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| Two planets of the Venus sphere orbiting nearby red dwarfs |
Two planets of the Venus sphere orbiting nearby red dwarfs. Astronomers discovered and validated two small exoplanets that orbit near the red dwarf stars TOI-1266. Artist's impression of the TOI-1266 planetary system. TOI-1266, also known as TIC 467179528 and 2MASS J13115955 + 6550017, is an M2-type dwarf star in the Draco planetarium about 118 light-years away.
The star is less than half the mass and size of the Sun and is approximately 8 billion years old. It houses at least two planets, TOI-1266b and c, which are closer to the star than our planet Sun. The inner planet is 2.6 times larger than Earth and belongs to a class of exoplanets called Mini-Neptune.
It orbits the TOI-1266 once every 10.9 days at a distance of only 10.7 AU (astronomical units). The orbit of the outer planet is 18.8 days and is 0.1 AU from the star. The alien world is 1.67 times the size of Earth and lives in Faulton Gap (also known as the Radius Valley), the transition zone between rocky planets and gas giants.
"If TOI-1266c has a rocky composition, it could be a super Venus," said astronomer Gudmundur Stephenson and colleagues at Princeton University. TOI-1266b and c receive 4.7 and 2.4 times more sun than Tierra del Sol, respectively. Both planets are in the so-called Venus zone, a series of stellar distances where there is an early Earth-like atmosphere that can experience a runaway greenhouse effect that turns it into an atmosphere like Venus.
"Detailed characterization of systems in the Venus region, including large-scale and atmospheric compositions, will improve our understanding of the limits of habitable environments," the astronomers said. Dr. Stephenson and his co-authors detected TOI-1266b and c using NASA's Exoplanet in Transit Study Satellite (TESS).
He then took 0.43m Richard S. at Hobart and William Smith Colleges. Planetary transits observed using the ARCTIC Imager at the Perkin Telescope and the 3.5-meter ARC Telescope at the Apache Point Observatory. They also obtained and analyzed the high-resolution spectra of the TOI-1266 with the Habitable Zone Planet Finder to impose upper limits on the mass of both planets and obtain accurate stellar parameters.
The researchers said
"We obtained a higher mass range of 15.9 and 6.4 land masses with 95% confidence for planets TOI-1266b and c, respectively." Our current mass has indicated that TOI-1266c may have a predominantly non-rock composition, indicating that the planet is rich in water and / or can maintain an atmosphere despite its small size. An article reporting this discovery will be published in one of the AAS magazines and will be available online.
The nearby red dwarf houses two super-Earth-sized exoplanets, one in its habitable zone. ' An international team of astronomers discovered that a little-known exoplanet called K2-18b may be a smaller version of Earth, and also revealed that the planet has a giant neighbor, K2-18c. This artist's concept shows two exoplanets from the super Earth, K2–18b and c, orbiting the red dwarf star 2–2–18.
"Being able to measure the mass and density of K2-18 was tremendous, but fortunate and just as exciting to find a new exoplanet," Ryan Cloitier, PhD student at the University of Toronto and the Research Institute at Montanetal University Exoplanets indicated in.
Both exoplanets are K2-18 (also known as EPIC 201912552), a red dwarf star located about 111 light years away in the constellation Leo. When K2-18b was first discovered in 2015, it was found to orbit within the star's habitable zone, making it an ideal candidate for liquid surface water.
To find out if the planet is an enlarged version of Earth (mostly rock), or a reduced version of Neptune (mostly gas), Clotier and his co-authors first had to find out the mass of the planet.
"If you can get mass and radius, you can measure the apparent density of the planet and it can tell you what most of the planet is made of," Clotier said.
Astronomers discovered that the mass of K2-18b is approximately 8 times greater than that of Earth. It has an apparent density of 3.7 g / cm3 and is a rocky planet with a small, but Earth-like, gaseous atmosphere, or a mostly aquatic planet with a thick layer of ice above it. "It was during the observation of the K2-18b data that we noticed something unusual," she said.
In addition to a sign that occurs every 39 days since the K2-18 rotation, and a space from the K2-18b orbit every 33 days, they saw a different signal every 9 days. "When we first threw the data on the table, we were trying to figure out what it was," said Clottier.
"You have to make sure there is not only noise, and you have to do a careful analysis to verify it, but seeing that the initial signal was a good signal, there was another planet." The new alien world, K2-18c, is also a super Earth, about 7.5 times its mass.
The planet is closer to its star than K2-18b, and it is probably too hot to be in the habitable zone. "It wasn't an Eureka! Moment because we still had to go through a list of things to verify the data," said Cloutier. "Once all the boxes were checked, it sank, wow, this is actually a planet."
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| The nearby red dwarf houses two super-Earth-sized exoplanets |
The nearby red dwarf houses two super-Earth-sized exoplanets, one in its habitable zone. ' An international team of astronomers discovered that a little-known exoplanet called K2-18b may be a smaller version of Earth, and also revealed that the planet has a giant neighbor, K2-18c. This artist's concept shows two exoplanets from the super Earth, K2–18b and c, orbiting the red dwarf star 2–2–18.
"Being able to measure the mass and density of K2-18 was tremendous, but fortunate and just as exciting to find a new exoplanet," Ryan Cloitier, PhD student at the University of Toronto and the Research Institute at Montanetal University Exoplanets indicated in.
Both exoplanets are K2-18 (also known as EPIC 201912552), a red dwarf star located about 111 light years away in the constellation Leo. When K2-18b was first discovered in 2015, it was found to orbit within the star's habitable zone, making it an ideal candidate for liquid surface water.
To find out if the planet is an enlarged version of Earth (mostly rock), or a reduced version of Neptune (mostly gas), Clotier and his co-authors first had to find out the mass of the planet.
"If you can get mass and radius, you can measure the apparent density of the planet and it can tell you what most of the planet is made of," Clotier said.
Astronomers discovered that the mass of K2-18b is approximately 8 times greater than that of Earth. It has an apparent density of 3.7 g / cm3 and is a rocky planet with a small, but Earth-like, gaseous atmosphere, or a mostly aquatic planet with a thick layer of ice above it. "It was during the observation of the K2-18b data that we noticed something unusual," she said.
In addition to a sign that occurs every 39 days since the K2-18 rotation, and a space from the K2-18b orbit every 33 days, they saw a different signal every 9 days. "When we first threw the data on the table, we were trying to figure out what it was," said Clottier.
"You have to make sure there is not only noise, and you have to do a careful analysis to verify it, but seeing that the initial signal was a good signal, there was another planet." The new alien world, K2-18c, is also a super Earth, about 7.5 times its mass.
The planet is closer to its star than K2-18b, and it is probably too hot to be in the habitable zone. "It wasn't an Eureka! Moment because we still had to go through a list of things to verify the data," said Cloutier. "Once all the boxes were checked, it sank, wow, this is actually a planet."
An article describing the discovery will appear in the Journal of Astronomy and Astrophysics and is now available online.
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