- 3952 - EXOPLANET DISCOVERIES - more planets. An Earth-size exoplanet spotted just 72 light-years away. Researchers hope to discover more exoplanets in this K2-415 system.
------------ 3952 - EXOPLANET DISCOVERIES - more planets
- K2-415b, as
the newly discovered world has been named, orbits the nearby red dwarf star
K2-415. Researchers identified the exoplanet in the data of NASA's now-defunct
Kepler space telescope, its secondary mission K2, and its successor, the
Transiting Exoplanet Survey Satellite.
-
- While
K2-415b is not the closest known exoplanet to Earth, it is, on a cosmic scale,
one of our close neighbors. The K2-415
system is unique in that K2-415 is one of the coolest, or lowest-mass, stars
known to host an exoplanet. There are
only four stars cooler than K2-415 that are known to host at least one
exoplanet, including the famous TRAPPIST-1, which has seven known exoplanets.
-
- One
motivation for investigating the planets around such low-mass stars is to
understand and clarify whether those planets form and evolve just like the
planets around solar-type stars.
-
- Solar-type
stars are stars akin to our sun. Red dwarf stars (also known as M-dwarfs), on
the other hand, are far cooler and much smaller. K2-415 is thought to have a
surface temperature of about 5,250 degrees Fahrenheit, compared to our sun's
9,900 degrees F, with a diameter of 0.2 solar radii and a mass just 0.16 times
that of the sun.
-
- K2-415b is
not in the habitable zone of its star, or the distance from a star at which
liquid water can exist on a world's surface. The exoplanet is extremely close
to K2-415, so close that it only takes about four Earth days to complete an
orbit.
-
- But, there is a possibility that there is another
planet lurking in the system that sits inside the habitable zone. Astronomers will study K2-415b further,
determining its mass and internal structure. Preliminary estimates peg the exoplanet
as about three times more massive than Earth, despite having a radius just
1.015 times that of Earth.
-
- So far, only
one transiting planet was found in the system, but this does not necessarily mean the system is a 'single'
one. Further radial velocity
observations, as well as photometric monitoring, will be able to constrain the
presence of outer planets in this system.
-
- James Webb
Space Telescope finds a 'hot Jupiter' exoplanet that defies expectations. The exoplanet “Smertrios” has a surprising
abundance of heavy elements in its atmosphere.
-
- The
atmospheres of gas giant planets across the Milky Way galaxy can be very
different from those in our solar system, the James Webb Space Telescope has
found. Observations of the distant
exoplanet HD149026b, also known as Smertrios, revealed that the planet's
atmosphere is rich in what scientists call heavy elements, essentially anything
other than hydrogen and helium. In Smertrios' atmosphere, they detected high
concentrations of carbon and oxygen.
-
- The results
have taken astronomers by surprise. In gas giant planets of our solar system,
such as Jupiter, Saturn, Uranus and Neptune, scientists see a clear correlation
between the planet's mass and the amount of heavy elements in the atmosphere.
The more massive the planet, the lower the concentrations of these elements in
its atmosphere.
-
- The giant
planets of our solar system exhibit a nearly perfect correlation between both
overall composition and atmospheric composition and mass.
-
- Astronomers
have seen more diverse atmospheric compositions in gas giant exoplanets
previously, but the composition of the atmosphere of HD149026b is off the
charts. The planet is the mass of
Saturn, but its atmosphere seems to have as much as 27 times the amount of
heavy elements relative to its hydrogen and helium that we find in Saturn.
-
- HD149026b,
or Smertrios, is a Jupiter-like planet that orbits extremely close to its
parent star. In the case of Smertrios, this distance is so short that the
planet's year lasts only three Earth days. As a result of this close proximity
to the star, temperatures in Smertrios' atmosphere reach a scorching 2,700
degrees Fahrenheit, which is three times higher than the surface temperature of
the solar system's hottest planet, Venus.
-
- It appears
that every giant planet is different, and we're starting to see those
differences thanks to JWST. The
research has determined how many molecules there are relative to the primary
component of the gas, which is hydrogen, the most common element in the
universe. That tells us quite a lot about how this planet formed.
-
- By
measuring the atmospheric composition of a planet, scientists can get an
insight into the chemistry of its parent star and the material from which it
formed millions or billions of years ago.
-
- The
planetary disk that gave rise to Smertrios must have had much more carbon
compared to oxygen than the disk that birthed our solar system. The origin of
this diversity is a fundamental mystery in our understanding of planet formation.
-
- Further
atmospheric observations of extrasolar planets with JWST will quantify this
diversity better and yield constraints on more complex trends that might exist.
We have shown definitively that the atmospheric compositions of giant
extrasolar planets do not follow the same trend that is so clear in the solar
system planets.
-
April 9, 2023 EXOPLANET DISCOVERIES
- more planets 3952
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