Read about the coolest discoveries, research updates, and images of this week’s astronomy: A JWST discovery of carbon dioxide in the atmosphere of an exoplanet, an extrasolar world covered in water, and a new planetary nebula.
JWST discovery of carbon dioxide in the atmosphere of an exoplanet
For the first time, astronomers have found solid evidence of carbon dioxide in the atmosphere of an exoplanet! Carbon dioxide is an important component of the atmospheres of planets in our solar system, found on rocky planets like Mars and Venus as well as gas giants like Jupiter and Saturn. For exoplanet researchers, it is important both as a gas they are likely to be able to detect on small rocky planets and as an indicator of the overall abundance of heavy elements in the atmospheres of giant planets.
Stars and gas giant planets are made primarily of the lightest elements, hydrogen and helium, but the abundance of heavier elements is a critical factor in planet formation. Right now, carbon dioxide is the best measuring stick that we have for metals in exoplanets, so it’s really great that we can see it so clearly!
If you want to read the full discover paper, go here: https://arxiv.org/abs/2208.11692
An extrasolar world covered in water
An international team of researchers has announced the discovery of a probable ocean planet only 100 light-years from earth! The exoplanet is slightly greater in size and mass than Earth and is located at a distance from its star where its temperature would be neither too hot nor too cold for liquid water to exist on its surface. The astronomers believe it could be an “ocean planet,” a planet completely covered by a thick layer of water, similar to some of Jupiter’s and Saturn’s moons.
To determine the planet’s mass, the researchers then observed the system with SPIRou, an instrument installed on the Canada-France-Hawaii Telescope in Hawaii. Designed in large part in Canada, SPIRou is ideal for studying low-mass stars such as TOI-1452 because it operates in the infrared spectrum, where these stars are brightest. Even then, it took more than 50 hours of observation to estimate the planet’s mass, which is believed to be nearly five times that of Earth.
The exoplanet TOI-1452 b is probably rocky like Earth, but its radius, mass, and density suggest a world very different from our own. Earth is essentially a very dry planet; even though we sometimes call it the Blue Planet because about 70% of its surface is covered by ocean, water actually only makes up a negligible fraction of its mass—less than 1%.
Water may be much more abundant on some exoplanets. In recent years, astronomers have identified and determined the radius and mass of many exoplanets with a size between that of Earth and Neptune (about 3.8 times larger than Earth). Some of these planets have a density that can only be explained if a large fraction of their mass is made up of lighter materials than those that make up the internal structure of the Earth such as water. These hypothetical worlds have been dubbed “ocean planets.”
To read the whole article, click here: https://iopscience.iop.org/article/10.3847/1538-3881/ac7cea
A new planetary nebula
In much less sensational but nonetheless still interesting news, Astronomers found a planetary nebula in the star cluster M37!
Planetary nebulae (PNe) are expanding shells of gas and dust that have been ejected from a star during the process of its evolution from a main sequence star into a red giant or white dwarf. They are relatively rare, but are important for astronomers studying the chemical evolution of stars and galaxies.
I think it’s quite cool how we still are discovering new large objects hundreds of years after we first started to look up at the night sky – who knows what the next years of JWST and RST will bring!