It cannot sustain the ordinary hydrogen fusion that powers stars.

Here, “sustain” means to keep something going over time.

It cannot sustain the ordinary hydrogen fusion that powers stars.

This is a process in which hydrogen joins together and releases energy. Stars use it to produce power.

The researchers call it an exosatellite, meaning a natural object orbiting a body outside our Solar System.

An exosatellite is a natural object that goes around another object outside our Solar System.

It would give researchers a confirmed example of a satellite outside our Solar System, if the companion is shown to be real and is accepted as a moon or exosatellite.

Here, “exosatellite” means a moon or similar object that orbits a body outside our Solar System.

They used a method called radial velocity.

Radial velocity is a method that uses changes in an object's movement toward or away from us to help find other objects.

The reporting points to follow-up observations, including direct imaging or looking for a transit.

Direct imaging means trying to see an object itself, rather than only measuring its effects.

Direct imaging would mean trying to see the object itself.

Here, it means trying to see the possible moon directly.

The reporting points to follow-up observations, including direct imaging or looking for a transit.

A transit is an event that scientists can look for to help check whether another object is there.

A transit is when an object passes in front of another body from our point of view, and its passage can be detected.

Here, “transit” means one object passing in front of another as seen from Earth.

The reporting points to follow-up observations, including direct imaging or looking for a transit.

These are later observations made to check or learn more about an earlier finding.

Follow-up observations are the next important test.

These are later observations that can help check whether the reported finding is correct.

The reported follow-up discussion says activity in a brown dwarf’s atmosphere or magnetic field can complicate the signal.

Here, “complicate” means make the signal harder to understand or interpret.

A 2023 paper reanalysed observations of two candidates, Kepler-1625 b and Kepler-1708 b, from the Hubble and Kepler space telescopes.

The paper examined the observations again, using a new or different analysis.

So earlier candidates did not become settled discoveries.

Here, these are findings that became accepted as real discoveries, rather than remaining uncertain.

Let me put that plainly: first, scientists have to establish that the companion is really there.

Here, “establish” means show clearly that something is true.

It would give researchers a confirmed example of a satellite outside our Solar System, if the companion is shown to be real and is accepted as a moon or exosatellite.

A satellite is an object that goes around a larger object, such as a moon going around a planet.