In a fourth type, the spectroscopic binary, a star is known to be in
orbit around another star because the lines in its spectrum alternately show motion of approach and recession.
Not exact matches
Because this scenario depends on the presence of nearby
stars, we expect DCBHs to typically form in satellite galaxies that
orbit around larger parent galaxies where Population III
stars have already formed.
The theory goes that before exploding, the progenitor
star has its hydrogen outer coat stolen by a companion
star in
orbit around it, but astronomers have never before been able to spot the thieving companion
because the supernova is so bright.
Because the planets are in such close
orbits around TRAPPIST - 1, some or all of them may be tidally locked, which means that they always present the same side to the
star and the opposite side away from the
star.