A Pair of Rocky Exoplanets Twice Larger Than the Earth Discovered

Using the Transiting Exoplanet Survey Satellite or TESS of NASA, astronomers have discovered a pair of rocky exoplanets orbiting a red dwarf star identified as the HD 260655.

A Paris Beacon-News report said that the newly discovered extraterrestrial worlds are bigger and at least twice larger than the Earth.

TESS is performing a survey of approximately 200,000 of the brightest stars close to the sun with the objective of searching for traveling exoplanets.

So far, the survey satellite has identified more than 5,600 candidate exoplanets, TESS Objects of Interest or TOI, of which 205 have been verified thus far.

Exoplanets Monitored by NASA's TESS

Now, a group of astronomers led by the University of Chicago's Rafael Luque confirmed another pair of planets monitored by TESS.

According to the team, the transit signals have been identified in the light curve of the bright M dwarf HD 260655 or TOI-4599.

Essentially, these signals' planetary nature was verified by archival and new accurate radical velocity or RV measurements.

This work demonstrates the detection and characterization of a multi-planetary system that orbits the M dwarf HD 260655 nearby.

More Than 2X Larger than Earth

Transit observations from TESS found two tiny planet candidates that were verified with independent RV data from the CARMENES and HIRES instruments taken since 1998 and 2016, respectively, the researchers wrote in the paper published in ArXiv.org.

The exoplanet nearer the parent star was given the designation, HD 260655 b. It has a radius of approximately 1.24 Earth radii and is roughly 2.14 times larger than this planet, which yields a density level of 6.2 g/cm3.

HD 260655 b is orbiting its host every 2.77 days at a distance of roughly 0.03 AU from it. Its equilibrium temperature was approximated to be 709 K.

The second newly discovered planet identified as HD 260655 c is more massive compared to its neighbor. The results have shown that it has a radius of 1.53 Earth radii, while the mass is estimated at 3.09 Earth masses.

Consequently, the density of this planet was computed to be 4.7 g/cm3. Meanwhile, HD 260655 c is separated from the parent star by 0.047 AU. It has an orbital duration of 5.7 days, and an equilibrium temperature of roughly 557 K.

Excellent Targets for Further Atmospheric Investigations

The star HD 260655, found roughly 32.6 light-years away, is of "spectral type M0 V" and is approximately 56-percent tinier and less massive compared to the sun.

Furthermore, the star comprises a metallicity level of -0.43 and is approximated to be from two to eight billion years old.

HD 260655 is somewhat bright, with a seeming brightness of 6.7 mag, and its effective temperature is 3,803 K.

Summing up the findings, according to a report from the Space Flight Journal said, the study authors noted that their discovery has made HD 260655 the fourth closest known multi-transiting planetary system.

They also said that because of the host star's somewhat high apparent brightness, the two newfound planets would be excellent targets to further atmospheric investigations.

Related information about the discovery of two exoplanets is shown on Amaze Lab's YouTube video below:

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