Radiating exoplanets discovered in ‘perfect tidal storm’

Could tidal forces cause exoplanet surfaces to radiate heat?This is an accepted study astronomical magazine An international team of researchers hopes to use data collected from ground-based instruments to confirm the presence of a second exoplanet in the exoplanet system HD 104067, and to identify an additional exoplanet using NASA’s Transiting Exoplanet Survey Satellite (TESS) mission planet.The research is available at arXiv Preprint server.

Compared with the other two, the orbit of this exoplanet is located in the innermost one. What makes it unique is that the tidal forces exhibited by the outer two exoplanets may cause surface radiation of the candidate exoplanet, and its surface With temperatures reaching 2,300 degrees Celsius (4,200 degrees Fahrenheit), researchers called it a “perfect tidal storm.”

Universe Today discusses this remarkable study with Dr. Stephen Cain, professor of planetary astrophysics at UC Riverside and lead author of the study, discussing the motivations behind the study, the significant results, the “tidal storm” aspect The significance of the following studies, as well as the impact of this system on the study of other exoplanetary systems. So, what was the motivation behind this study?

“This star (HD 104067) is a star known to host a massive planet in a 55-day orbit, and I have long been fascinated by known systems,” Dr. Kane told Universe Today. “When TESS detected a possible transiting Earth-sized planet (TOI-6713.01) in a 2.2-day orbit, I decided to examine the system further. We collected all the RV data and found that there was another planet in the 13-day orbit. A (Uranus-mass) planet.

Dr. Kane’s history of exoplanet research covers numerous solar system architectures, particularly those containing highly eccentric exoplanets, as well as follow-up work after exoplanets have been confirmed within a system. Most recently, he was second author on a study that discussed modified system architecture in the HD 134606 system, where two new super-Earths were discovered.

In this latest study, Dr Kane and his colleagues used data from the High Accuracy Radial Velocity Planet Searcher (HARPS) and High Resolution Echelle Spectrometer (HIRES) ground-based instruments, as well as the aforementioned TESS mission, to identify two Characteristics and parameters of the parent star HD 105067 and the corresponding exoplanets orbiting it. But, as Dr. Kane mentioned, aside from the discovery of other exoplanets within the system, what are the most important results of this research?

Dr Kane told Universe Today, “The most surprising result of our work is that the dynamics of the system cause the system to experience large tidal effects on a 2.2-day period, similar to what Io experiences. But in this case Below, TOI-6713.01 experiences 10 million times more tidal energy than Io, producing 2,600K [2,300 degrees Celsius (4,200 degrees Fahrenheit)] surface temperature. This means the planet actually glows at light wavelengths.

Jupiter’s moon Io, the most volcanically active planet in the solar system, was created by tidal heating caused by Jupiter’s immense gravitational pull in Io’s slightly eccentric (elongated) orbit, which lasted 1.77 days. This means that Io is closer to Jupiter at some points and farther away from Jupiter at other points, causing Io to compress and expand respectively.

Over millions of years, constant friction within Io has caused its core to heat up, resulting in the formation of hundreds of volcanoes on Io’s surface but no visible impact craters. As Dr. Kane mentioned, this new exoplanet candidate “experiences 10 million times more tidal energy than Io,” which could raise more questions about its own volcanism or other geological processes . So, what is the significance of the “tidal storm” aspect of TOI-6713.01?

Dr. Kane told Universe Today, “The reason why TOI-6713.01 experiences such a strong tidal force is because the eccentricity of the two outer giant planets forces TOI-6713.01 to also enter an eccentric orbit. Therefore, I call the planet an eccentric orbit. Caught in a perfect tidal storm.

The two outer giant exoplanets of the HD 104067 system forced the innermost TOI-6713.01 into a “perfect tidal storm,” which is somewhat reminiscent of Jupiter’s first three Galilean moons Io, Europa, and Ganymede, which swayed throughout the Gravitational effects on each other in orbit.

However, there are some differences, as Jupiter’s immense gravity is the main force driving Io’s volcanic activity, and all three moons are in what’s called orbital resonance, meaning that their orbits are proportional to each other. For example, Io has two Europa orbits and one Ganymede orbit for every four orbits, making their orbital resonance 4:2:1, which results in each moon having a regular gravitational influence on each other.

Therefore, the tidal storms on TOI-6713.01 are caused by the eccentricity of the two outer giant stars. How does this compare to the relationship between Io, Europa, and Ganymede?

Dr Kane told Universe Today, “The Laplace resonance of the Galilean moons creates a particularly powerful structure, with the regular arrangement of the three moons within regularly forcing Io into eccentric orbits. The HD 104067 system has no resonance, but Still able to produce dynamical configurations since the b and c planets are so massive, so it’s more of a “brute force” effect forcing the inner transiting planets into eccentric orbits.

As mentioned earlier, TOI-6713.01 was discovered using the radial velocity method, also known as Doppler spectroscopy, which means astronomers measured tiny changes in the motion of the parent star as it was affected by the planet in its orbit. slight traction.

These slight changes cause the parent star to wobble as the two celestial bodies pull against each other. Astronomers use spectrographs to detect changes in these wobbles as the star moves “closer” and “further away” from us to search for exoplanets. .

This method has proven to be very effective in finding exoplanets, as it accounts for almost 20% of the total exoplanets confirmed to date, and the first exoplanets orbiting a star like ours were discovered using this method. discovered by a method. However, despite the validity of radial velocity, the study noted how TOI-6713.01 “has not yet been confirmed,” so what additional observations would be needed to confirm its existence?

Dr Cairns told Universe Today, “Because the planet is so small it was difficult to detect it from the radial velocity data. However, the transit looked clean and we have ruled out the possibility of stellar contamination. Extra Transits will help, but we are very confident in the planet’s existence at the moment.

The research comes as the total number of exoplanetary systems approaches 4,200, with more than 5,600 confirmed exoplanets and more than 10,100 candidate exoplanets awaiting confirmation. The architecture of these systems was found to be very different from our solar system, which consists of terrestrial (rocky) planets closer to the sun and gas giant planets farther away from the sun.

For example, hot Jupiters orbit perilously close to their parent stars, some in just a matter of days, while other systems host seven Earth-sized exoplanets, some of which orbit within the habitable zone. So what can this unique solar system structure tell us about exoplanetary systems in general, and what other exoplanetary systems might reflect it?

Dr Kane told Universe Today, “This system is a good example of the extreme environments planets find themselves in. There are several examples of Earth-like planets close to their stars and being heated by the star’s energy, but few with tidal energy from within. Melting Earth situation.

The potential discovery of exoplanets orbiting in “perfect tidal storms” is further evidence of the myriad of characteristics exhibited by exoplanets and exoplanetary systems, while being inconsistent with our own solar system and what astronomers have learned about them to date. A comparison was made. If confirmed, TOI-6713.01 will continue to shape our understanding of the formation and evolution of exoplanets and exoplanetary systems throughout the Milky Way and throughout the universe.

“The universe is such an amazing place!” Dr. Kane told Universe Today. “The interesting thing about this particular project is that everything started from ‘Hmm, this could be fun’ and turned into something more fascinating than I could have ever imagined! Just to show, never miss an opportunity to follow your curiosity .