GJ 1245 A is the brightest member of a close family of three tiny red dwarfs in Cygnus, all of them flare stars that brighten without warning.
At a glance
| type | red dwarf (class M) |
|---|---|
| distance from the Sun | 15 light-years (4.6 pc) |
| its light left it | 15 years ago |
| luminosity | 0.0011 × the Sun |
| radius | 0.14 × the Sun |
| surface temperature | 2,800 K |
Read off the piece’s own catalogue, the same values it draws with.
About GJ 1245 A
GJ 1245 is a triple system: GJ 1245 A has a close, even smaller companion, and a third red dwarf, GJ 1245 B, orbits the pair at a greater distance. All three are very low-mass stars, cool and dim, and none can be seen without a telescope.
The system lies in a part of Cygnus that the Kepler space telescope watched continuously, and its stars were among the nearby red dwarfs whose flares were recorded in great detail there. Small red dwarfs like these have deep, churning outer layers that build strong magnetic fields, and those fields release energy in frequent flares.
What you see in the piece
Fly to it and the members of the system separate into faint red points. From Earth none of them reach the naked-eye limit in the piece.
Questions
What kind of star is GJ 1245 A?
It is a red dwarf (class M) with a surface temperature of about 2,800 K and a luminosity of 0.0011 × the Sun, the brightest member of a small triple system.