>>507578766>it has alwaysa star can move up and down on the Hertzsprung Russell diagram in a couple months.
basically a star's location on the HR diagram only depends on its size and the electric current density it is presently experiencing.
If for whatever reason, the strength of that current density should change, then the star will change its position on the HR diagram, perhaps, like FG Sagittae, abruptly.
Otherwise, no movement from one place to another on that plot is to be expected.
And its age remains indeterminate regardless of its mass or spectral type.
This is disquieting in the sense that we are now confronted by the knowledge that our own Sun's future is not as certain as is predicted by mainstream astronomy.
We cannot know whether the Birkeland current presently powering our Sun will increase or decrease, nor how long it will be before it does so.