Astronomers have discovered not one but two planetary systems with sun-like stars at their hearts.
Both of these systems contain mini-Neptune planets, and one hosts a massive “super-Jupiter” world, each many times larger than Earth. Studying the realms can 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 a superior pedigree in detecting extrasolar planets, or “exoplanets.” This is the instrument used by astronomers. Michel Mayor and Didier Queloz He discovered 51 Pegasi b in 1995; It was the first exoplanet to orbit 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 joined by a planet. outer planet The catalog has grown to include more than 5,500 entries since the mid-1990s.
“We report the detection and characterization of two planetary systems around solar analogs TOI-1736 and TOI-2141 using TESS photometry data and spectroscopic data obtained with the SOPHIE instrument on the 1.93 m telescope at OHP.” Paris Astrophysics Institute scientist and lead study author Guillaume Hébrard wrote with his co-authors in an article published in the journal: Astronomy and Astrophysics. “We carried out a detailed spectroscopic analysis of these systems to obtain the precise radial velocities and physical properties of the host stars.”
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TOI-2141: Planetary system around an ancient star
The first planetary system discovered by Hébrard and his colleagues was TOI-2141, located approximately 250 light-years away. Soil and is centered around a star comparable in size to itself. Sun but it looks 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 other hand, our 4.6 billion-year-old sun is very rich in such metals. The team realized that through some calculations, the metal ratio indicated that the newly examined star was approximately 7.5 billion years old.
The planet in this system, TOI-2141 b, was detected passing or ‘transiting’ across the face of its parent star; It blocked some of the light from the star, thus causing the star to darken from the old spot of the telescope. The team was able to determine that this planet is approximately three times larger than Earth and has a mass approximately 24 times that of our planet.Neptune exoplanet
TOI-2141 b is located about 12 million miles from its star; this is about 13% of the distance between the Earth and the sun. This means that mini-Neptune completes an orbit roughly every 18.3 Earth days, and this close proximity also sends its temperature to around 840 degrees Fahrenheit (450 degrees Celsius).
This planet’s density and warm surface temperature indicate that it consists of a rocky core surrounded by an atmosphere filled with 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 minor planets orbiting the sun-like star.
And as impressive as that first system was, the second planetary system the team discovered is something a little more unique.
Exotic TOI-1736
around 290 light years TOI-1736 is slightly more exotic than TOI-2141 from Earth. At first glance, its main star is unremarkable; It is approximately 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 the same temperature.
But the TOI-1736 system is extraordinary because its parent star second, smaller companion star, making this a binary system.
Bodied stars is common in binary systems, but this dual lifestyle is rarer for sun-sized stars; Only 44% of solar analogues are found with a companion. Even stranger is that TOI-1736’s companion star is so far from the parent star that the exoplanets the team found actually orbit only the system’s parent star.
More specifically, Hébrard and his colleagues found two planets in this exotic star system. The first is another mini-Neptune, about 2.5 times the width of Earth and a mass 13 times greater than our planet’s. This planet, named TOI-1736 b, orbits its star at a distance of only 6.5 million miles, or about 7% of the distance between the Earth and the sun, and completes its orbit in about 7.1 Earth days. TOI-1736 b’s close proximity to its star means its temperature is about 1,500 degrees Fahrenheit (800 degrees Celsius).
The second planet of the system, TOI-1736 c, is a planet called a “super Jupiter” that is about 2,800 times the mass of Earth and about 9 times as wide. JupiterThis makes it 99 times wider than Earth.
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TOI-1736 c is located approximately 128 million miles from its star; this is about 1.3 times the distance between Earth and the sun, meaning it completes its orbit roughly every 570 Earth days. This distance also covers the planet habitable zone distance from its parent star – where water can exist in liquid form. TOI-1736 c a gas gianti.e. they may have moons that do not have a solid surface, but have atmospheres that allow liquid water to exist on their surfaces – perhaps making them habitable?
Answers to such questions will come time; Meanwhile, the team is focusing on some signs of a third planet located around TOI-1736. They plan to investigate this clue soon with the SOPHIE spectrograph at OHP.