In 2023, scientists discovered several stunning exoplanets. Last year, planetary scientists added a number of exciting new worlds to the exoplanet catalog of more than 5,000 objects. Among them are planets that we have never seen before.
The James Webb Space Telescope has discovered that the exoplanet Smertrios has its own atmosphere. Earlier this year, observations made using a space telescope confirmed the presence of heavy elements – carbon and oxygen – in the atmosphere of the distant exoplanet HD149026b. The planet is better known as Smertrios. This discovery came as a surprise to astronomers, since the gas giants of our solar system, such as Jupiter and Saturn, contain predominantly only hydrogen and helium in their atmospheres. The general rule is: the larger the planet, the less heavy elements there are in its atmosphere. This discovery changed the understanding of the dependence of elements on the mass of the planet.
NASA’s TESS Transiting Exoplanet Survey satellite added about 2,000 worlds to its list of exoplanets, but this planet, a gas giant called TOI-4600c, has particularly piqued the interest of planetary scientists. Most discovered exoplanets orbit very close to their host star, but TOI-4600c orbits its star every 482.82 days or 16 months. This makes it the longest year of any planet discovered by TESS. The gas giant has a temperature of -110 degrees Fahrenheit or -78 degrees Celsius at the surface.
Located just 100 light-years from our solar system, scientists have discovered a planetary system in which six planets orbit very close to their parent star – so close that all six planets could fit within the distance between Mercury and our Sun. Astronomers also believe that the planetary system has remained unchanged for over a billion years because the planets’ orbits are close to a perfect mathematical resonance.
The study found that a massive exoplanet called LHS 3154 b, which is 13 times more massive than Earth, orbits an ultra-cool dwarf star. The planet is similar in size to Neptune, but the star is nine times less massive than the Sun. The ratio between the Neptune-sized world and its parent star, which is 51 light years away, is 100 times the ratio of the masses of Earth and the Sun.
Using 17 years of data, astronomers have created a time-lapse video of the orbit of exoplanet Beta Pictoris b. The data was compressed into a 10-second video that captured 75% of the planet’s orbit around its parent star, which takes 23 Earth years to complete. The planet is located in a system 64 light years from Earth, and the planet itself has a mass 12 times that of Jupiter, the largest planet in our solar system.
Observations with the JWST Mid-Infrared Instrument (MIRI) have revealed that the two inner planets of the TRAPPIST planetary system are likely to have no atmosphere. TRAPPIST-1b, which is slightly more massive than Earth, is likely bare rock with no atmosphere, with a scorching surface temperature of 232 degrees Celsius (450 degrees Fahrenheit). The results were complemented by similar results for TRAPPIST-1c, the next planet in the system, three months later. Astronomers attribute the lack of atmosphere on these planets to the vigorous activity of their home star.
Planetary scientists aimed JWST at a mini-Neptune planet called Gliese 1214 b and found that it was surrounded by a dense haze, or layer of clouds. Gliese 1214 b was initially difficult to observe due to its reflective atmosphere, but researchers believe the planet may contain large amounts of water vapor. However, the planet, located 48 light years away, orbits very close to its host star, so it is unlikely that there will be liquid oceans on its surface. Mini-Neptunes, planets smaller than Neptune but larger than Earth, are, oddly enough, absent from our Solar System.
Astronomers have identified an exoplanet called LTT9779 b, which reflects 80% of the light falling on it from its parent star. By comparison, the Earth reflects 30% of its light. The ultra-hot planet, located 264 light-years from Earth, is exceptionally reflective due to the high proportion of metals in its atmosphere. Because the planet is five times wider than Earth, it deserves the title of “largest cosmic mirror ever discovered.”
Astronomers have observed an exoplanet located about 950 light-years from Earth explosively losing its atmosphere due to its extreme proximity to its host star. The planet, known as HAT-P-32 b, has a mass of about 68% of the mass of Jupiter, but is twice as wide as the largest planet in the solar system. HAT-P-32 is just 3.2 million miles from its parent star, or about 3% of the distance between Earth and the Sun, and orbits every 2.2 days. This proximity means the gas giant is being fried by radiation from its parent star, classifying HAT-P-32 b as a “hot Jupiter” planet. Astronomers used telescopes from Earth to observe HAT-P-32 b’s gaseous tail, created from helium leaking from its atmosphere.
Although binary star systems, in which two stars orbit each other, are common in space, it is much less likely that these systems contain planets. This is because binary stars are likely to activate planet-forming disks during the early stages of planetary systems. Only one such binary system was known to contain multiple planets, but earlier in those years, scientists discovered another multi-planet system orbiting a pair of stars. Astronomers examined the binary system TOI-1338, located approximately 1,320 light-years from Earth, and discovered a near-Earth planet, dubbed TOI-1338b, orbiting a pair of TOI-1338 stars. In their failed attempts to measure the planet’s mass, they discovered another planet.
On a planet where temperatures reach 4,350 degrees Fahrenheit (2,400 degrees Celsius), hot enough to vaporize iron, researchers have identified 11 chemical elements found in the atmosphere, indicating that the atmosphere is composed of rock-forming elements. Located about 634 light-years away, this planet gets its temperature from its close proximity to its star. Classified as a “super-hot Jupiter”, the exoplanet is a massive planet that is incredibly close to its star. The exoplanet is a twelfth the distance from its star WASP-76 than Mercury is from the Sun.
Using data from NASA’s Transiting Exoplanet Survey Satellite (TESS), scientists have identified eight new exoplanets that are considered “super-Earths,” a class of exoplanets that are larger than Earth but smaller than Neptune. Astronomers are particularly interested in this class of planets because they represent a gap in the exoplanet data, namely the lack of knowledge about planets of this particular mass. Researchers hope that by discovering more super-Earths, they will be able to understand why there is such a gap in exoplanet data.