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Data will characterize planetary atmosphere models



Discovered a super-Earth that can be used to test planetary atmospheric models

The moment of the virtual journey, with superimposed astronomical data. Credit: RenderArea

In the past 25 years, astronomers have discovered various exoplanets made of rocks, ice, and natural gas due to the construction of astronomical instruments designed specifically for searching for planets. Moreover, by using a combination of different observation techniques, they have been able to determine a large number of masses, sizes, and planet densities, which helps them estimate their internal composition and increase the number of planets found outside the planet. Solar system.

However, it is very difficult to study the atmosphere of rocky planets, which will enable them to fully characterize exoplanets similar to the Earth. Therefore, the atmospheric model of the rocky planet is still untested.

Therefore, it is interesting that the Canarias astronomers (Calar Alto uses near-infrared and optical Eschel spectrometers to detect exogenous M dwarfs with high resolution) are a consortium formed by the Canarias Institute of Astronomy (IAC) A study led by astronomer Trifon Trifonov of the Max Planck Institute for Astronomy in Heidelberg, Germany published a study about the orbit near the nearby red dwarf star Gliese 486 A hot super-Earth was discovered on Earth, only 26 light-years away from the planet. sun.

To this end, the scientists used a combination of transmission photometry and radial velocity spectroscopy, and used MuSCAT2 on the 1

.52m Carlos Sanchez telescope at the Ted Observatory (multi-color simultaneous cameras studied the atmosphere of exoplanets) ) Make observations. .The results of this study have been published in the journal science.







The virtual journey to Gliese 486b begins with its position in the night sky. After focusing on the parent star Gliese 486b, the film describes the measurement results. Finally, we fly to the exoplanet Gliese 486b and explore its possible surface, which may be similar to Venus, with a dry surface and hot lava flows. Credit: RenderArea

The planet they discovered is called Gliese 486b, and its mass is 2.8 times that of the Earth, which is only 30% larger. Enric Pallé, an IAC researcher and co-author of the paper, explained: “Calculating the average density based on the mass and radius measurements, we infer that its composition is similar to that of Venus or the Earth, with a metallic core inside. .”article.

Gliese 486b orbits its host star 2.5 million kilometers in a circular path every 1.5 days. Despite being very close to the star, the planet may have retained part of its original atmosphere (stars are much cooler than our sun), so it is an ideal telescope for more detailed observations in space and on the ground for the next generation.

Discovered a super-Earth that can be used to test planetary atmospheric models

The graph provides an estimate of the internal composition of the selected exoplanet based on its mass and radius (in Earth units). The red dot represents Gliese 486b, and the orange symbol represents planets around cool stars like Gliese 486. Gray dots indicate planets surrounded by hotter stars. The color curve represents the theoretical mass radius relationship of 700 K pure water (blue), enstatite (orange), earth (green) and pure iron (red). In contrast, the figure also highlights Venus and the Earth. Image source: Trifonov et al./MPIA Graphics Department.

For Trifonov, “The fact that the planet is too close to the sun is exciting because powerful telescopes such as the James Webb Space Telescope and ELT (Extra Large Telescope) under construction can be used to study it in more detail.”

Gliese 486b takes the same time to rotate along its axis as it takes to rotate around its host star, so it always has the same side facing the star. Although Gris 486 is weaker and cooler than the sun, the radiation is so strong that the planet’s surface is heated to at least 700K (about 430 degrees Celsius). Therefore, the surface of Gliese 486b may be more like the surface of Venus, while the surface of the Earth is hotter, with dry terrain, and burning lava rivers. However, unlike Venus, the atmosphere of Gris 486b may be thin.

Discovered a super-Earth that can be used to test planetary atmospheric models

This image shows the orbit of a planetary, rocky exoplanet like Gliese 486b orbiting its host star. During transportation, the planets eclipse the stellar disk. At the same time, a small portion of starlight passes through the planet’s atmosphere. As Gliese 486b continues to orbit, certain parts of the illuminated hemisphere will show up in phase until the planet disappears behind the star. Image source: MPIA Graphics Department.

Calculations using existing planetary atmospheric models can be consistent with hot surface and thin atmosphere scenarios, because stellar radiation will evaporate the atmosphere, and planetary gravity will suppress the atmosphere. Today, it is difficult to determine the balance between the two donations.

Astrobiology Center researcher José Antonio Caballero explained: “The discovery of Gliese 486b is really lucky. If the temperature rises to about 100 degrees, its entire surface will be lava, and its atmosphere Will be evaporated rocks.” CAB, CSIC-INTA) and co-author of the article. “On the other hand, if the temperature of Gliese 486b is about 100 degrees lower, then it is not suitable for follow-up observation.”

Discovered a super-Earth that can be used to test planetary atmospheric models

Artist’s impression of the atmosphere of Gliese 486b. Credit: RenderArea

Future planned observations by the CARMENES team will attempt to determine its orbital inclination, which will allow Gliese 486b to cross the line of sight between us and the surface of the star, obscure some of its light, and create a so-called transit.

They will also use emission spectroscopy to perform spectroscopic measurements, before disappearing in the orbit of the star Gliese 486b, when the hemisphere illuminated by the star is visible as the phase of the planet (similar to our moon phase). The observed spectrum will contain information about the condition of the hot surface of the planet being illuminated.

Trifonov admits: “We can’t wait until the new telescopes come out.” “The results we might get with them will help us better understand the atmospheres of rocky planets, their extensions, their extremely high densities, their composition, and their composition. The impact on the distribution of energy around the planet.

  • Discovered a super-Earth that can be used to test planetary atmospheric models

    The artistic sense of the newly discovered and popular super-earth Gliese 486b. The temperature of Gliese 486b is about 700 Kelvin (430°C) and there may be atmosphere. Credit: RenderArea

  • MAROON-X begins to explore exoplanets

    The color 2D spectrum of the star Gliese 486 observed with MAROON-X. These two spectra come from the two camera arms of MAROON-X. Each spectrum covers the 500-670 nm wavelength range, and the color coding corresponds to how the human eye perceives colors. Image source: International Gemini Observatory/NOIRLab/NSF/AURA/A.Sai Fakht

The CARMENES project consists of 11 research institutions in Spain and Germany. Its purpose is to use the spectrometer on the 3.5 m telescope of the Calar Alto Observatory to monitor 350 red dwarfs to find planets like the Earth (Spain). This study also used spectral measurements to infer the quality of Gliese 486b. The MAROON-X instrument was used to observe on Gemini North (8.1m) in the United States. The archived data came from the Keck 10 m telescope in the United States and the ESO 3.6 m telescope in Chile.

The photometric observation comes from NASA’s TESS (Transitional Exoplanet Survey Satellite) space observatory. The data is the basis for obtaining the planet’s radius. The data comes from the MuSCAT2 instrument on the 1.52m Carlos Sánchez telescope at the Ted Observatory (Spain). Chile’s LCOGT (Las Cumbres Observing Global Telescope) and so on.


Super-Earth discovered orbiting in nearby red dwarf stars


More information:
T. Trifonov et al. Transit rocky exoplanets suitable for atmospheric surveys nearby. science (2021). science.sciencemag.org/cgi/doi…1126 / science.abd7645

Provided by the Canarias Space Institute



Citation: Discovery of Super-Earth: Data will represent the planetary atmosphere model retrieved from https://phys.org/news/2021-03-super-earth-planetary-atmosphere.html on March 4, 2021 (March 4, 2021 Day) characteristics.

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