Two new worlds of rocky mineral goodness have just been discovered by a star.
The two newly discovered exoplanets are larger than Earth but smaller than an ice giant and are in close proximity to a red dwarf star.
The star is one of the closest multi-world systems to Earth.
This makes it an excellent target for follow-up surveys to try to understand what the exoplanets are made of, and to assess their atmospheres, even if the two worlds are incapable of hosting it themselves.
The two planets in this system are considered to be the best targets for atmospheric study because of their brightness.
There is a question about the atmosphere around these planets. There are signs of water or carbon based species. These planets are great testbeds for exploration.
Astrobiologists are interested in finding planets like Earth, Venus, and Mars because of the number of exoplanets that have been found.
Finding planets similar to Earth in size and composition is one of the top criteria in the search for life outside our solar system.
Most of the exoplanets we've been able to measure tend to fall into the giant category due to their small size and mass. Nearby rocky worlds are also very sought after.
HD 260655 b and HD 260655 c were found because they passed between us and their star. NASA's exoplanet-hunting telescope TESS was used to record the faint dips in starlight caused by exoplanetary transits.
The next step was to check if the star had appeared in previous surveys after Kunimoto spotted the transit dips.
The data from the High Resolution Echelle Spectrometer on the Keck Telescope was made public. The astronomer at the Calar Alto Observatory in Spain had recorded the star as well.
This makes a huge difference to exoplanet science, because it shows whether or not a star is moving.
Kunimoto says that every planet around a star will have a pull on it. A planetary-mass object tugging on a star is what we are looking for.
The team was able to confirm the existence of two exoplanets with the help of both sets of data.
The size of the exoplanet is determined by how much light is blocked from the star. The data can be used to calculate the exoplanet's location.
HD 260655 b is an exoplanet that is 1.2 times the size of Earth and twice the mass of Earth. HD 260655 c is three times the mass of Earth and 1.5 times the size.
The densities show that the two planets are likely to be rocky.
Even though the star is cooler and dimmer than the Sun, the planets are too hot to live on. HD 260655 b has an average temperature of 814 degrees Celsius and HD 260655 c has an average temperature of 534 degrees Celsius.
The range is too hot for liquid water to exist on the surface.
Both exoplanets could still have atmospheres, which should be of interest to the newly deployed James Webb Space Telescope, which includes peering at exoplanet atmospheres.
There could be more than one exoplanet that we haven't discovered yet.
There are many multi-planet systems around small stars like this one.
Hopefully we will find more and one will be in the right place. That's a good way to think.
The team presented their findings at the meeting.
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