by Astronomers have discovered not one but two planetary systems with sun-like stars at their hearts.
Both systems contain mini-Neptune planets and one hosts a huge “super-Jupiter” world, all of which are many times more massive than Earth. Studying these realms could lead to a better understanding of how planets form and evolve around sun-like stars, also known as “solar analogs.”
The discovery of the two systems was made using NASA’s Transiting Exoplanet Survey Satellite (TESS) and the 1.93-meter telescope at the Haute-Provence Observatory (OHP) in southern France. The OHP telescope has pedigree when it comes to detecting extrasolar planets or “exoplanets.” It is the instrument that astronomers Michel Mayor and Didier Queloz It was used to discover 51 Pegasi b in 1995, the first exoplanet discovered orbiting a Sun-like star.
These two newly discovered systems host at least three exoplanets, named TOI-1736 b, TOI-1736 c and TOI-2141 b, each of which is attached to a exoplanet catalog that has grown to contain more than 5,500 entries since the mid-1990s.
“We report the detection and characterization of two planetary systems around the solar analogs TOI-1736 and TOI-2141 using TESS photometry data and spectroscopic data obtained with the SOPHIE instrument on the OHP’s 1.93 m telescope.” Paris Institute of Astrophysics wrote the scientist and lead author of the research, Guillaume Hébrard, with his co-authors in an article published in the journal Astronomy and Astrophysics. “We performed detailed spectroscopic analysis of these systems to obtain the precise radial velocities and physical properties of their host stars.”
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TOI-2141: A planetary system around an old star
The first planetary system discovered by Hébrard and his colleagues is TOI-2141, located about 250 light years away. Land and centered around a star that is comparable in size to Sun but it seems to be older than our star. We know this because TOI-2141’s star lacks chemical elements heavier than hydrogen and helium, known as “metals.” On the contrary, our Sun, 4.6 billion years old, is highly enriched in this type of metals. With some calculations, the team realized that the proportion of metals suggests that the newly studied star is around 7.5 billion years old.
The planet in this system, TOI-2141 b, was detected while crossing or “transiting” the face of its parent star, blocking some of the light coming from the star and therefore causing the star to dim from the point scope of the telescope. The team was able to determine that this planet is about three times the width of Earth, with a mass about 24 times that of our planet, making it a mini-Neptune exoplanet.
TOI-2141 b is located at a distance of about 20 million kilometers from its star, about 13% of the distance between the Earth and the Sun. This means that mini-Neptune completes an orbit about once every 18.3 Earth days, and this proximity also raises its temperature to around 840 degrees Fahrenheit (450 degrees Celsius).
The density of this planet and the high temperature of its surface indicate that it is formed by a rocky core surrounded by an atmosphere full of water vapor. So far, TOI-2141 b is the only planet found in the TOI-2141 system, but the team has not yet ruled out the possibility of other smaller planets orbiting the Sun-like star.
And, as impressive as this first system is, the second planetary system discovered by the team is something a little more unique.
The exotic TOI-1736
Located around 290 Light years From Earth, TOI-1736 is somewhat more exotic than TOI-2141. At first glance, its main star is nothing special: it is about the same age as the Sun, about 4.9 billion years old, about the same size as the Sun, only 15% larger than our star, and even about the same temperature.
However, the TOI-1736 system is extraordinary because its main star has a second, smaller companion star, making it a binary system.
Massive stars They are commonly found in binary systems, but this dual lifestyle is rarer in Sun-sized stars, and only about 44% of solar analogues are found with a companion. What’s even stranger is that TOI-1736’s companion star is so distant from the main star that the exoplanets the team found actually only orbit the system’s main star.
More specifically, Hébrard and his colleagues found two planets in this exotic star system. The first is another mini-Neptune with a width approximately 2.5 times that of Earth and a mass 13 times that of our planet. This planet, TOI-1736 b, orbits its star at a distance of just 6.5 million miles, which is about 7% of the distance between the Earth and the Sun, and completes one orbit in about 7.1 days. terrestrial. TOI-1736’s proximity to its star means it has a temperature of about 1,500 degrees Fahrenheit (800 degrees Celsius).
The second planet in the system, TOI-1736 c, is the so-called “super-Jupiter” with a mass around 2,800 times that of Earth and a width around 9 times that of Earth. Jupitermaking it a staggering 99 times wider than Earth.
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TOI-1736 c is located about 200 million kilometers from its star, about 1.3 times the distance between the Earth and the Sun, meaning it completes an orbit about once every 570 Earth days. This distance also places the planet in the living area from its parent star: the distance at which water can exist in a liquid state. TOI-1736c is a giant gasso it lacks a solid surface, but could have moons with atmospheres that allow liquid water to exist on their surfaces, perhaps making them habitable?
The answers to such questions will come time; Meanwhile, the team is focusing on some signs of a third planet that appears to exist around TOI-1736. They soon intend to investigate this clue with the OHP’s SOPHIE spectrograph.
