Hobby–Eberly Telescope

And so that's what this paper does.

And the data they have comes from the Habitable Zone Planet Finder, which is HBF, which is a near-infrared spectrograph on the 10-meter Hobby-Eberly Telescope in Texas, which runs at a resolving power of about 50,000 And what they have is Y-band coverage, and that's what matters because this is where the main phosphorus line is, which is a feature at about 10,600 angstrom-ish.

And so the final sample they have is of 755 FGK stars, dwarfs, and giants.

Some of these come from earlier studies that didn't measure phosphorus, and then have been reanalyzed for this paper from scratch.

Also, because these stars are so dim and Earth-like planets are so small, they can be very difficult to detect and require specialized instrumentation.

So to learn more about GJ 3378b, the authors used the Habitable Zone Planet Finder instrument on the Hobby-Eberly Telescope at the McDonald Observatory in order to study its host star.

As the planet orbits the star, its gravitational force tugs on the star.

This creates a slight wobble, a Doppler shift, which is visible on the host star, and that Doppler shift can be used to calculate a planet's mass and orbit.