相关论文: Earth Similarity Index with two free parameters

Motivated by recent measurements of the free-floating planet mass function at terrestrial masses, we consider the possibility that the solar system may have captured a terrestrial planet early in its history. We show that $\sim 1.2$…

In this hypothesis article, we discuss the basic requirements of planetary environments where aerobe organisms can grow and survive, including atmospheric limitations of millimeter-to-meter-sized biological animal life based on physical…

The year 1996 will mark the initiation of a number of new space missions to the planet Mars from which we expect to obtain a rich set of data, including spacecraft radio tracking data. Anticipating these events, we have analyzed the…

In the last decade, about a dozen giant exoplanets have been directly imaged in the IR as companions to young stars. With photometry and spectroscopy of these planets in hand from new extreme coronagraphic instruments such as SPHERE at VLT…

One of the frontier research fields of exoplanetary science is the study of the composition and variability of exoplanetary atmospheres. This field is now moving from the gas giant planets towards the smaller and colder telluric planets,…

Planets and the stars they orbit are born from the same cloud of gas and dust, and the primordial compositions of rocky exoplanets have been assumed to have iron and refractory abundance ratios consistent with their host star. To test this…

We employ planetary evolution modeling to reproduce the MR distribution of the 198 so far detected planets with mass and radius measured to the <45% and <15% level, respectively, and less massive than 108Me. We simultaneously account for…

The search for a habitable extrasolar planet has long interested scientists, but only recently have the tools become available to search for such planets. In the past decades, the number of known extrasolar planets has ballooned into the…

To accurately characterize the planets a star may be hosting, stellar parameters must first be well-determined. $\tau$ Ceti is a nearby solar analog and often a target for exoplanet searches. Uncertainties in the observed rotational…

{\tau} Ceti (HD10700), a G8 dwarf with solar mass of 0.78, is a close (3.65 pc) sun-like star where 5 possibly terrestrial planet candidates (minimum masses of 2, 3.1, 3.5, 4.3, and 6.7 Earth masses) have recently been discovered. We report…

Sub-Neptune-sized exoplanets represent one of the most common types of planets in the Milky Way, yet many of their properties are unknown. Here, we present a prescription to adapt the capabilities of the stellar evolution toolkit Modules…

Measurements of the frequency with which short-period planets occur around main sequence stars allows a direct prediction of the number and types of such planets that will be amenable to characterization by high-contrast instruments on…

Molecular oxygen is a strong indicator of life on Earth, and may indicate biological processes on exoplanets too. Recent studies proposed that Earth-like O$_\mathrm{2}$ levels might be detectable on nearby exoplanets using high-resolution…

One of the main goals of the NASA's TESS (Transiting Exoplanet Survey Satellite) mission is the discovery of Earth-like planets around nearby M-dwarf stars. Here, we present the discovery and validation of three new short-period Earth-sized…

For the first time in human history the possibility of detecting and studying Earth-like planets is on the horizon. Terrestrial Planet Finder (TPF), with a launch date in the 2015 timeframe, is being planned by NASA to find and characterize…

The sample of exoplanets from the NASA Exoplanet Archive with equilibrium temperature less than 600 K and with low uncertainty for both mass and radius measurements is found to have a desert in the mass-radius distribution consistent with…

When a star is described as a spectral class G2V, we know its approximate mass, temperature, age, and size. At more than 5,700 exoplanets discovered, it is a natural developmental step to establish a classification for them, such as for…

We have investigated the information content in reflected-starlight spectra of exoplanets. We specify our analysis to Barnard's Star b candidate super-Earth, for which we assume a radius 0.6 times that of Neptune, an atmosphere dominated by…

Why are the terrestrial planets so different? Venus should be the most Earth-like of all our planetary neighbours. Its size, bulk composition and distance from the Sun are very similar to those of the Earth. Its original atmosphere was…

Searching for life elsewhere in the universe is one of the most highly prioritized pursuits in astronomy today. However, the ability to observe evidence of Earth-like life through biosignatures is limited by the number of planets in the…