dc.contributor.author | Wakeford, HR | |
dc.contributor.author | Lewis, NK | |
dc.contributor.author | Fowler, J | |
dc.contributor.author | Bruno, G | |
dc.contributor.author | Wilson, TJ | |
dc.contributor.author | Moran, SE | |
dc.contributor.author | Valenti, J | |
dc.contributor.author | Batalha, NE | |
dc.contributor.author | Filippazzo, J | |
dc.contributor.author | Bourrier, V | |
dc.contributor.author | Hörst, SM | |
dc.contributor.author | Lederer, SM | |
dc.contributor.author | de Wit, J | |
dc.date.accessioned | 2022-01-18T19:29:35Z | |
dc.date.available | 2021-10-27T19:56:34Z | |
dc.date.available | 2022-01-18T19:29:35Z | |
dc.date.issued | 2018-12 | |
dc.date.submitted | 2018-11 | |
dc.identifier.issn | 1538-3881 | |
dc.identifier.uri | https://hdl.handle.net/1721.1/133773.2 | |
dc.description.abstract | © 2018. The American Astronomical Society. All rights reserved. The atmospheres of late M stars represent a significant challenge in the characterization of any transiting exoplanets because of the presence of strong molecular features in the stellar atmosphere. TRAPPIST-1 is an ultracool dwarf, host to seven transiting planets, and contains its own molecular signatures that can potentially be imprinted on planetary transit lightcurves as a result of inhomogeneities in the occulted stellar photosphere. We present a case study on TRAPPIST-1g, the largest planet in the system, using a new observation together with previous data, to disentangle the atmospheric transmission of the planet from that of the star. We use the out-of-transit stellar spectra to reconstruct the stellar flux on the basis of one, two, and three temperature components. We find that TRAPPIST-1 is a 0.08 M ∗, 0.117 R ∗, M8V star with a photospheric effective temperature of 2400 K, with ∼35% 3000 K spot coverage and a very small fraction, <3%, of ∼5800 K hot spot. We calculate a planetary radius for TRAPPIST-1g to be R p = 1.124 R ⊕with a planetary density of ρ p = 0.8214 ρ ⊕. On the basis of the stellar reconstruction, there are 11 plausible scenarios for the combined stellar photosphere and planet transit geometry; in our analysis, we are able to rule out eight of the 11 scenarios. Using planetary models, we evaluate the remaining scenarios with respect to the transmission spectrum of TRAPPIST-1g. We conclude that the planetary transmission spectrum is likely not contaminated by any stellar spectral features and are able to rule out a clear solar H2/He-dominated atmosphere at greater than 3σ. | en_US |
dc.language.iso | en | |
dc.publisher | American Astronomical Society | en_US |
dc.relation.isversionof | http://dx.doi.org/10.3847/1538-3881/AAF04D | en_US |
dc.rights | Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. | en_US |
dc.source | The American Astronomical Society | en_US |
dc.title | Disentangling the Planet from the Star in Late-Type M Dwarfs: A Case Study of TRAPPIST-1g | en_US |
dc.type | Article | en_US |
dc.contributor.department | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences | |
dc.relation.journal | Astronomical Journal | en_US |
dc.eprint.version | Final published version | en_US |
dc.type.uri | http://purl.org/eprint/type/JournalArticle | en_US |
eprint.status | http://purl.org/eprint/status/PeerReviewed | en_US |
dc.date.updated | 2021-09-14T18:00:45Z | |
dspace.orderedauthors | Wakeford, HR; Lewis, NK; Fowler, J; Bruno, G; Wilson, TJ; Moran, SE; Valenti, J; Batalha, NE; Filippazzo, J; Bourrier, V; Hörst, SM; Lederer, SM; de Wit, J | en_US |
dspace.date.submission | 2021-09-14T18:00:47Z | |
mit.journal.volume | 157 | en_US |
mit.journal.issue | 1 | en_US |
mit.license | PUBLISHER_POLICY | |
mit.metadata.status | Authority Work Needed | en_US |