TOI-3757 b: A low density gas giant orbiting a solar-metallicity M dwarf
| Autor: | Kanodia, Shubham, Libby-Roberts, Jessica, Canas, Caleb I., Ninan, Joe P., Mahadevan, Suvrath, Stefansson, Gudmundur, Lin, Andrea S. J., Jones, Sinclaire, Monson, Andrew, Parker, Brock A., Kobulnicky, Henry A., Swaby, Tera N., Powers, Luke, Beard, Corey, Bender, Chad F., Blake, Cullen H., Cochran, William D., Dong, Jiayin, Diddams, Scott A., Fredrick, Connor, Gupta, Arvind F., Halverson, Samuel, Hearty, Fred, Logsdon, Sarah E., Metcalf, Andrew J., McElwain, Michael W., Morley, Caroline, Rajagopal, Jayadev, Ramsey, Lawrence W., Robertson, Paul, Roy, Arpita, Schwab, Christian, Terrien, Ryan C., Wisniewski, John, Wright, Jason T. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | The Astronomical Journal, Volume 164, Number 3 (2022 AJ 164 81) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/1538-3881/ac7c20 |
| Popis: | We present the discovery of a new Jovian-sized planet, TOI-3757 b, the lowest density planet orbiting an M dwarf (M0V). It orbits a solar-metallicity M dwarf discovered using TESS photometry and confirmed with precise radial velocities (RV) from HPF and NEID. With a planetary radius of $12.0^{+0.4}_{-0.5}$ $R_{\oplus}$ and mass of $85.3^{+8.8}_{-8.7}$ $M_{\oplus}$, not only does this object add to the small sample of gas giants ($\sim 10$) around M dwarfs, but also, its low density ($\rho =$ $0.27^{+0.05}_{-0.04}$ $\textrm{g~cm}^{-3}$) provides an opportunity to test theories of planet formation. We present two hypotheses to explain its low density; first, we posit that the low metallicity of its stellar host ($\sim$ 0.3 dex lower than the median metallicity of M dwarfs hosting gas giants) could have played a role in the delayed formation of a solid core massive enough to initiate runaway accretion. Second, using the eccentricity estimate of $0.14 \pm 0.06$ we determine it is also plausible for tidal heating to at least partially be responsible for inflating the radius of TOI-3757b b. The low density and large scale height of TOI-3757 b makes it an excellent target for transmission spectroscopy studies of atmospheric escape and composition (TSM $\sim$ 190). We use HPF to perform transmission spectroscopy of TOI-3757 b using the helium 10830 \AA~ line. Doing this, we place an upper limit of 6.9 \% (with 90\% confidence) on the maximum depth of the absorption from the metastable transition of He at $\sim$ 10830 \AA, which can help constraint the atmospheric mass loss rate in this energy limited regime. Comment: AJ. arXiv admin note: text overlap with arXiv:2107.13670 |
| Databáze: | arXiv |
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