Extrasolar Planets


Habitable Worlds With JWST: Transit Spectroscopy of the TRAPPIST-1 System?

Habitable Worlds With JWST: Transit Spectroscopy of the TRAPPIST-1 System?

The recent discovery of three Earth-sized, potentially habitable planets around a nearby cool star, TRAPPIST-1, has provided three key targets for the upcoming James Webb Space Telescope (JWST).


Impact of Secular Resonances on Habitable Zones in Circumstellar Planetary Systems of Known Binary Stars

Impact of Secular Resonances on Habitable Zones in Circumstellar Planetary Systems of Known Binary Stars

We present a survey on binary star systems with stellar separations less than 100 astronomical units.


Using Kepler Candidates to Examine the Properties of Habitable Zone Exoplanets

Using Kepler Candidates to Examine the Properties of Habitable Zone Exoplanets

An analysis of the currently known exoplanets in the habitable zones (HZs) of their host stars is of interest in both the wake of the NASA Kepler mission and with prospects for expanding the known planet population through future ground- and space-based projects.


Probability of CME Impact on Exoplanets Orbiting M Dwarfs and Solar-Like Stars

Probability of CME Impact on Exoplanets Orbiting M Dwarfs and Solar-Like Stars

Solar coronal mass ejections (CMEs) produce adverse space weather effects at Earth. Planets in the close habitable zone of magnetically active M dwarfs may experience more extreme space weather than at Earth, including frequent CME impacts leading to atmospheric erosion and leaving the surface exposed to extreme flare activity.


Kepler Confirms 1,284 New Planets

Kepler Confirms 1,284 New Planets

Scientists from Princeton University and NASA have confirmed that 1,284 objects observed outside Earth's solar system by NASA's Kepler spacecraft are indeed planets.


Temperature Structure and Atmospheric Circulation of Dry, Tidally Locked Rocky Exoplanets

Temperature Structure and Atmospheric Circulation of Dry, Tidally Locked Rocky Exoplanets

Next-generation space telescopes will observe the atmospheres of rocky planets orbiting nearby M-dwarfs. Understanding these observations will require well-developed theory in addition to numerical simulations.


Survival of Habitable Planets in Unstable Planetary Systems

Survival of Habitable Planets in Unstable Planetary Systems

Many observed giant planets lie on eccentric orbits. Such orbits could be the result of strong scatterings with other giant planets. The same dynamical instability that produces giant planet scatterings can also alter the orbits of terrestrial planets.


Water Loss From Earth-sized Planets in Ultracool Dwarf Habitable Zones

Water Loss From Earth-sized Planets in Ultracool Dwarf Habitable Zones

Ultracool dwarfs (UCD) encompass the population of extremely low mass stars (later than M6-type) and brown dwarfs.


Three Potentially Habitable Worlds Found Around Nearby Ultracool Dwarf Star

Three Potentially Habitable Worlds Found Around Nearby Ultracool Dwarf Star

Astronomers using the TRAPPIST telescope at ESO's La Silla Observatory have discovered three planets orbiting an ultracool dwarf star just 40 light-years from Earth.


Effects of Mg/Si on Exoplanetary Refractory Oxygen Budget

Effects of Mg/Si on Exoplanetary Refractory Oxygen Budget

Solar photospheric abundances of refractory elements mirror the Earth's to within ~10 mol% when normalized to the dominant terrestrial planet-forming elements Mg, Si and Fe. This allows for the adoption of Solar composition as an order-of-magnitude proxy for Earth's.


Hiding in the Sunshine: The Search for Other Earths

Hiding in the Sunshine: The Search for Other Earths

We humans might not be the only ones to ponder our place in the universe. If intelligent aliens do roam the cosmos, they too might ask a question that has gripped humans for centuries: Are we alone?


Giant Planets in the Habitable Zone

Giant Planets in the Habitable Zone

We report the discovery of three new substellar companions to solar-type stars, HD191806, HD214823, and HD221585, based on radial velocity measurements obtained at the Haute-Provence Observatory.


Herschel Detects Oxygen in the beta Pictoris Debris Disk

Herschel Detects Oxygen in the beta Pictoris Debris Disk

The young star beta Pictoris is well known for its dusty debris disk, produced through the grinding down by collisions of planetesimals, kilometre-sized bodies in orbit around the star.


Habitability of Planets on Eccentric Orbits: Limits of the Mean Flux Approximation

Habitability of Planets on Eccentric Orbits: Limits of the Mean Flux Approximation

Contrary to Earth, which has a small orbital eccentricity, some exoplanets discovered in the insolation habitable zone (HZ) have high orbital eccentricities (e.g., up to an eccentricity of ∼0.97 for HD~20782~b).


Exoplanetary Atmospheres: Chemistry, Formation Conditions, and Habitability

Exoplanetary Atmospheres: Chemistry, Formation Conditions, and Habitability

Characterizing the atmospheres of extrasolar planets is the new frontier in exoplanetary science. The last two decades of exoplanet discoveries have revealed that exoplanets are very common and extremely diverse in their orbital and bulk properties.


The Imprecise Search for Habitability

The Imprecise Search for Habitability

As planets are being discovered around other stars by the thousands, several scientific disciplines that traditionally exist in parallel are converging, including astronomy, planetary science, and biochemistry.


The Fine Structure Constant and Habitable Planets

The Fine Structure Constant and Habitable Planets

We use the existence of habitable planets to impose anthropic requirements on the fine structure constant, α. To this effect, we present two considerations that restrict its value to be very near the one observed.


Impact of Stellar Rotation on Detectability of Habitable Planets Around M Dwarfs

Impact of Stellar Rotation on Detectability of Habitable Planets Around M Dwarfs

Stellar activity and rotation frustrate the detection of exoplanets through the radial velocity technique. This effect is particularly of concern for M dwarfs, which can remain magnetically active for billions of years.


Long-Term Stability of Planets in the α Centauri System

Long-Term Stability of Planets in the α Centauri System

We evaluate the extent of the regions within the α Centauri AB star system where small planets are able to orbit for billion-year timescales, and we calculate the positions on the sky plane where planets on stable orbits about either stellar component may appear.


An Earth-Like Planet in the GJ 832 System

An Earth-Like Planet in the GJ 832 System

Stability of planetary orbits around GJ 832 star system, which contains inner (GJ 832c) and outer (GJ 832b) planets, is investigated numerically and the detailed phase-space analysis are performed.



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