No, this isn’t a story about lonely astronomers working at remote mountain observatories scanning the stars for a glimpse of a hot alien life form like Seven of Nine or Sally Solomon or Starman … but it’s close.
A team of astronomers from the Center for Exoplanets and Habitable Worlds at Penn State University have started a project called “Glimpsing Heat from Alien Technologies” (G-HAT) which involves looking for galaxies generating excessive amounts of radiation in the mid-infrared (MIR) wavelengths. This radiation may be the result of a large alien civilization generating heat waste as a result of technology or just everyday living.
The G-HAT team is using the images generated by the Wide-field Infrared Survey Explorer (WISE) which released an infrared map of the entire sky in 2012. Any galaxy emitting greater than 10 percent of its light in the mid-infrared range is a potential candidate for further study. In its initial pass, team leader Jason Wright says they found about 50 galaxies giving out “a superlative amount of mid-infrared light.”
Before you get too excited about finding signs of hot alien life, Wright has a few words of caution.
If by 'found them' you mean that WISE detected the waste heat from them, then yes, that's right – if these sorts of energy-hungry civilizations exist, WISE should have detected them. Distinguishing that waste heat from ordinary astrophysical dust will be very difficult in many cases, and proving it's of alien origin will be even harder.
The initial observations are reported in the Astrophysical Journal. The search through WISE images will continue to isolate the cause of the radiation in these overheated galaxies.
Knowing astronomers, they probably have a couple of hot ones they're keeping to themselves.