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dc.contributor.authorMilbourne, TW
dc.contributor.authorPhillips, DF
dc.contributor.authorLangellier, N
dc.contributor.authorMortier, A
dc.contributor.authorHaywood, RD
dc.contributor.authorSaar, SH
dc.contributor.authorCegla, HM
dc.contributor.authorCameron, AC
dc.contributor.authorDumusque, X
dc.contributor.authorLatham, DW
dc.contributor.authorMalavolta, L
dc.contributor.authorMaldonado, J
dc.contributor.authorThompson, S
dc.contributor.authorVanderburg, A
dc.contributor.authorWatson, CA
dc.contributor.authorBuchhave, LA
dc.contributor.authorCecconi, M
dc.contributor.authorCosentino, R
dc.contributor.authorGhedina, A
dc.contributor.authorGonzalez, M
dc.contributor.authorLodi, M
dc.contributor.authorLopez-Morales, M
dc.contributor.authorSozzetti, A
dc.contributor.authorWalsworth, RL
dc.identifier.citationMilbourne , TW , Phillips , DF , Langellier , N , Mortier , A , Haywood , RD , Saar , SH , Cegla , HM , Cameron , AC , Dumusque , X , Latham , DW , Malavolta , L , Maldonado , J , Thompson , S , Vanderburg , A , Watson , CA , Buchhave , LA , Cecconi , M , Cosentino , R , Ghedina , A , Gonzalez , M , Lodi , M , Lopez-Morales , M , Sozzetti , A & Walsworth , RL 2021 , ' Estimating magnetic filling factors from simultaneous spectroscopy and photometry : disentangling spots, plage, and network ' , Astrophysical Journal , vol. 920 , no. 1 , 21 .
dc.identifier.otherPURE: 276371054
dc.identifier.otherPURE UUID: 0e656ce6-7a65-4649-b6b0-90f15a94bbd5
dc.identifier.otherRIS: urn:D4EA5059FA729CDC587824A0D052F7B2
dc.identifier.otherWOS: 000704879900001
dc.identifier.otherORCID: /0000-0002-8863-7828/work/101958343
dc.identifier.otherScopus: 85117158103
dc.descriptionA.C.C. acknowledges support from the Science and Technology Facilities Council (STFC) consolidated grant number ST/R000824/1.en
dc.description.abstractState-of-the-art radial velocity (RV) exoplanet searches are limited by the effects of stellar magnetic activity. Magnetically active spots, plage, and network regions each have different impacts on the observed spectral lines and therefore on the apparent stellar RV. Differentiating the relative coverage, or filling factors, of these active regions is thus necessary to differentiate between activity-driven RV signatures and Doppler shifts due to planetary orbits. In this work, we develop a technique to estimate feature-specific magnetic filling factors on stellar targets using only spectroscopic and photometric observations. We demonstrate linear and neural network implementations of our technique using observations from the solar telescope at HARPS-N, the HK Project at the Mt. Wilson Observatory, and the Total Irradiance Monitor onboard SORCE. We then compare the results of each technique to direct observations by the Solar Dynamics Observatory. Both implementations yield filling factor estimates that are highly correlated with the observed values. Modeling the solar RVs using these filling factors reproduces the expected contributions of the suppression of convective blueshift and rotational imbalance due to brightness inhomogeneities. Both implementations of this technique reduce the overall activity-driven rms RVs from 1.64 to 1.02 m s(-1), corresponding to a 1.28 m s(-1) reduction in the rms variation. The technique provides an additional 0.41 m s(-1) reduction in the rms variation compared to traditional activity indicators.
dc.relation.ispartofAstrophysical Journalen
dc.rightsCopyright © 2021 The American Astronomical Society. All rights reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at
dc.subjectSolar activityen
dc.subjectRadial velocityen
dc.subjectExoplanet detection methodsen
dc.subjectSolar active regionsen
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.titleEstimating magnetic filling factors from simultaneous spectroscopy and photometry : disentangling spots, plage, and networken
dc.typeJournal articleen
dc.contributor.institutionUniversity of St Andrews.School of Physics and Astronomyen
dc.contributor.institutionUniversity of St Andrews.St Andrews Centre for Exoplanet Scienceen
dc.description.statusPeer revieweden

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