HR 7672 B is a companion brown dwarf, a.k.a. a failed star whose interior is not hot enough to burn hydrogen into helium, the definition of a star. It is unique in its own right because brown dwarfs are rare, and brown dwarfs for which we have mass measurements are even rarer. Knowing the mass of HR 7672 B makes it a benchmark brown dwarf, a benchmark against which we can test the formation of low-mass companions around solar-type stars.

In 2022, we set a benchmark to perform spectral analysis. We first tested our code on existing synthetic spectra for which we knew the ground truth. Then we applied the code to the data for HR 7672 B. The result was that HR 7672 B shares a chemical composition similar to that of the primary star HR 7672 A, an expected result that we robustly showed.

Around HR 7672 B, we searched for exomoons using the radial velocity technique. The sensitivity at ~1% mass ratio was not sufficiently high yet. However, we will be able to find Galilean moons around other exoplanets and brown dwarfs with future instruments at extremely large telescopes.