Re: A super-Earth has been discovered just 10 light-years away

"a425couple"  wrote in message news:[email protected]...

from
https://www.ecoticias.com/en/a-super-earth-has-been-discovered-just-10-light-years-away-which-could-harbor-an-atmosphere-and-water-but-reaching-it-with-current-technology-would-take-us-about-15000-years/31607/#google_vignette
...
They used the radial velocity method, which detects a planet by
measuring a star’s tiny back-and-forth motion.

The signal was measured with the HARPS spectrograph and the ESPRESSO
spectrograph, instruments operated in Chile by the European Southern
Observatory.

------------------------------
In college I learned how scientific instruments work, and have tried to keep 
up with advances.

These spectroscopic instruments which measure radial velocity (toward/away) 
from Doppler shift can detect a change of 3 feet per second, 2 miles per 
hour. A star and planet orbit around their combined center of gravity, the 
star is slightly offset away from the orbiting planet, which gives the 
measurable wobble in the star's radial velocity and spectral lines.

https://en.wikipedia.org/wiki/Fraunhofer_lines
https://phys.libretexts.org/Bookshelves/University_Physics/University_Physics_(OpenStax)/University_Physics_III_-_Optics_and_Modern_Physics_(OpenStax)/05%3A__Relativity/5.08%3A_Doppler_Effect_for_Light

For the Earth and Sun the radial velocity variation observed from another 
star would be around 4 inches per second, extremely difficult to measure 
even in the lab.

https://www.jpl.nasa.gov/news/tiny-measurement-gives-big-boost-to-planet-hunt/
But...
https://en.wikipedia.org/wiki/Space_Interferometry_Mission