Have You Heard of Super-Mercuries?

Image (Credit): Surface of Mercury captured by NASA’s MESSENGER spacecraft.(NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

I often here of super-Earths among the spotted expolanets, but super-Mercuries? They are less common, with only eight spotted to date, including two recently found around exoplanet using the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) spectrograph on the European Southern Observatory’s Very Large Telescope in Chile. The two super-Mercuries were spotted in the star system HD 23472 along with two super-Earths.

Researcher researcher Susana Barros with the Astrofísica e Ciências do Espaço’s, who led the team that found the new super-Mercuries, stated:

For the first time we have discovered a system with two super-mercuries. This allows us to obtain clues about how these planets were formed, which could help us exclude some possibilities. For example, if an  impact large enough to create a Super-Mercury is already very unlikely, two giant impacts in the same system seems very improbable. We still don’t know how these planets are formed but it appears to be connected to the composition of the parent star. This new system can help us find out.

Much of the exoplanet talk to date has been about super-Earths and mini-Neptunes, so it is nice to see a super-Mercury thrown into the mix. With the exoplanet search is still in its early days, expect more local planet terminology to be added to the discussion.

For more on the super-Mercury story, go here.