Extrasolar Planets


Implications of Tides for Life on Exoplanets

Implications of Tides for Life on Exoplanets

As evident from the nearby examples of Proxima Centauri and TRAPPIST-1, Earth-sized planets in the habitable zone of low-mass stars are common. Here, we focus on such planetary systems and argue that their (oceanic) tides could be more prominent due to stronger tidal forces.


A New Search for Extrasolar Planets Around Barnard's Star

A New Search for Extrasolar Planets Around Barnard's Star

The National Science Foundation's Arecibo Observatory and the Planetary Habitability Laboratory of the University of Puerto Rico at Arecibo joined the Red Dots project in the search for new planets around our nearest stars.


Exoplanet Transits as the Foundation of an Interstellar Communications Network

Exoplanet Transits as the Foundation of an Interstellar Communications Network

Two fundamental problems for extraterrestrial intelligences (ETIs) attempting to establish interstellar communication are timing and energy consumption.


Exoplanets and SETI

Exoplanets and SETI

The discovery of exoplanets has both focused and expanded the search for extraterrestrial intelligence.


New Branch in Family Tree of Exoplanets Discovered

New Branch in Family Tree of Exoplanets Discovered

Since the mid-1990s, when the first planet around another Sun-like star was discovered, astronomers have been amassing what is now a large collection of exoplanets -- nearly 3,500 have been confirmed so far.


Stable Habitable Zones of Single Jovian Planet Systems

Stable Habitable Zones of Single Jovian Planet Systems

With continued improvement in telescope sensitivity and observational techniques, the search for rocky planets in stellar habitable zones is entering an exciting era. With so many exoplanetary systems available for follow-up observations to find potentially habitable planets, one needs to prioritise the ever-growing list of candidates.


A Statistical Approach to Search for Earth-like Planets

A Statistical Approach to Search for Earth-like Planets

A team of astronomers at the University of Chicago and Grinnell College seeks to change the way scientists approach the search for Earth-like planets orbiting stars other than the sun.


Searching for Exoplanets Using Artificial Intelligence

Searching for Exoplanets Using Artificial Intelligence

In the last decade, over a million stars were monitored to detect transiting planets. Manual interpretation of potential exoplanet candidates is labor intensive and subject to human error, the results of which are difficult to quantify.


A new statistical method for characterizing the atmospheres of extrasolar planets

A new statistical method for characterizing the atmospheres of extrasolar planets

By detecting light from extrasolar planets,we can measure their compositions and bulk physical properties. The technologies used to make these measurements are still in their infancy, and a lack of self-consistency suggests that previous observations have underestimated their systemic errors.


Quantitative Estimates of the Surface Habitability of Kepler-452b

Quantitative Estimates of the Surface Habitability of Kepler-452b

Kepler-452b is currently the best example of an Earth-size planet in the habitable zone of a sun-like star, a type of planet whose number of detections is expected to increase in the future.


Comparative Planetology: HAT-P-38 b and WASP-67 b

Comparative Planetology: HAT-P-38 b and WASP-67 b

In a unique experiment, scientists used NASA's Hubble Space Telescope to study two "hot Jupiter" exoplanets. Because these planets are virtually the same size and temperature, and orbit around nearly identical stars at the same distance, the team hypothesized that their atmospheres should be alike. What they found surprised them.


On Signatures of Clouds in Exoplanetary Transit Spectra

On Signatures of Clouds in Exoplanetary Transit Spectra

Transmission spectra of exoplanetary atmospheres have been used to infer the presence of clouds/hazes. Such inferences are typically based on spectral slopes in the optical deviant from gaseous Rayleigh scattering or low-amplitude spectral features in the infrared.


Formation of Solar System Analogs

Formation of Solar System Analogs

Population synthesis models of planetary systems developed during the last ∼15 years could reproduce several of the observables of the exoplanet population, and also allowed to constrain planetary formation models. We present our planet formation model, which calculates the evolution of a planetary system during the gaseous phase.


Exoplanet Biosignatures: Future Directions

Exoplanet Biosignatures: Future Directions

Exoplanet science promises a continued rapid accumulation of rocky planet observations in the near future, energizing a drive to understand and interpret an unprecedented wealth of data to search for signs of life. The large statistics of exoplanet samples, combined with the ambiguity of our understanding of universal properties of life and its signatures, necessitate a quantitative framework for biosignature assessment.


Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment

Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment

Here we review how environmental context can be used to interpret whether O2 is a biosignature in extrasolar planetary observations. This paper builds on the overview of current biosignature research discussed in Schwieterman et al. (2017), and provides an in-depth, interdisciplinary example of biosignature identification and observation that serves as a basis for the development of the general framework for biosignature assessment described in Catling et al., (2017).


Neutron Star Planets: Atmospheric Processes and Habitability

Neutron Star Planets: Atmospheric Processes and Habitability

Of the roughly 3000 neutron stars known, only a handful have sub-stellar companions. The most famous of these are the low-mass planets around the millisecond pulsar B1257+12. New evidence indicates that observational biases could still hide a wide variety of planetary systems around most neutron stars.


Exoplanet Biosignatures: Observational Prospects

Exoplanet Biosignatures: Observational Prospects

We provide an overview of the prospects for biosignature detection and general characterization of temperate Earth-sized planets. We review planned space-based missions and ground-based projects as well as the basic methods they will employ, and summarize which exoplanet properties will become observable as these new facilities come on line.


Exoplanet Biosignatures: A Framework for Their Assessment

Exoplanet Biosignatures: A Framework for Their Assessment

Finding life on exoplanets from telescopic observations is the ultimate goal of exoplanet science. Life produces gases and other substances, such as pigments, which can have distinct spectral or photometric signatures. Whether or not life is found in future data must be expressed with probabilities, requiring a framework for biosignature assessment.


A Super-Earth on the Inner Edge of the Habitable Zone of the Nearby M-dwarf GJ 625

A Super-Earth on the Inner Edge of the Habitable Zone of the Nearby M-dwarf GJ 625

We report the discovery of a super-Earth orbiting at the inner edge of the habitable zone of the star GJ 625 based on the analysis of the radial-velocity (RV) time series from the HARPS-N spectrograph, consisting in 151 HARPS-N measurements taken over 3.5 yr. GJ 625 b is a planet with a minimum mass M sin i of 2.82 ± 0.51 M⊕ with an orbital period of 14.628 ± 0.013 days at a distance of 0.078 AU of its parent star.


A Statistical Comparative Planetology Approach to the Hunt for Habitable Exoplanets and Life Beyond the Solar System

A Statistical Comparative Planetology Approach to the Hunt for Habitable Exoplanets and Life Beyond the Solar System

The search for habitable exoplanets and life beyond the Solar System is one of the most compelling scientific opportunities of our time.



Top stories from July.