Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets
Mass, radius, and age measurements of young (≲100 Myr) planets have the power to shape our understanding of planet formation. However, young stars tend to be extremely variable in both photometry and radial velocity (RV) measurements, which makes constraining these properties challenging. The V1298...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
IOP Publishing
2023-01-01
|
Series: | The Astronomical Journal |
Subjects: | |
Online Access: | https://doi.org/10.3847/1538-3881/acde78 |
_version_ | 1827825653650554880 |
---|---|
author | Sarah Blunt Adolfo Carvalho Trevor J. David Charles Beichman Jon K. Zink Eric Gaidos Aida Behmard Luke G. Bouma Devin Cody Fei Dai Daniel Foreman-Mackey Sam Grunblatt Andrew W. Howard Molly Kosiarek Heather A. Knutson Ryan A. Rubenzahl Corey Beard Ashley Chontos Steven Giacalone Teruyuki Hirano Marshall C. Johnson Jack Lubin Joseph M. Akana Murphy Erik A Petigura Judah Van Zandt Lauren Weiss |
author_facet | Sarah Blunt Adolfo Carvalho Trevor J. David Charles Beichman Jon K. Zink Eric Gaidos Aida Behmard Luke G. Bouma Devin Cody Fei Dai Daniel Foreman-Mackey Sam Grunblatt Andrew W. Howard Molly Kosiarek Heather A. Knutson Ryan A. Rubenzahl Corey Beard Ashley Chontos Steven Giacalone Teruyuki Hirano Marshall C. Johnson Jack Lubin Joseph M. Akana Murphy Erik A Petigura Judah Van Zandt Lauren Weiss |
author_sort | Sarah Blunt |
collection | DOAJ |
description | Mass, radius, and age measurements of young (≲100 Myr) planets have the power to shape our understanding of planet formation. However, young stars tend to be extremely variable in both photometry and radial velocity (RV) measurements, which makes constraining these properties challenging. The V1298 Tau system of four ∼0.5 R _J planets transiting a pre-main-sequence star presents an important, if stress-inducing, opportunity to observe and measure directly the properties of infant planets. Suárez Mascareño et al. published radial-velocity-derived masses for two of the V1298 Tau planets using a state-of-the-art Gaussian process regression framework. The planetary densities computed from these masses were surprisingly high, implying extremely rapid contraction after formation in tension with most existing planet-formation theories. In an effort to constrain further the masses of the V1298 Tau planets, we obtained 36 RVs using Keck/HIRES, and analyzed them in concert with published RVs and photometry. Through performing a suite of cross-validation tests, we found evidence that the preferred model of Suárez Mascareño et al. suffers from overfitting, defined as the inability to predict unseen data, rendering the masses unreliable. We detail several potential causes of this overfitting, many of which may be important for other RV analyses of other active stars, and recommend that additional time and resources be allocated to understanding and mitigating activity in active young stars such as V1298 Tau. |
first_indexed | 2024-03-12T02:52:48Z |
format | Article |
id | doaj.art-040b54104b3e4975b3b7a45d6884ab10 |
institution | Directory Open Access Journal |
issn | 1538-3881 |
language | English |
last_indexed | 2024-03-12T02:52:48Z |
publishDate | 2023-01-01 |
publisher | IOP Publishing |
record_format | Article |
series | The Astronomical Journal |
spelling | doaj.art-040b54104b3e4975b3b7a45d6884ab102023-09-03T15:26:24ZengIOP PublishingThe Astronomical Journal1538-38812023-01-0116626210.3847/1538-3881/acde78Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau PlanetsSarah Blunt0https://orcid.org/0000-0002-3199-2888Adolfo Carvalho1https://orcid.org/0000-0002-9540-853XTrevor J. David2https://orcid.org/0000-0001-6534-6246Charles Beichman3https://orcid.org/0000-0002-5627-5471Jon K. Zink4https://orcid.org/0000-0003-1848-2063Eric Gaidos5https://orcid.org/0000-0002-5258-6846Aida Behmard6https://orcid.org/0000-0003-0012-9093Luke G. Bouma7https://orcid.org/0000-0002-0514-5538Devin Cody8https://orcid.org/0000-0002-7713-5937Fei Dai9https://orcid.org/0000-0002-8958-0683Daniel Foreman-Mackey10https://orcid.org/0000-0002-9328-5652Sam Grunblatt11https://orcid.org/0000-0003-4976-9980Andrew W. Howard12https://orcid.org/0000-0001-8638-0320Molly Kosiarek13https://orcid.org/0000-0002-6115-4359Heather A. Knutson14https://orcid.org/0000-0002-5375-4725Ryan A. Rubenzahl15https://orcid.org/0000-0003-3856-3143Corey Beard16https://orcid.org/0000-0001-7708-2364Ashley Chontos17https://orcid.org/0000-0003-1125-2564Steven Giacalone18https://orcid.org/0000-0002-8965-3969Teruyuki Hirano19https://orcid.org/0000-0003-3618-7535Marshall C. Johnson20https://orcid.org/0000-0002-5099-8185Jack Lubin21https://orcid.org/0000-0001-8342-7736Joseph M. Akana Murphy22https://orcid.org/0000-0001-8898-8284Erik A Petigura23https://orcid.org/0000-0003-0967-2893Judah Van Zandt24https://orcid.org/0000-0002-4290-6826Lauren Weiss25https://orcid.org/0000-0002-3725-3058Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; sblunt@astro.caltech.eduDepartment of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; sblunt@astro.caltech.eduCenter for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USANASA Jet Propulsion Laboratory: Pasadena , CA, USADepartment of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; sblunt@astro.caltech.eduDepartment of Earth Sciences, University of Hawai’i at Mānoa , Honolulu, HI 96822 USADivision of Geological and Planetary Sciences , 1200 E California Boulevard, Pasadena, CA 91125, USADepartment of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; sblunt@astro.caltech.eduGoogle LLC , 1600 Amphitheater Parkway, Mountain View, CA 94043, USADepartment of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; sblunt@astro.caltech.edu; Division of Geological and Planetary Sciences , 1200 E California Boulevard, Pasadena, CA 91125, USACenter for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USACenter for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USA; American Museum of Natural History , 200 Central Park West, Manhattan, NY 10024, USA; Department of Physics and Astronomy, Johns Hopkins University , 3400 N Charles Street, Baltimore, MD 21218, USADepartment of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; sblunt@astro.caltech.eduDepartment of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USADivision of Geological and Planetary Sciences , 1200 E California Boulevard, Pasadena, CA 91125, USADepartment of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; sblunt@astro.caltech.eduDepartment of Physics & Astronomy, The University of California, Irvine , Irvine, CA 92697, USADepartment of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08540, USADepartment of Astronomy, University of California Berkeley , Berkeley, CA 94720, USAAstrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, JapanDepartment of Astronomy, The Ohio State University , 4055 McPherson Laboratory, 140 West 18th Avenue, Columbus, OH 43210 USADepartment of Physics & Astronomy, The University of California, Irvine , Irvine, CA 92697, USADepartment of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USADepartment of Physics & Astronomy, University of California Los Angeles , Los Angeles, CA 90095, USADepartment of Physics & Astronomy, University of California Los Angeles , Los Angeles, CA 90095, USADepartment of Physics and Astronomy, University of Notre Dame , Notre Dame, IN 46556, USAMass, radius, and age measurements of young (≲100 Myr) planets have the power to shape our understanding of planet formation. However, young stars tend to be extremely variable in both photometry and radial velocity (RV) measurements, which makes constraining these properties challenging. The V1298 Tau system of four ∼0.5 R _J planets transiting a pre-main-sequence star presents an important, if stress-inducing, opportunity to observe and measure directly the properties of infant planets. Suárez Mascareño et al. published radial-velocity-derived masses for two of the V1298 Tau planets using a state-of-the-art Gaussian process regression framework. The planetary densities computed from these masses were surprisingly high, implying extremely rapid contraction after formation in tension with most existing planet-formation theories. In an effort to constrain further the masses of the V1298 Tau planets, we obtained 36 RVs using Keck/HIRES, and analyzed them in concert with published RVs and photometry. Through performing a suite of cross-validation tests, we found evidence that the preferred model of Suárez Mascareño et al. suffers from overfitting, defined as the inability to predict unseen data, rendering the masses unreliable. We detail several potential causes of this overfitting, many of which may be important for other RV analyses of other active stars, and recommend that additional time and resources be allocated to understanding and mitigating activity in active young stars such as V1298 Tau.https://doi.org/10.3847/1538-3881/acde78StarspotsRadial velocity |
spellingShingle | Sarah Blunt Adolfo Carvalho Trevor J. David Charles Beichman Jon K. Zink Eric Gaidos Aida Behmard Luke G. Bouma Devin Cody Fei Dai Daniel Foreman-Mackey Sam Grunblatt Andrew W. Howard Molly Kosiarek Heather A. Knutson Ryan A. Rubenzahl Corey Beard Ashley Chontos Steven Giacalone Teruyuki Hirano Marshall C. Johnson Jack Lubin Joseph M. Akana Murphy Erik A Petigura Judah Van Zandt Lauren Weiss Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets The Astronomical Journal Starspots Radial velocity |
title | Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets |
title_full | Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets |
title_fullStr | Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets |
title_full_unstemmed | Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets |
title_short | Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets |
title_sort | overfitting affects the reliability of radial velocity mass estimates of the v1298 tau planets |
topic | Starspots Radial velocity |
url | https://doi.org/10.3847/1538-3881/acde78 |
work_keys_str_mv | AT sarahblunt overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT adolfocarvalho overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT trevorjdavid overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT charlesbeichman overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT jonkzink overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT ericgaidos overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT aidabehmard overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT lukegbouma overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT devincody overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT feidai overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT danielforemanmackey overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT samgrunblatt overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT andrewwhoward overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT mollykosiarek overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT heatheraknutson overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT ryanarubenzahl overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT coreybeard overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT ashleychontos overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT stevengiacalone overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT teruyukihirano overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT marshallcjohnson overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT jacklubin overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT josephmakanamurphy overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT erikapetigura overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT judahvanzandt overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets AT laurenweiss overfittingaffectsthereliabilityofradialvelocitymassestimatesofthev1298tauplanets |