Results tagged “Exoplanet”

Nitrogen is a biosignature gas that cannot be maintained in its Earth-like ratio with CO2 under abiotic conditions. It has also proven to be notoriously hard to detect at optical and infrared wavelengths.

The Demographics of Exoplanets

In the broadest sense, the primary goal of exoplanet demographic surveys is to determine the frequency and distribution of planets as a function of as many of the physical parameters that may influence planet formation and evolution as possible, over as broad of a range of these parameters as possible.

Clouds In Exoplanetary Atmospheres

Today, we know ~4330 exoplanets orbiting their host stars in ~3200 planetary systems. The diversity of these exoplanets is large, and none of the known exoplanets is a twin to any of the solar system planets, nor is any of the known extrasolar planetary systems a twin of the solar system.

One of the most promising avenues for the detailed study of temperate Earth-sized exoplanets is the detection of such planets in transit in front of stars small and nearby enough to make possible their thorough atmospheric characterisation with next generation telescopes like the James Webb Space telescope (JWST) or Extremely Large Telescope (ELT).

We report the discovery of a Neptune-like planet (LP 714-47 b, P = 4.05204 d, m_b = 30.8 +/- 1.5 M_earth , R_b = 4.7 +/- 0.3 R_earth ) located in the 'hot Neptune desert'.

A large fraction of stars are formed in dense clusters. In the cluster, close encounters between stars at distances less than 100 au are common.

We show that in extremely irradiated atmospheres of hot super-Earths shortwave absorption of CN can cause strong temperature inversions.

The discovery of thousands of highly irradiated, low-mass, exoplanets has led to the idea that atmospheric escape is an important process that can drive their evolution.

Most of our current knowledge on planet formation is still based on the analysis of main-sequence, solar-type stars.

TESS, the Transiting Exoplanet Survey Satellite, was launched in 2018 with the goal of discovering small planets around the Sun's nearest neighbors, stars bright enough to allow for follow-up characterizations of their planets' masses and atmospheres.

With the discovery of TRAPPIST-1 and its seven planets within 0.06 au, the correct treatment of tidal interactions is becoming necessary. The eccentricity, rotation, and obliquity of the planets of TRAPPIST-1 are indeed the result of tidal evolution over the lifetime of the system.

For the time being, Earth remains the best and only example of a habitable (and inhabited) world.

We announce the discovery of two planets orbiting the M dwarfs GJ 251 (0.360±0.015 M⊙) and HD 238090 (0.578±0.021 M⊙) based on CARMENES radial velocity (RV) data.

University of Warwick astronomers have shown that water vapour can potentially be detected in the atmospheres of exoplanets by peering literally over the tops of their impenetrable clouds.

Direct imaging of widely separated exoplanets from space will obtain their reflected light spectra and measure atmospheric properties.

M dwarf stars are excellent candidates around which to search for exoplanets, including temperate, Earth-sized planets. To evaluate the photochemistry of the planetary atmosphere, it is essential to characterize the UV spectral energy distribution of the planet's host star.

In anticipation of future flagship missions focused on the goal of achieving direct imaging of rocky exoplanets, we have developed a database of models to help the community examine the potential spectral characteristics of a broad range of rocky planet atmospheres.

The detectability of exoplanets and the determination of their projected mass in radial velocity are affected by stellar magnetic activity and photospheric dynamics.

New observing capabilities coming online over the next few years will provide opportunities for characterization of exoplanet atmospheres. However, clouds/hazes could be present in the atmospheres of many exoplanets, muting the amplitude of spectral features.

Combining isotopic constraints from meteorite data with dynamical models of planet formation proves to be advantageous in identifying the best model for terrestrial planet formation.

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