0
0
It is located near a small star and is only about 18 light-years away from Earth. This distance is relatively small on a cosmic scale.
A planet near a zone with suitable conditions
The red dwarf star named GJ 251 is located in the constellation Gemini. Its light signals were studied over a long period of time from various observatories. This is how the planet GJ 251 c became visible. It has about four times the mass of our Earth and is likely to consist of solid material. The planet moves in a region around its star where temperatures could theoretically allow liquid water to exist on its surface—but only if the planet has a suitable envelope of gases.
Unclear state of the gaseous envelope
It is not yet known whether the planet actually has a gaseous envelope. This will only be verifiable with future large telescopes. Devices from the so-called 30-meter class could analyze the light reflected from the surface or the gaseous envelope. A planned space telescope, currently scheduled for the 2040s, will likely be necessary for a complete investigation.
How the planet was found
To measure subtle fluctuations in the star’s light, the team evaluated data sets collected over a period of about 20 years. Such fluctuations are caused by the gravitational pull of an orbiting planet and manifest themselves in tiny changes in the wavelength of the starlight.
Initially, the group focused on an already known planet in the same system. But upon closer inspection, another signal was noticed that differed from that of the known planet. This was confirmed with the help of an exact instrument at the McDonald Observatory in Texas (USA). Another measuring instrument at the Kitt Peak National Observatory in Arizona (USA) subsequently confirmed the orbital period of around 54 days around the star.
Why this planet is interesting
GJ 251 c orbits slightly further away from its star than many other planets around similar stars. This means it could be less affected by particle streams from the star. If it has a sufficiently dense envelope of gases and a stable magnetic field, this could create good conditions for stable surface conditions. However, research will only be able to clarify whether this is actually the case in the coming decades. The study was published on October 23, 2025, in the Astronomical Journal.
This post has already been read 33 times!
