Astronomers have discovered a distant alien world that is 30% more massive than the largest planet in our solar system, Jupiter.
The universe is a massive place. It is so big that the human mind has a hard time grasping it. In fact, the human mind cannot even gasp the true size of our own galaxy, the Milky Way. Believed to be home to between 100 and 300 billion stars, and there are likely to be a similar amount of planets if each sun has at least one world orbiting it.
As of writing, astronomers have discovered — confirmed — 5,178 exoplanets, and there are 8,933 planets still awaiting confirmation. In addition, these planets and potential planets are found in 3,870 star systems astronomers have identified within the Milky Way galaxy. This number increases with new observations of the night sky. A team of international astronomers has discovered a new, old, and warm planet orbiting a G-dwarf star using the Transiting Exoplanet Survey Satellite (TESS). This new exoplanet, named TOI-5542 b, is about 30% more massive than Jupiter, our solar system’s largest gas giant.
In order to find transiting exoplanets, the Transiting Exoplanet Survey Satellite surveys about 200,000 bright stars near the sun. In all, nearly 6,000 candidates (TESS Objects of Interest, or TOI) have been discovered so far. Of those, 256 have been confirmed as actual exoplanets. An international team of astronomers led by Nolan Grieves of the University of Geneva in Switzerland has recently verified another TOI monitored by TESS. TOI-5542 (other designation TYC 9086-01210-1) is a metal-poor G dwarf with a transit signal found in its light curve. By observing this signal with the CORALIE and HARPS spectrographs, scientists were able to confirm its planetary nature. TOI 5542 is located at a distance of 1,154 light-years away from the Sun.
According to the researchers, they discovered and characterized the warm Jupiter TOI-5542 b as two separate transit events 375.6 days apart. Its radius is approximately 1.01 Jupiter radii, and its mass is approximately 1.32 Jupiter masses, which gives its density at 1.6 g/cm3. Each 75.12 days, it orbits its parent star at a distance of 0.33 AU. According to astronomers, the planet has an equilibrium temperature of 441 K, making it a warm Jupiter. A warm Jupiter is a giant planet with an orbital period of 10 to 200 days. A dip in occupation between hot Jupiters and cold Jupiters corresponds to the so-called “period valley.”
Having a radius of about 1.06 solar radii, TOI-5542 is 11% less massive than the sun and is a spectral type G3V. Its estimated age is 10.8 billion years, and its effective temperature is approximately 5,700 K, with a luminosity somewhere around 1.05 solar luminosities. With TOI-5542 being nearly 11 billion years old, researchers emphasize that it is one of the oldest known long-period Jupiter’s with an estimated age. This is one of the oldest known warm Jupiters, and it is cool enough not to be affected by inflation due to stellar incident flux, making it an important part of planetary composition and formation studies,” said the paper’s authors.
The researchers noted that due to the circular orbit of TOI-5542 b, it is difficult to predict the formation or migration of this planet. Scientists are nonetheless confident that it probably formed via disk migration or in situ formation, as those mechanisms are more likely to result in planets orbiting their stars eccentrically. The discovery was reported in a paper published on the arXiv pre-print server.