ann1703a — Announcement

Seven potentially habitable worlds confirmed orbiting nearby star

Hubble screens exoplanets for traces of atmosphere

22 February 2017

Astronomers using telescopes in space and on the ground have found a total of seven Earth-sized, potentially habitable exoplanets orbiting the ultracool dwarf star TRAPPIST-1, 40 light-years away. This makes TRAPPIST-1 the solar system with the largest number of Earth-sized planets so far discovered.

The NASA/ESA Hubble Space Telescope has also scrutinised this interesting planet system. Following up on the discovery, Hubble is screening the six innermost planets looking for evidence for atmospheres. These observations, in the infrared and performed with the Wide Field Camera 3 (WFC3), will provide further information about the nature of the planets. The analysis of the data and the publication process are currently in progress.

In addition, Hubble’s Space Telescope Imaging Spectrograph (STIS) already observed the two innermost planets in the ultraviolet to determine the amount of irradiation they receive from their parent star. However, the first results gathered with STIS, published in a new paper, are inconclusive with respect to the composition of the planets’ atmospheres and more observations in the ultraviolet by Hubble are needed to draw a conclusion.

More Information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The discovery of the exoplanets was presented in a paper entitled Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1, by M. Gillon et al., to appear in the journal Nature.

The ultraviolet study was presented in the paper Reconnaissance of the TRAPPIST-1 exoplanet system in the Lyman-α line by V. Bourrier et al., to appear in the journal Astronomy & Astrophysics.

The team that carried out the ultraviolet study is composed of V. Bourrier (Observatoire de l’Université de Genève, Switzerland), D. Ehrenreich (Observatoire de l’Université de Genève, Switzerland), P. J. Wheatley (University of Warwick, UK), E. Bolmont University of Namur, Belgium; Laboratoire AIM Paris-Saclay, CEA/DRF - CNRS - Univ. Paris Diderot - IRFU/SAp, Centre de Saclay, France), M. Gillon (Université de Liège, Belgium), J. de Witt (Massachusetts Institute of Technology, USA), A. J. Burgasser (University of California San Diego, USA), E. Jehin (Université de Liège, Belgium), D. Queloz (Cavendish Laboratory, UK), A. H. M. J. Triaud (Institute of Astronomy, Cambridge, UK)



Vincent Bourrier
Observatoire de l’Université de Genève
Sauverny, Switzerland
Tel: +41 22 379 24 49

David Ehrenreich
Observatoire de l’Université de Genève
Sauverny, Switzerland
Tel: +41 22 379 23 90

Mathias Jäger
ESA/Hubble, Public Information Officer
Garching bei München, Germany
Cell: +49 176 62397500

About the Announcement



Artist’s impression of the TRAPPIST-1 planetary system
Artist’s impression of the TRAPPIST-1 planetary system

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