Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1

By M. Gillon, A. Triaud, B. Demory, E. Jehin, E. Agol, K. Deck, S. Lederer, J. de Wit, A. Burdanov, J. Ingalls and 20 more. Nature, 2017

1,214 citations recorded by the source corpus.

One aim of modern astronomy is to detect temperate, Earth-like exoplanets that are well suited for atmospheric characterization. Recently, three Earth-sized planets were detected that transit (that is, pass in front of) a star with a mass just eight per cent that of the Sun, located 12 parsecs away. The transiting configuration of these planets, combined with the Jupiter-like size of their host star—named TRAPPIST-1—makes possible in-depth studies of their atmospheric properties with present-day and future astronomical facilities. Here we report the results of a photometric monitoring campaign of that star from the ground and space. Our observations reveal that at least seven planets with sizes and masses similar to those of Earth revolve around TRAPPIST-1. The six inner planets form a near-resonant chain, such that their orbital periods (1.51, 2.42, 4.04, 6.06, 9.1 and 12.35 days) are near-ratios of small integers. This architecture suggests that the planets formed farther from the star and migrated inwards. Moreover, the seven planets have equilibrium temperatures low enough to make possible the presence of liquid water on their surfaces.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/aa3ccc6566b3db50f444c4f7c3588cbde6d26788

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Citations in the corpus

• A Revised Exoplanet Yield from the Transiting Exoplanet Survey Satellite (TESS) (2018, background): “These planets, along with those orbiting TRAPPIST-1 (Gillon et al. 2017) and other low-mass stars (Greene et al. 2016; Kreidberg & Loeb 2016; Morley et al. 2017; Louie et al. 2018), will form a reference sample of temperate worlds for observation by JWST.”
• Atmospheric reconnaissance of the habitable-zone Earth-sized planets orbiting TRAPPIST-1 (2018, methodology): “We therefore use the physically-relevant following ramp model: Fobs(t) F (t) = rv(t)ro(t), (1) where rv(t) is the ramp induced by the progressive stabilization of the charge-trapping, rv(t) = (1 + a1e − t a2 ), (2) ro(t), is the ramp induced by the charge-trapping effect (i.”
• Frequent Flaring in the TRAPPIST-1 System—Unsuited for Life? (2017, background): “TRAPPIST-1 (2MASS J23062928-0502285) is an ultracool, M8-type dwarf, which is known to host seven terrestrial planets, with three of them having equilibrium temperatures that makes the existence of liquid water on their surface possible (Gillon et al. 2016, 2017).”
• Disentangling the Planet from the Star in Late-Type M Dwarfs: A Case Study of TRAPPIST-1g (2018, background): “The TRAPPIST-1 system has been the subject of many investigations since the discovery of seven Earthsized worlds orbiting this ultra-cool M dwarf (Gillon et al. 2016, 2017).”
• How to Characterize Habitable Worlds and Signs of Life (2017, background): “In the close-by TRAPPIST-1 planetary system, three to four Earth-size planets orbit in the HZ of its M9V host star only about 12 pc from the Sun (Gillon et al. 2017).”
• The Surface UV Environment on Planets Orbiting M Dwarfs: Implications for Prebiotic Chemistry and the Need for Experimental Follow-up (2017, background): “In sum, it is unclear whether UV-dependent prebiotic pathways that may have been important to the origin of life on Earth can proceed in the low-UV environment on planets orbiting Mdwarfs, such as the recently discovered habitable-zone planets Proxima Centauri b (Anglada-Escudé et al. 2016), LHS 114”
• A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization (2018, methodology): “The TSM values and planet parameters for the top 10 simulated planets are given in Table 2, benchmarked against the known planets LHS 1140b (Dittmann et al. 2017) and TRAPPIST1f (Gillon et al. 2017; Grimm et al. 2018).”
• The Transit Light Source Effect: False Spectral Features and Incorrect Densities for M-dwarf Transiting Planets (2017, methodology): “The shaded region in this panel illustrates the range of feature scales for the six innermost TRAPPIST-1 planets, calculated using the planetary parameters from Gillon et al. (2017) and assuming an Earth-like atmospheric mean molecular weight (µ = 28.97 amu).”
• Habitability from Tidally Induced Tectonics (2018, background): “This mechanism would be highly relevant for planets that have non-zero eccentricities orbiting in the habitable zones of M stars, such as three of the seven planets of the Trappist-one system (Gillon et al. 2017).”
• Why do protoplanetary disks appear not massive enough to form the known exoplanet population? (2018, background): “3, the heavy element content in exoplanetary systems can be as high as ∼2–3 MJ for solar mass stars, and 0.02 MJ , about 6.4 M⊕, around brown dwarfs (e.g., the TRAPPIST1 system, Gillon et al. 2017).”
• Stellar Flares from the First TESS Data Release: Exploring a New Sample of M Dwarfs (2019, background): “For example, we know three exoEarths in the ‘liquid-water habitable zone’1 of the red dwarf TRAPPIST-1 (Gillon et al. 2017), one around LHS 1140b (Dittmann et al. 2017), and one around Proxima Centauri (Anglada-Escudé et al. 2016).”
• Evolved Climates and Observational Discriminants for the TRAPPIST-1 Planetary System (2018, methodology): “Here we adopt the current best-fit orbital periods,radii, and masses of the TRAPPIST-1 planets (see Table 1 and Gillon et al. 2016, 2017; Luger et al. 2017b; Grimm et al. 2018).”
• Optimized transit detection algorithm to search for periodic transits of small planets (2019, background): “The well-studied TRAPPIST-1 system exhibits transits of seven terrestrial planets (Gillon et al. 2016, 2017) in a resonant chain, where the orbital periods are near-ratios of small integers (Luger et al. 2017).”
• Assessing the Habitability of the TRAPPIST-1 System Using a 3D Climate Model (2017, methodology): “Gillon et al. (2017) suggest that the seven TRAPPIST-1 planets may be “temperate” because all have equilibrium temperatures below ∼400 K.”
• Identifying Exoplanets with Deep Learning: A Five-planet Resonant Chain around Kepler-80 and an Eighth Planet around Kepler-90 (2017, methodology): “According to the NASA Exoplanet Archive (accessed 19 August 2017), only Kepler-90 and TRAPPIST-1 (Gillon et al. 2017) are known to host this many planets18.”
• How to Constrain Your M Dwarf. II. The Mass–Luminosity–Metallicity Relation from 0.075 to 0.70 Solar Masses (2018, background): “Existing relations also have gaps in their calibration sample, particularly below 0.1M , where there is need for stellar masses to match new exoplanet surveys (e.g., Gillon et al. 2017).”
• The CARMENES search for exoplanets around M dwarfs (2018, background): “Furthermore, the TRAPPIST-1 system was detected by transit search and the planet’s dynamical masses have been inferred from transit timing variations (Gillon et al. 2017; Grimm et al. 2018).”