TOI-1685 b: On this exoplanet, a “year” lasts 0.67 state parliaments

On TOI-1685 b, a newly discovered exoplanet, a year only takes 0.67 Earth days. It may sound strange, but observations by a team of astronomers led by Paz Bluhm from the University of Heidelberg in Germany have shown this.

TOI-1685 b orbits a red dwarf (or M dwarf) named TOI-1685, which is located approximately 122 light years from Earth. As notes, stars of this type are much smaller and darker than our sun. However, the exoplanet’s proximity to its host star means that its surface temperature is extremely high. The researchers estimate this to be around 790 ° C.

Discovered by the TESS telescope

TOI-1685 b was first discovered thanks to observations from the US space agency’s Transiting Exoplanet Survey Satellite (TESS). As the name suggests, TESS’s job is to search the sky for transits, tiny dark spots that appear when planets pass in front of their host stars.

The telescope discovered such a signature around the red dwarf TOI-1685. Convinced that they had discovered an exoplanet, Bluhm and his colleagues turned to the CARMENES spectrograph.

Recognize gravitational disturbances

As a reminder: The CARMENES spectrograph is a German-Spanish instrument that is mounted on the 3.5-meter telescope of the Calar Alto observatory in the Spanish province of Almería. It was built to find Earth-like planets orbiting dwarf M-stars.

Illustrative picture. Photo credit: Shutterstock / AleksandrMorrisovich

To do this, he uses the radial velocity method (Doppler) to reveal the vibrations in the motion of a star caused by the gravitational interaction with the planets in the area. Thanks to this instrument, the team was able to confirm the nature of TOI-1685 b, which is an exoplanet. The data provided by CARMENES also made it possible to learn more about the celestial body.

A sparse planet

Therefore, in addition to its orbital period of just 0.67 days, exoplanet TOI-1685 b is known as super-earth, which is roughly 1.7 larger than our planet and 3.8 times as massive. Its apparent density of 4.2 grams per cubic centimeter makes it the least dense ultra-short-lived planet around a previously known M dwarf.

For comparison, the bulk density of the earth is 5.5 grams per cubic centimeter. In addition, Bluhm and colleagues claim to have discovered another point caused by an object orbiting the red dwarf TOI-1685. It could be another planet. Future observations should confirm this hypothesis.