostly been probed by examining the subtle ingress and egress features in photometric transit light curves, we investigate the effect of oblateness on the spectroscopic Rossiter-McLaughlin (RM) signals. We found that a giant planet, with planet-to-star radius ratio of 0.15 and Saturn-like oblateness of 0.098, can cause spectroscopic signatures with amplitudes up to 1.1 m s −1 which is detectable by high-precision spectrographs such as ESPRESSO. We also found that the spectroscopic oblateness signals are particularly amplified for transits across rapidly rotating stars and for planets with spin-orbit misalignment thereby making them more prominent than the photometric signals at some transit orientations. We compared the detectability of oblateness in photometry and spectroscopy and found that photometric light curves are more sensitive to detecting oblateness than the spectroscopic RM signals mostly because they can be sampled with higher cadence to better probe the oblateness ingress and egress anomaly. However, joint analyses of the light curve and RM signal of a transiting planet provides more accurate and precise estimate of the planet's oblateness. Therefore, ESPRESSO alongside ongoing and upcoming photometric instruments such as TESS, CHEOPS, PLATO and JWST will be extremely useful in measuring planet oblateness.

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Near-InfraRed Planet Searcher to Join HARPS on the ESO 3.6-metre Telescope

Cited by 25 publications

References 0 publications

The large-scale magnetic field of Proxima Centauri near activity maximum

The large-scale magnetic field of Proxima Centauri near activity maximum

The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities

Constraining the oblateness of transiting planets with photometry and spectroscopy

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