| Autor: |
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 |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
|
| Zdroj: |
The Astronomical Journal, Vol 167, Iss 6, p 282 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
1538-3881 |
| DOI: |
10.3847/1538-3881/ad34d9 |
| Popis: |
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. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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