The JWST Sub-Jupiters Survey: Direct-imaging Discovery of a Giant Planet and a Debris Disk around the Young M Dwarf RX J0534.0-0221

@article{ferrerchavez2026jwst,
  title = {{The JWST Sub-Jupiters Survey: Direct-imaging Discovery of a Giant Planet and a Debris Disk around the Young M Dwarf RX J0534.0-0221}},
  author = {Rodrigo Ferrer-Chavez and Jason J. Wang and Kevin Wagner and Kellen Lawson and Aarynn L. Carter and Beth Biller and Raphaël Bendahan-West and Patrick McCreery and Patricia Luppe and Steve Ertel and Andrew D. James and Ellis Bogat and Rohan Kane and Ben J. Sutlieff and Giovanni M. Strampelli and William O. Balmer and Rachel Bowens-Rubin and Evelyn L. Bruinsma and Andy Skemer and Julien H. Girard and Mark Booth and Klaus Subbotina Stephenson and Katie A. Crotts and Sebastian Marino and Aniket Sanghi and Michael Liu and Nour Skaf and Emily Rickman and Marshall D. Perrin and Laurent Pueyo and Brendan P. Bowler and James Mang and Isabel Rebollido and Michael Meyer and Tim Pearce and Markus Bonse and Clémence Fontanive and Jared Carlson and Jon Rees and Justin Rupert and Gabriel Weible and Jacob Isbell and Juan Carlos Guerra and Xueqing Chen and Mia Belle Parkinson and Vito Squicciarini and Gael Chauvin and Elisabeth Matthews and Kyle Franson and Maxwell A. Millar-Blanchaer and Sasha Hinkley},
  journal = {The Astrophysical Journal Letters},
  year = {2026},
  month = oct,
  doi = {10.3847/2041-8213/aea906},
  url = {https://iopscience.iop.org/article/10.3847/2041-8213/aea906},
  note = {CC BY 4.0},
}

TY  - JOUR
TI  - The JWST Sub-Jupiters Survey: Direct-imaging Discovery of a Giant Planet and a Debris Disk around the Young M Dwarf RX J0534.0-0221
AU  - Rodrigo Ferrer-Chavez
AU  - Jason J. Wang
AU  - Kevin Wagner
AU  - Kellen Lawson
AU  - Aarynn L. Carter
AU  - Beth Biller
AU  - Raphaël Bendahan-West
AU  - Patrick McCreery
AU  - Patricia Luppe
AU  - Steve Ertel
AU  - Andrew D. James
AU  - Ellis Bogat
AU  - Rohan Kane
AU  - Ben J. Sutlieff
AU  - Giovanni M. Strampelli
AU  - William O. Balmer
AU  - Rachel Bowens-Rubin
AU  - Evelyn L. Bruinsma
AU  - Andy Skemer
AU  - Julien H. Girard
AU  - Mark Booth
AU  - Klaus Subbotina Stephenson
AU  - Katie A. Crotts
AU  - Sebastian Marino
AU  - Aniket Sanghi
AU  - Michael Liu
AU  - Nour Skaf
AU  - Emily Rickman
AU  - Marshall D. Perrin
AU  - Laurent Pueyo
AU  - Brendan P. Bowler
AU  - James Mang
AU  - Isabel Rebollido
AU  - Michael Meyer
AU  - Tim Pearce
AU  - Markus Bonse
AU  - Clémence Fontanive
AU  - Jared Carlson
AU  - Jon Rees
AU  - Justin Rupert
AU  - Gabriel Weible
AU  - Jacob Isbell
AU  - Juan Carlos Guerra
AU  - Xueqing Chen
AU  - Mia Belle Parkinson
AU  - Vito Squicciarini
AU  - Gael Chauvin
AU  - Elisabeth Matthews
AU  - Kyle Franson
AU  - Maxwell A. Millar-Blanchaer
AU  - Sasha Hinkley
PY  - 2026
DA  - 2026/10/09
JO  - The Astrophysical Journal Letters
DO  - 10.3847/2041-8213/aea906
UR  - https://iopscience.iop.org/article/10.3847/2041-8213/aea906
AB  - We present the discovery of RX J0534.0-0221 b, a giant planet orbiting an M dwarf star in the β Pictoris moving group. RX J0534 was originally observed with JWST/NIRCam in the F444W and F200W filters. Observations in F444W reveal a point source at signal-to-noise ratio ∼17.5 at ∼ 0 . ″ 41 (∼14 au) from the host star, with no detection of the source in F200W. A follow-up observation with LBTI/LMIRCam in the L ′ band redetects the source 16 months after the JWST epoch, providing evidence for common proper motion over a chance alignment with a background interloper at the 6 σ –7 σ level. Atmospheric grid model fits to the available photometry yield the bolometric luminosity log 10 ( L / L ⊙ ) = − 5.4 8 − 0.19 + 0.10 dex. At an age of 18–26 Myr, hot-start evolutionary models predict M = 2 . 8 − 0.5 + 0.5 M Jup and T eff = 67 4 − 49 + 57 K. From the L ′ − F 444 W color and magnitudes, we find evidence for disequilibrium chemistry or enhanced metallicity in the planet's atmosphere. Additionally, an extended structure is detected in the JWST F200W observation, consistent with a resolved debris disk with a peak density radius of 7 9 − 3 + 3 au and an inclination of 56 . ° 5 − 1.5 + 1.5 RX J0534 b is one of the lowest-mass planets imaged to date. After TWA 7 b, it is the second imaged planet around an M dwarf orbiting at solar system scales (the first within 40 au) and the first to be confirmed via common proper motion. Future orbital monitoring and atmospheric characterization will shed light on its formation history, a particularly interesting question given the challenging nature of giant planet formation around M dwarfs.
SN  - 2041-8205
SN  - 2041-8213
ER  -