An approximation to find out the supply of the WOW! Sign

An approximation to determine the source of the WOW! Signal

Alberto Caballero

This article analyzes which of the thousands of stars in the WOW! The signal region could have the highest chance of being the actual signal source, provided it comes from a star system similar to ours. A total of 66 type G and K stars are sampled, but only one of them is identified as a potential Sun-like star based on the information available in the Gaia Archives.

This candidate source, named 2MASS 19281982-2640123, therefore becomes an ideal target for observations in search of potentially habitable exoplanets. Another 14 potential Sun-like stars (with estimated temperatures between 5,730 and 5,830 K) are also in the region, but information about their luminosity and radius is not known.
Keywords: WOW! Signal, SETI, search for extraterrestrial intelligence, interstellar radio message.


From October 2020 this is WOW! The signal remains the strongest candidate SETI signal. It has been suggested that the signal was generated by hydrogen clouds from comets 266 / P Christensen and P / 2008 Y2 (Paris and Davies, 2015). However, this hypothesis has been rejected by the scientific community and the source of the signal remains unknown.

Despite the WOW! Signal never repeated, the key was its duration. The signal lasted 72 seconds, but since this was the maximum time the Big Ear radio telescope could observe, it is likely that the signal would have lasted longer.

The main problem, however, is that the signal never repeats itself. Follow-up observations of the area made by many observatories for several years did not reveal any further signal (Gray and Ellingsen, 2002). However, the fact that the signal never repeated itself does not necessarily mean that it was generated by extraterrestrial intelligence.

If we analyze the history of the (few) radio signals that humanity sent to multiple destinations in hopes of contacting a civilization, none of these transmissions had a long duration or were sent repeatedly for a long time. An alien civilization could have opted for similar behavior.

Few attempts have been made to pinpoint the exact location of the WOW! Signal due to difficulty. Although it was only detected in one of the two feed horns of the radio telescope, the data was processed in such a way that we cannot determine which of the feed horns actually received the signal.

The other reason that makes it difficult to pinpoint the exact source is the high uncertainty in the declination: 20 arc minutes. The image below shows an approximation of the two sections of the sky that might contain the signal source, each with thousands of stars.

Figure 1: The two regions in which the WOW! The signal could have originated
Source: Pan-STARRS / DR1

The coordinates of the signal are RA: 19h25m31s ± 10s (for the positive horn), 19h28m22s ± 10s (for the negative horn) and DEC: -26 ° 57 '± 20', both in J2000 equinox (Ehman, 1997). This article attempts to make a list of possible sources of signals, provided that the exoplanet is similar to Earth if it was created by an alien civilization.