3 ms·
Parallax is not the only way. Cepheid variables are also used, I think more so than parallax, since parallax is only accurate for somewhat nearby stars. https:
by crazydoggers 8y ago
Parallax is not the only way. Cepheid variables are also used, I think more so than parallax, since parallax is only accurate for somewhat nearby stars.
https://en.m.wikipedia.org/wiki/Cepheid_variable https://en.m.wikipedia.org/wiki/Cepheid_variable
- antognini 8y agoYes, but Cepheids are calibrated, fundamentally, by parallax. (I believe that no Cepheids were actually close enough to be calibrated directly by parallax, at least until Gaia, so they had to be calibrated by other techniques which were, in turn, calibrated by parallax.)