Things that are very luminous can be seen much further away than things that are very dim. This particular star is a tiny red dwarf, which is so dim we only ju

Things that are very luminous can be seen much further away than things that are very dim. This particular star is a tiny red dwarf, which is so dim we only just found the star itself in 2003. Our best planet-finding methods depend on finding signals in the light output of the host star. This is relatively insensitive to distance, but very sensitive to the properties of the star.