Bibcode
Gilbert, Emily; Burt, Jennifer; Barragán, Oscar; Siegel, Jared; Suárez Mascareño, Alejandro; Silva, André; Luque, Rafael; Rogers, James; Lee, Eve; Lopez, Eric; Vanderburg, Andrew; Clement, Matthew; Youngblood, Allison; Mamajek, Eric; Sousa, Sérgio; The TOI-700 Collaboration
Bibliographical reference
American Astronomical Society Meeting Abstracts
Advertised on:
6
2025
Citations
0
Refereed citations
0
Description
The TOI-700 system was discovered in 2020 using data from NASA's TESS mission. At that time, there were three known planets, including TOI-700 d, the first Habitable Zone planet from TESS. In 2023, a fourth planet was discovered in the system, TOI-700 e, orbiting in the stars Optimistic Habitable Zone. Now, five years after its initial discovery with TESS, we provide an update on this benchmark system. Here, we report new exoplanet mass measurements from radial velocity observations with the VLT/ESPRESSO spectrograph of TOI-700. We find that TOI-700 c (2.65 R⊕) is a low-mass (2.5 M⊕) planet, which must have a hydrogen/helium dominated atmosphere given its low bulk density (0.73 g cm−3). Furthermore, the small (1.16 R⊕), HZ planet, TOI-700 d, has a mass of 2.4 M⊕, implying a rocky composition. Given that TOI-700 c and d have similar masses, the presence of TOI-700 c, a puffy sub-Neptune, orbiting interior to the rocky TOI-700 d implies that d might be able to maintain a heavier, secondary atmosphere as they were subject to the same stellar history.