Starship Asterisk*

Host star TOI-5205 is only about four times the size of Jupiter, yet it is orbited by a Jupiter-sized planet.

Artist's conception of a large gas giant planet orbiting a small red dwarf star called TOI-5205. Image by Katherine Cain, courtesy of the Carnegie Institution for Science.

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A team of astronomers led by Carnegie’s Shubham Kanodia has discovered an unusual planetary system in which a large gas giant planet orbits a small red dwarf star called TOI-5205. ...

Smaller and cooler than our Sun, M dwarfs are the most common stars in our Milky Way galaxy. Due to their small size, these stars tend to be about half as hot as the Sun and much redder. They have very low luminosities, but extremely long lifespans. Althoughred dwarfs host more planets, on average, than other, more massive types of stars, their formation histories make them unlikely candidates to host gas giants.

The newly discovered planet—TOI 5205b—was first identified as a potential candidate by NASA’s Transiting Exoplanet Survey Satellite (TESS). Kanodia’s team, which included Carnegie’s Anjali Piette, Alan Boss, Johanna Teske, and John Chambers, then confirmed its planetary nature and characterized it using a variety of ground-based instruments and facilities.

• Astronomical Journal 165(3):120 (2023 Mar 01) DOI: 10.3847/1538-3881/acabce
• arXiv > astro-ph > arXiv:2209.11160 > 22 Sep 2022 (v1), 21 Feb 2023 (v3)