Researchers visualized a solar system with up to seven exoplanets around TOI-1136 and used advanced methodologies to precisely measure their properties; This could significantly impact planet formation theories. A newly discovered solar system with six confirmed exoplanets and a possible seventh planet is increasing astronomers’ knowledge of planet formation and evolution. Drawing on an arsenal of observatories and instruments around the world, a team led by researchers from the University of California, Irvine has compiled the most accurate measurements of exoplanet masses, orbital properties and atmospheric properties.

In the article published on January 29 Astronomy Magazine , researchers shared results from the TESS-Keck Survey, which provides a detailed description of exoplanets orbiting TOI-1136, a dwarf star more than 270 light-years distant in the Milky Way galaxy. The research builds on the team’s first observations of stars and exoplanets in 2019, using data from NASA’s Transiting Exoplanet Survey Satellite (TESS). This project provided the first estimate of the mass of exoplanets by measuring fluctuations in transit times, a measure of the gravitational force that orbiting planets exert on each other.

Advanced methods of exoplanet analysis

For the latest research, scientists combined TTV data with analysis of the star’s radial velocity. Using the Automated Planet Finder telescope at the Leake Observatory on Mount Hamilton in California and the High Resolution Echelle Spectrometer at the W. M. Keck Observatory on Mauna Kea in Hawaii, they were able to detect subtle changes in the stars’ motion across the red and blue. Changing the Doppler effect helped them determine the mass of the planet with unprecedented accuracy.

To obtain such precise information about the planets of this solar system, the team created computer models using hundreds of radial velocity measurements superimposed on TTV data. Lead author Corey Bird, UCI Ph.D. The combination of these two types of readings provides more information about the system than ever before, the physics major said.

“It took a lot of trial and error, but we were very pleased with our results after developing one of the most complex planetary system models in the exoplanet literature to date,” said Byrd.

Knowledge and future research directions

The large number of planets is one of the factors that inspired the team of astronomers to investigate further, according to co-author Paul Robertson, a professor of physics and astronomy at UCI.

“We found TOI-1136 to be very advantageous from a research perspective because when a system has more than one exoplanet, we can control the impact of the planet’s evolution relative to its host star, which helps us focus on the individual physical mechanisms that give rise to these planets and the properties they have.” said.

Robertson added that when astronomers try to compare planets in separate solar systems, there are many variables that can vary depending on the different properties of the stars and their locations in different parts of the galaxy. Looking at exoplanets in the same system allows studying planets with a similar history, he said.

By stellar standards, TOI-1136 is young, only 700 million years old, another feature that appeals to exoplanet hunters. Robertson said working with young stars was “difficult and special” because they were so active. Magnetism, sunspots, and solar flares are more common and intense at this stage of the star’s development, and the resulting radiation explodes and forms planets, affecting their atmospheres.

Confirmed exoplanets TOI-1136 b through TOI-1136 g TOI-1136 are classified by experts as “sub-Neptunes”. The smallest of these is more than twice the radius of the Earth, while the others are four times the radius of the Earth, comparable in size to Uranus and Neptune, Robertson said.

According to the study, all these planets orbit TOI-1136 in less than the 88 days it takes for Mercury to reach Earth orbit. “We’re squeezing the entire solar system into a region around a star small enough that our entire planetary system is excluded,” Robertson said.

“They are strange planets to us because there is nothing like them in our solar system,” said co-author Rae Holcomb, UCI Ph.D. candidate in physics “But as we investigate other planetary systems further, we see that they may be the most common type of planet in the galaxy.”

Another strange component of this solar system is the possible, as yet unconfirmed, existence of a seventh planet. Researchers have found some evidence of another resonant force in the system. Robertson explained that when planets orbit close together, they can gravitationally pull on each other.

“When you hear a chord played on the piano and it sounds pleasing to you, it’s because there’s a resonance or even an interval between the notes you hear,” he said. “The rotation periods of these planets are positioned in the same way. When the outer planets are in resonance, the tugs move in the same direction each time. This can have a destabilizing effect or, in special cases, cause orbits to form.” More stable”.

Robertson noted that the survey does not answer all of his team’s questions about exoplanets in this system, but it encourages researchers to seek additional information, especially about the composition of planetary atmospheres. This line of research is best approached with the advanced spectroscopy capabilities of NASA’s James Webb Space Telescope, he said.

“I am proud that UCO’s Lick Observatory and Keck Observatory were involved in the identification of a truly important system,” said Matthew Shetrone, deputy director of the UC Observatory. “Having so many medium-sized planets in a single system really allows us to test formation scenarios. I really want to learn more about these planets! Could we find a world of molten rock, a world of water, and a world of ice in the same solar system?” It’s almost like science fiction.”