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...

Full description

Bibliographic Details
Main Authors: 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
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