Around one of the galaxy's oldest stars, an orange dwarf named TOI-561 just 280 light-years away, astronomers have found three orbiting exoplanets - one of which is a rocky world 1.5 times the size of Earth, whipping around the star on a breakneck 10.5-hour orbit.

Obviously an exoplanet so close to its star isn't likely to be habitable, even if it is rocky like Earth, Venus and Mars.

But the TOI-561 system, planets and all, is one of the oldest ever seen, at an estimated age of around 10 billion years.

TOI-561 d, the outermost, is around 2.3 times the size of Earth, with an orbital period of 16.3 days.

TOI-561 c is 2.9 times the size of Earth, with an orbital period of 10.8 days.

And TOI-561 b is 1.45 times the size of Earth, with an orbital period of just over 10.5 hours.

Finding planets like TOI-561 b can help constrain those models, which in turn could help us locate more ancient rocky exoplanets.