For the first time: Astronomers detect an atmosphere around an Earth-like planet
Astronomers have detected an atmosphere around the super-Earth GJ 1132b. This marks the first detection of an atmosphere around an Earth-like planet other than Earth itself, and thus a significant step on the path towards the detection of life on an exoplanet. The team, which includes researchers from the Max Planck Institute for Astronomy, used the 2.2 m ESO/MPG telescope in Chile to take images of the planet's host star GJ 1132, and measuring the slight decrease in brightness as the planet and its atmosphere absorbed some of the starlight while passing directly in front of their host star. Read more
Title: Detection of the atmosphere of the 1.6 Earth mass exoplanet GJ 1132b Author: John Southworth, Luigi Mancini, Nikku Madhusudhan, Paul Molliere, Simona Ciceri, Thomas Henning
Detecting the atmospheres of low-mass low-temperature exoplanets is a high-priority goal on the path to ultimately detect biosignatures in the atmospheres of habitable exoplanets. High-precision HST observations of several super-Earths with equilibrium temperatures below 1000 K have to date all resulted in featureless transmission spectra, which have been suggested to be due to high-altitude clouds. We report the detection of an atmospheric feature in the atmosphere of a 1.6 Mearth transiting exoplanet, GJ 1132b, with an equilibrium temperature of ~600 K and orbiting a nearby M dwarf. We present observations of nine transits of the planet obtained simultaneously in the griz and JHK passbands. We find an average radius of 1.44 +/- 0.21 Rearth for the planet, averaged over all the passbands, which can be decomposed into a "surface radius" at ~1.35 Rearth, and higher contributions in the z and K bands. The z-band radius is 4 sigma higher than the continuum, suggesting a strong detection of an atmosphere. We deploy a suite of tests to verify the reliability of the transmission spectrum, which are greatly helped by the existence of repeat observations. The large z-band transit depth indicates strong opacity from H2O and/or CH4 or an hitherto unconsidered opacity. A surface radius of 1.35 +/- 0.21 Rearth allows for a wide range of interior compositions ranging from a nearly Earth-like rocky interior, with ~70% silicate and ~30% Fe, to a substantially H2O-rich water world. New observations with HST and existing ground-based facilities would be able to confirm the present detection and further constrain the atmospheric composition of the planet.
Title: A Search for Additional Bodies in the GJ 1132 Planetary System from 21 Ground-based Transits and a 100 Hour Spitzer Campaign Author: Jason A Dittmann, Jonathan M Irwin, David Charbonneau, Zachory K Berta-Thompson, Elisabeth R Newton
We present the results of a search for additional bodies in the GJ 1132 system through two methods: photometric transits and transit timing variations of the known planet. We collected 21 transit observations of GJ 1132b with the MEarth-South array since 2015. We obtained 100 near-continuous hours of observations with the Spitzer Space Telescope, including two transits of GJ 1132b and spanning 60\% of the orbital phase of the maximum period at which bodies coplanar with GJ 1132b would pass in front of the star. We exclude transits of additional Mars-sized bodies, such as a second planet or a moon, with a confidence of 99.7\%. When we combine the mass estimate of the star (obtained from its parallax and apparent K_s band magnitude) with the stellar density inferred from our high-cadence Spitzer light curve (assuming zero eccentricity), we measure the stellar radius of GJ 1132 to be 0.2105^{+0.0102}_{-0.0085} solar radii, and we refine the radius measurement of GJ 1132b to 1.130±0.056 solar radii. Combined with HARPS RV measurements, we determine the density of GJ 1132b to be 6.2±2.0 g cm^-3, with the mass determination dominating this uncertainty. We refine the ephemeris of the system and find no evidence for transit timing variations, which would be expected if there was a second planet near an orbital resonance with GJ 1132b.
The great thing about GJ1132b and GJ667cc for that matter is it was discovered using a ground based telescope. It is really cool that we can do this from the surface!
Two advantages, 1. Ground base last longer then space based telescopes(30-40 years compared to 3-5), and 2. Can be upgraded constantly.
This planet is likely a lot like Venus but quite likely hotter.
Planet GJ 1132b is just 39 light-years away, within the atmospheric study range of the Hubble Space Telescope. Given that a single light-year represents 5.87 trillion miles - the distance light can travel in a year - this planet is about 230 trillion miles away. A team led by Massachusetts Institute of Technology's Zachory Berta-Thompson discovered the planet in May, using telescopes in Chile. He and his colleagues reported their findings Wednesday in the journal Nature. Read more
GJ 1132b could be 'most important planet found outside solar system'
A rocky Earth-sized planet that circles a small, nearby star could be the most important world ever found beyond the solar system, astronomers say. The planet lies in the constellation of Vela in the southern sky and is close enough for telescopes to observe any atmosphere it has, a procedure that could help spot life on other planets in the future. Read more