No. Do you know what nemesis means? It's a righteous infliction of retribution manifested by an appropriate agent.<br />
And do you know what Tyche is? It's a gentle and non-violent/non-contact martial art practiced by retirement-age Asians to keep their joints mobile and their circulation freely flowing.<br />
The two things are not even related!
Mass extinctions of what?<br />
Asking whether a hypothetical massive planet is actually a hypothetical very small star seems.... preemptive. Why not wait til we actually find anything before we decide what it is?
Planet Tyche might just be a myth no ones sure
I thought Miss Marple was Nemesis. As to Tyche, I know it's been proposed, but have they actually found it?