Are stars near the ecliptic the only stars from which Earth would appear to transit the Sun? The majority of exoplanets we have discovered have been found by the transit method, in which a planet passes in front of its parent star and by analyzing the light curve we can deduct its characteristics.
Say there was intelligent life around a nearby star, could they only see the Earth transit in front of the Sun if they were located around the ecliptic?
Yes. Heller and Pudritz 2016 define an Earth transit zone (ETZ) within 0.26° of the ecliptic and a restricted ETZ (rETZ) half as wide.
They also list 82 Sun-like stars in the rETZ and within 1 kiloparsec of the Sun.
Sheikh et al. 2020 report on a search for artificial radio signals from 20 of those.