| > What's the typical time scale for a transit? Generally measured in hours, or minutes. For example, if we were observing our system with perfect alignment, Earth's transit would be about 12 hours, Jupiter's transit around 29 hours. > Also, why use transits instead of the Doppler method? Quantity. PLATO can observe a sizeable portion of the sky at once, 100k+ of stars. With Doppler method the quantities are smaller + afaik there is a trade-off between number of stars being observed and the velocity we can measure. So to find Earth-like planets around Sun-like stars, we would likely have to go one or a few stars at a time. > Has this patch of sky been selected based on previous Doppler method star studies? I am not actively involved anymore. So I am not sure if they have already picked what part of the sky they PLATO is going to be observing. The previous Doppler method (aka as radial-velocity or rv method) star studies play a role, not only because if there's one planet, there might be more, but also because rv gave information about the star. However, keep in mind that this is to find new exoplanets, less to find out more data about existing ones. Rv will definitely be used along side PLATO, to confirm and gather more information about exoplanets that PLATO finds. |
…per year, for Earth; per ~12 years for Jupiter is I think what the GP was asking.
This is extremely dependent on the radii of the inner and outer limits of the the habitable zone for any given star, though, as well as the star’s mass.