TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet

Osborn, Ares; Armstrong, David J; Cale, Bryson; Brahm, Rafael; Wittenmyer, Robert A; Dai, Fei; Crossfield, Ian J M; Bryant, Edward M; Adibekyan, Vardan; Cloutier, Ryan; Collins, Karen A; Mena, E Delgado; Fridlund, Malcolm; Hellier, Coel; Howell, Steve B; King, George W; Lillo-Box, Jorge; Otegi, Jon; Sousa, S; Stassun, Keivan G; Matthews, Elisabeth C; Ziegler, Carl; Ricker, George; Vanderspek, Roland; Latham, David W; Seager, S; Winn, Joshua N; Jenkins, Jon M; Acton, Jack S; Addison, Brett C; Anderson, David R; Ballard, Sarah; Barrado, David; Barros, Susana C C; Batalha, Natalie; Bayliss, Daniel; Barclay, Thomas; Benneke, Björn; Berberian Jr., John; Bouchy, Francois; Bowler, Brendan P; Briceño, César; Burke, Christopher J; Burleigh, Matthew R; Casewell, Sarah L; Ciardi, David; Collins, Kevin I; Cooke, Benjamin F; Demangeon, Olivier D S; Díaz, Rodrigo F; Dorn, C; Dragomir, Diana; Dressing, Courtney; Dumusque, Xavier; Espinoza, Néstor; Figueira, P; Fulton, Benjamin; Furlan, E; Gaidos, E; Geneser, C; Gill, Samuel; Goad, Michael R; Gonzales, Erica J; Gorjian, Varoujan; Günther, Maximilian N; Helled, Ravit; Henderson, Beth A; Henning, Thomas; Hogan, Aleisha; Hojjatpanah, Saeed; Horner, Jonathan; Howard, Andrew W; Hoyer, Sergio; Huber, Dan; Isaacson, Howard; Jenkins, James S; Jensen, Eric L N; Jordán, Andrés; Kane, Stephen R; Kidwell Jr., Richard C; Kielkopf, John; Law, Nicholas; Lendl, Monika; Lund, M; Matson, Rachel A; Mann, Andrew W; McCormac, James; Mengel, Matthew W; Morales, Farisa Y; Nielsen, Louise D; Okumura, Jack; Osborn, Hugh P; Petigura, Erik A; Plavchan, Peter; Pollacco, Don; Quintana, Elisa V; Raynard, Liam; Robertson, Paul; Rose, Mark E; Roy, Arpita; Reefe, Michael; Santerne, Alexandre; Santos, Nuno C; Sarkis, Paula; Schlieder, J; Schwarz, Richard P; Scott, Nicholas J; Shporer, Avi; Smith, A M S; Stibbard, C; Stockdale, Chris; Strøm, Paul A; Twicken, Joseph D; Tan, Thiam-Guan; Tanner, A; Teske, J; Tilbrook, Rosanna H; Tinney, C G; Udry, Stephane; Noel Villaseñor, Jesus; Vines, Jose I; Wang, Sharon X; Weiss, Lauren M; West, Richard G; Wheatley, Peter J; Wright, Duncan J; Zhang, Hui; Zohrabi, F

doi:10.1093/mnras/stab2313

TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet

Osborn, Ares; Armstrong, David J; Cale, Bryson; Brahm, Rafael; Wittenmyer, Robert A; Dai, Fei; Crossfield, Ian J M; Bryant, Edward M; Adibekyan, Vardan; Cloutier, Ryan; Collins, Karen A; Mena, E Delgado; Fridlund, Malcolm; Hellier, Coel; Howell, Steve B; King, George W; Lillo-Box, Jorge; Otegi, Jon; Sousa, S; Stassun, Keivan G; Matthews, Elisabeth C; Ziegler, Carl; Ricker, George; Vanderspek, Roland; Latham, David W; Seager, S; Winn, Joshua N; Jenkins, Jon M; Acton, Jack S; Addison, Brett C; Anderson, David R; Ballard, Sarah; Barrado, David; Barros, Susana C C; Batalha, Natalie; Bayliss, Daniel; Barclay, Thomas; Benneke, Björn; Berberian Jr., John; Bouchy, Francois; Bowler, Brendan P; Briceño, César; Burke, Christopher J; Burleigh, Matthew R; Casewell, Sarah L; Ciardi, David; Collins, Kevin I; Cooke, Benjamin F; Demangeon, Olivier D S; Díaz, Rodrigo F; Dorn, C; Dragomir, Diana; Dressing, Courtney; Dumusque, Xavier; Espinoza, Néstor; Figueira, P; Fulton, Benjamin; Furlan, E; Gaidos, E;...

Authors

Ares Osborn

David J Armstrong

Bryson Cale

Rafael Brahm

Robert A Wittenmyer

Fei Dai

Ian J M Crossfield

Edward M Bryant

Vardan Adibekyan

Ryan Cloutier

Karen A Collins

E Delgado Mena

Malcolm Fridlund

Coel Hellier c.hellier@keele.ac.uk

Steve B Howell

George W King

Jorge Lillo-Box

Jon Otegi

S Sousa

Keivan G Stassun

Elisabeth C Matthews

Carl Ziegler

George Ricker

Roland Vanderspek

David W Latham

S Seager

Joshua N Winn

Jon M Jenkins

Jack S Acton

Brett C Addison

David R Anderson

Sarah Ballard

David Barrado

Susana C C Barros

Natalie Batalha

Daniel Bayliss

Thomas Barclay

Björn Benneke

John Berberian Jr.

Francois Bouchy

Brendan P Bowler

César Briceño

Christopher J Burke

Matthew R Burleigh

Sarah L Casewell

David Ciardi

Kevin I Collins

Benjamin F Cooke

Olivier D S Demangeon

Rodrigo F Díaz

C Dorn

Diana Dragomir

Courtney Dressing

Xavier Dumusque

Néstor Espinoza

P Figueira

Benjamin Fulton

E Furlan

E Gaidos

C Geneser

Samuel Gill

Michael R Goad

Erica J Gonzales

Varoujan Gorjian

Maximilian N Günther

Ravit Helled

Beth A Henderson

Thomas Henning

Aleisha Hogan

Saeed Hojjatpanah

Jonathan Horner

Andrew W Howard

Sergio Hoyer

Dan Huber

Howard Isaacson

James S Jenkins

Eric L N Jensen

Andrés Jordán

Stephen R Kane

Richard C Kidwell Jr.

John Kielkopf

Nicholas Law

Monika Lendl

M Lund

Rachel A Matson

Andrew W Mann

James McCormac

Matthew W Mengel

Farisa Y Morales

Louise D Nielsen

Jack Okumura

Hugh P Osborn

Erik A Petigura

Peter Plavchan

Don Pollacco

Elisa V Quintana

Liam Raynard

Paul Robertson

Mark E Rose

Arpita Roy

Michael Reefe

Alexandre Santerne

Nuno C Santos

Paula Sarkis

J Schlieder

Richard P Schwarz

Nicholas J Scott

Avi Shporer

A M S Smith

C Stibbard

Chris Stockdale

Paul A Strøm

Joseph D Twicken

Thiam-Guan Tan

A Tanner

J Teske

Rosanna H Tilbrook

C G Tinney

Stephane Udry

Jesus Noel Villaseñor

Jose I Vines

Sharon X Wang

Lauren M Weiss

Richard G West

Peter J Wheatley

Duncan J Wright

Hui Zhang

F Zohrabi

Abstract

We present the bright (Vmag = 9.12), multiplanet system TOI-431, characterized with photometry and radial velocities (RVs). We estimate the stellar rotation period to be 30.5 ± 0.7 d using archival photometry and RVs. Transiting Exoplanet Survey Satellite (TESS) objects of Interest (TOI)-431?b is a super-Earth with a period of 0.49 d, a radius of 1.28 ± 0.04 R?, a mass of 3.07 ± 0.35 M?, and a density of 8.0 ± 1.0 g cm-3; TOI-431 d is a sub-Neptune with a period of 12.46 d, a radius of 3.29 ± 0.09 R?, a mass of 9.90+1.53-1.49 M?, and a density of 1.36 ± 0.25 g cm-3. We find a third planet, TOI-431?c, in the High Accuracy Radial velocity Planet Searcher RV data, but it is not seen to transit in the TESS light curves. It has an Msin i of 2.83+0.41-0.34 M?, and a period of 4.85 d. TOI-431?d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterization, while the super-Earth TOI-431?b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431?b is a prime TESS discovery for the study of rocky planet phase curves.

Citation

Osborn, A., Armstrong, D. J., Cale, B., Brahm, R., Wittenmyer, R. A., Dai, F., …Zohrabi, F. (2021). TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet. Monthly Notices of the Royal Astronomical Society, 507(2), 2782 - 2803. https://doi.org/10.1093/mnras/stab2313

Journal Article Type	Article
Acceptance Date	Aug 3, 2021
Online Publication Date	Aug 11, 2021
Publication Date	2021-10
Publicly Available Date	May 30, 2023
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Publisher	Oxford University Press
Peer Reviewed	Peer Reviewed
Volume	507
Issue	2
Pages	2782 - 2803
DOI	https://doi.org/10.1093/mnras/stab2313
Keywords	Space and Planetary Science, Astronomy and Astrophysics
Publisher URL	https://academic.oup.com/mnras/article-abstract/507/2/2782/6348103?redirectedFrom=fulltext