The Multiplanet System TOI-421
(2020) In Astronomical Journal 160(3).- Abstract
We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations - comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echellé Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution chelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements - and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional... (More)
We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations - comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echellé Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution chelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements - and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of P b = 5.19672 ± 0.00049 days, a mass of M b = 7.17 ± 0.66 M ⊕, and a radius of R b = 2.68-0.18+0.19 R ⊕, whereas the outer warm Neptune, TOI-421 c, has a period of P c = 16.06819 ± 0.00035 days, a mass of M c = 16.42-1.04+1.06 M ⊕, a radius of R c = 5.09-0.15+0.16 R ⊕, and a density of ρ c = 0.685-0.072+0.080 g cm-3. With its characteristics, the outer planet (ρ c = 0.685-0.072+0.080 g cm-3) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Lyα transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed.
(Less)
- author
- publishing date
- 2020-09
- type
- Contribution to journal
- publication status
- published
- in
- Astronomical Journal
- volume
- 160
- issue
- 3
- article number
- aba124
- publisher
- IOP Publishing
- external identifiers
-
- scopus:85093505241
- ISSN
- 0004-6256
- DOI
- 10.3847/1538-3881/aba124
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2020. The American Astronomical Society. All rights reserved.
- id
- 37f6f81b-d741-4b97-b385-2385a45cf040
- date added to LUP
- 2023-02-02 09:14:35
- date last changed
- 2023-02-21 11:22:04
@article{37f6f81b-d741-4b97-b385-2385a45cf040,
abstract = {{<p>We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations - comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echellé Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution chelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements - and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of P b = 5.19672 ± 0.00049 days, a mass of M b = 7.17 ± 0.66 M ⊕, and a radius of R b = 2.68-0.18+0.19 R ⊕, whereas the outer warm Neptune, TOI-421 c, has a period of P c = 16.06819 ± 0.00035 days, a mass of M c = 16.42-1.04+1.06 M ⊕, a radius of R c = 5.09-0.15+0.16 R ⊕, and a density of ρ c = 0.685-0.072+0.080 g cm-3. With its characteristics, the outer planet (ρ c = 0.685-0.072+0.080 g cm-3) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Lyα transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed.</p>}},
author = {{Carleo, Ilaria and Gandolfi, Davide and Barragán, Oscar and Livingston, John H. and Persson, Carina M. and Lam, Kristine W.F. and Vidotto, Aline and Lund, Michael B. and D'angelo, Carolina Villarreal and Collins, Karen A. and Fossati, Luca and Howard, Andrew W. and Kubyshkina, Daria and Brahm, Rafael and Oklopčić, Antonija and Molli re, Paul and Redfield, Seth and Serrano, Luisa Maria and Dai, Fei and Fridlund, Malcolm and Borsa, Francesco and Korth, Judith and Esposito, Massimiliano and Díaz, Matías R. and Nielsen, Louise Dyregaard and Hellier, Coel and Mathur, Savita and Deeg, Hans J. and Hatzes, Artie P. and Benatti, Serena and Rodler, Florian and Alarcon, Javier and Spina, Lorenzo and Santos, Angela R.G. and Georgieva, Iskra and García, Rafael A. and González-Cuesta, Lucía and Ricker, George R. and Vanderspek, Roland and Latham, David W. and Seager, Sara and Winn, Joshua N. and Jenkins, Jon M. and Albrecht, Simon and Batalha, Natalie M. and Beard, Corey and Boyd, Patricia T. and Bouchy, Fran ois and Burt, Jennifer A. and Butler, R. Paul and Cabrera, Juan and Chontos, Ashley and Ciardi, David R. and Cochran, William D. and Collins, Kevin I. and Crane, Jeffrey D. and Crossfield, Ian and Csizmadia, Szilard and Dragomir, Diana and Dressing, Courtney and Eigmüller, Philipp and Endl, Michael and Erikson, Anders and Espinoza, Nestor and Fausnaugh, Michael and Feng, Fabo and Flowers, Erin and Fulton, Benjamin and Gonzales, Erica J. and Grieves, Nolan and Grziwa, Sascha and Guenther, Eike W. and Guerrero, Natalia M. and Henning, Thomas and Hidalgo, Diego and Hirano, Teruyuki and Hjorth, Maria and Huber, Daniel and Isaacson, Howard and Jones, Matias and Jordán, Andrés and Kabáth, Petr and Kane, Stephen R. and Knudstrup, Emil and Lubin, Jack and Luque, Rafael and Mireles, Ismael and Narita, Norio and Nespral, David and Niraula, Prajwal and Nowak, Grzegorz and Palle, Enric and Patzold, Martin and Petigura, Erik A. and Prieto-Arranz, Jorge and Rauer, Heike and Robertson, Paul and Rose, Mark E. and Roy, Arpita and Sarkis, Paula and Schlieder, Joshua E. and Ségransan, Damien and Shectman, Stephen and Skarka, Marek and Smith, Alexis M.S. and Smith, Jeffrey C. and Stassun, Keivan and Teske, Johanna and Twicken, Joseph D. and Eylen, Vincent Van and Wang, Sharon and Weiss, Lauren M. and Wyttenbach, Aurélien}},
issn = {{0004-6256}},
language = {{eng}},
number = {{3}},
publisher = {{IOP Publishing}},
series = {{Astronomical Journal}},
title = {{The Multiplanet System TOI-421}},
url = {{http://dx.doi.org/10.3847/1538-3881/aba124}},
doi = {{10.3847/1538-3881/aba124}},
volume = {{160}},
year = {{2020}},
}