Exoplanet

Ott 5 2019

Water vapor in the atmosphere of an inhabitable rocky planet

There’s no shortage of water in the universe. Water molecules have even been found in the cold interstellar medium. After hydrogen, water is the second most abundant substance in the atmosphere of hot gas planets. Neptune, Uranus, and their siblings in space are not called ice giants for no reason – they also contain a large amount of water ice. On rocky planets, water could be a sign of good conditions for life. This, however, would also depend on where the water is located. Researchers already think that some planets have large quantities of water due to their densities.…

The weather for HR 8799 e: 1000 degrees Celsius with clouds of iron and silicate dust

Astrophysics

Apr 9 2019

The weather for HR 8799 e: 1000 degrees Celsius with clouds of iron and silicate dust

HR 8799 e is a rather inhospitable place. The celestial body discovered in 2010 and orbiting the 30-million-year-young star HR 8799 at a distance of 129 light-years from Earth is a gas giant similar to Jupiter. But its host star shines nearly five times brighter than our Sun, creating a significantly hotter atmosphere for HR 8799’s innermost planet (despite the “e,” HR 8799 e is the closest planet to its host star) than Jupiter. That is quite astonishing because at approximately 14.5 AU, HR 8799 e is almost five times farther from its host star than Jupiter is from…

Space

Gen 10 2019

A sapphire- or ruby-like planet?

55 Cancri e, HD219134 b, and WASP-47 e are three rocky planets – and they have something else in common: they might belong to a new class of super-Earths, according to arguments laid out by scientists from the University of Zurich and the University of Cambridge in a new paper. The astronomers looked at how planets are formed in protoplanetary disks. If they are formed, like the Earth, at a reasonable distance from their central star, then heavy elements, such as iron, magnesium, and silicon, condense. If, however, the protoplanet has an orbit that is very close to its…

Neptunes and super-Earths are the most common types of exoplanets

Space

Gen 7 2019

Neptunes and super-Earths are the most common types of exoplanets

With the help of the ALMA radio telescope, astronomers have taken a closer look at a series of protoplanetary disks around young stars in the Taurus Molecular Cloud, a region 430 light-years from Earth, in which many stars are currently being born. The researchers examined 32 protoplanetary disks; twelve of these disks have a structure with rings and gaps. (altro…)

A better weather report for the seven worlds of the Trappist system

Space

Dic 5 2018

A better weather report for the seven worlds of the Trappist system

The red dwarf Trappist-1 is orbited by seven rocky planets. For a long time, this large number of planets has made it seem likely that at least one of them might be habitable. Now, in an article in the Astrophysical Journal, astronomers have reported on their results from calculations using previously known data to produce more precise atmospheric models for the seven worlds. (altro…)

Epsilon Indi C: a moon as massive as 70 Jupiters?

Space

Nov 20 2018

Epsilon Indi C: a moon as massive as 70 Jupiters?

The star Epsilon Indi is just barely visible with the naked eye in the southern sky. It is at a distance of 11.8 light-years from the Earth and has approximately the same size as the Sun but is somewhat older. It has also turned the usual classification of star, planet, and moon upside down. This is because what we see is only Epsilon Indi A, but the star is orbited by a brown dwarf with a mass of 75 Jupiters and this brown dwarf has, in turn, a companion with a mass of 70 Jupiters. (altro…)

Rocky with a hint of hydrogen: what’s a good recipe for a planet?

Life

Ott 17 2018

Rocky with a hint of hydrogen: what’s a good recipe for a planet?

Rocky planets are rather small and gas giants are large – that’s one hypothesis you might come up with if you look at our Solar System. But is that true always and everywhere? Is our own system an example of the rule or an exception to the rule? Astronomers have now found more than 3700 exoplanets, but very little is known about their composition. At most the radius and mass are known. But even if the size and mass are known, it is still very difficult to say whether the exoplanet has, in fact, a large, but thanks to…

Space

Ott 6 2018

Exoplanets have pretty moons too

Nobody really believes that our Solar System is the only one with moons. But the existence of moons in other star systems has only been a hypothesis up until now. So-called exomoons are particularly difficult to find, because they are smaller than their host planets (which is, of course, in their nature) and they follow complicated paths due to their orbits around their planets and, in turn, around their stars. Such objects are usually identified by measuring the occultation caused when they pass in front of their star (transit method). Nevertheless, the Hubble Space Telescope has now finally found…