The Astronomical Journal (Jan 2024)
The TESS-Keck Survey. VII. A Superdense Sub-Neptune Orbiting TOI-1824
- Sarah Lange,
- Joseph M. Akana Murphy,
- Natalie M. Batalha,
- Ian J. M. Crossfield,
- Courtney D. Dressing,
- Benjamin Fulton,
- Andrew W. Howard,
- Daniel Huber,
- Howard Isaacson,
- Stephen R. Kane,
- Erik A. Petigura,
- Paul Robertson,
- Lauren M. Weiss,
- Aida Behmard,
- Corey Beard,
- Sarah Blunt,
- Casey L. Brinkman,
- Ashley Chontos,
- Fei Dai,
- Paul A. Dalba,
- Tara Fetherolf,
- Steven Giacalone,
- Michelle L. Hill,
- Rae Holcomb,
- Jack Lubin,
- Mason G. MacDougall,
- Andrew W. Mayo,
- Teo Močnik,
- Daria Pidhorodetska,
- Alex S. Polanski,
- Malena Rice,
- Lee J. Rosenthal,
- Ryan A. Rubenzahl,
- Nicholas Scarsdale,
- Emma V. Turtelboom,
- Judah Van Zandt,
- David R. Ciardi,
- Andrew W. Boyle
Affiliations
- Sarah Lange
- ORCiD
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- Joseph M. Akana Murphy
- ORCiD
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- Natalie M. Batalha
- ORCiD
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- Ian J. M. Crossfield
- Department of Physics and Astronomy, University of Kansas , Lawrence, KS 66045, USA
- Courtney D. Dressing
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Benjamin Fulton
- ORCiD
- NASA Exoplanet Science Institute/Caltech-IPAC , Pasadena, CA 91125, USA
- Andrew W. Howard
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Daniel Huber
- ORCiD
- Institute for Astronomy, University of Hawai‘i , Honolulu, HI 96822, USA; Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney , NSW 2006, Australia
- Howard Isaacson
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA; Centre for Astrophysics, University of Southern Queensland , Toowoomba, QLD, Australia
- Stephen R. Kane
- ORCiD
- Department of Earth and Planetary Sciences, University of California , Riverside, CA 92521, USA
- Erik A. Petigura
- ORCiD
- Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA
- Paul Robertson
- ORCiD
- Department of Physics and Astronomy, University of California , Irvine, CA 92697, USA
- Lauren M. Weiss
- ORCiD
- Department of Physics and Astronomy, University of Notre Dame , Notre Dame, IN 46556, USA
- Aida Behmard
- ORCiD
- Department of Astrophysics, American Museum of Natural History , 200 Central Park West, Manhattan, NY 10024, USA
- Corey Beard
- ORCiD
- Department of Physics and Astronomy, University of California , Irvine, CA 92697, USA
- Sarah Blunt
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA; Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University , Evanston, IL 60208, USA
- Casey L. Brinkman
- ORCiD
- Institute for Astronomy, University of Hawai‘i , Honolulu, HI 96822, USA
- Ashley Chontos
- ORCiD
- Institute for Astronomy, University of Hawai‘i , Honolulu, HI 96822, USA; Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08540, USA
- Fei Dai
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA; Division of Geological and Planetary Sciences , 1200 East California Boulevard, Pasadena, CA 91125, USA
- Paul A. Dalba
- ORCiD
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- Tara Fetherolf
- ORCiD
- Department of Earth and Planetary Sciences, University of California , Riverside, CA 92521, USA; Department of Physics, California State University , San Marcos, CA 92096, USA
- Steven Giacalone
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Michelle L. Hill
- ORCiD
- Department of Earth and Planetary Sciences, University of California , Riverside, CA 92521, USA
- Rae Holcomb
- ORCiD
- Department of Physics and Astronomy, University of California Irvine , Irvine, CA 92697, USA
- Jack Lubin
- ORCiD
- Department of Physics and Astronomy, University of California , Irvine, CA 92697, USA; Department of Physics & Astronomy, University of California Los Angeles , Los Angeles, CA 90095, USA
- Mason G. MacDougall
- ORCiD
- Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA
- Andrew W. Mayo
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Teo Močnik
- ORCiD
- Gemini Observatory/NSF’s NOIRLab , Hilo, HI 96720, USA
- Daria Pidhorodetska
- ORCiD
- Department of Earth and Planetary Sciences, University of California , Riverside, CA 92521, USA
- Alex S. Polanski
- ORCiD
- Department of Physics and Astronomy, University of Kansas , Lawrence, KS 66045, USA
- Malena Rice
- ORCiD
- Department of Astronomy, Yale University , New Haven, CT 06511, USA
- Lee J. Rosenthal
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Ryan A. Rubenzahl
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Nicholas Scarsdale
- ORCiD
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- Emma V. Turtelboom
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Judah Van Zandt
- ORCiD
- Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA
- David R. Ciardi
- ORCiD
- NASA Exoplanet Science Institute-Caltech/IPAC , Pasadena, CA 91125, USA
- Andrew W. Boyle
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- DOI
- https://doi.org/10.3847/1538-3881/ad34d9
- Journal volume & issue
-
Vol. 167,
no. 6
p. 282
Abstract
We confirm a massive sub-Neptune-sized planet on a P = 22.8 days orbit around the star TOI-1824 ( T _eff = 5200 K, V = 9.7 mag). TESS first identified TOI-1824 b (formerly TOI-1824.01) as an object of interest in 2020 April after two transits in Sector 22 were matched with a single transit in Sector 21. TOI-1824 was subsequently targeted for ground-based Doppler monitoring with Keck-HIRES and APF-Levy. Using a joint model of the TESS photometry, radial velocities, and Ca ii H and K emission measurements as an activity indicator, we find that TOI-1824 b is an unusually dense sub-Neptune. The planet has a radius R _p = 2.63 ± 0.15 R _⊕ and mass M _p = 18.5 ± 3.2 M _⊕ , implying a bulk density of 5.6 ± 1.4 g cm ^−3 . TOI-1824 b's mass and radius situate it near a small group of “superdense sub-Neptunes” ( R _p ≲ 3 R _⊕ and M _p ≳ 20 M _⊕ ). While the formation mechanism of superdense sub-Neptunes is a mystery, one possible explanation is the constructive collision of primordial icy cores; such giant impacts would drive atmospheric escape and could help explain these planets' apparent lack of massive envelopes. We discuss TOI-1824 b in the context of these overdense planets, whose unique location in the exoplanet mass–radius plane make them a potentially valuable tracer of planet formation.
Keywords
