"tight orbit" means being very close to someone or something. It refers to staying very near, like orbiting around them, without much space in between. Full definition
In fact, as another recent modeling study demonstrated, planets in tight orbits around red dwarf stars might be getting lashed by an insane number of high - energy solar flares, stripping their atmospheres faster than they can be replenished. (gizmodo.com)
Earlier this year, astronomers announced the discovery of a massive planet in tight orbit around a star so young it still features a disk of circumstellar gas and dust. (gizmodo.com)
Superflares - According to one recent hypothesis, unusually intense stellar flares from a sun - like («Sol - type») star could be caused by the interaction of the magnetic field of a giant planet in tight orbit with that star's own magnetic field. (members.nova.org)