PHL @ UPR Arecibo - Arecibo Wow!

The Arecibo Wow! (AWOW) is a technosignature research project using archived data from the Arecibo Observatory's 305-meter and 12-meter telescopes. The primary objective of this project is to identify and explain signals similar to the Wow! Signal detected in 1977 by the Ohio State University's Big Ear radio telescope.

First Results: An Astrophysical Explanation for the Wow! Signal

The Ohio State University Big Ear radio telescope detected in 1977 the Wow! Signal, one of the most famous and intriguing signals of extraterrestrial origin. Characterized by its strong relative intensity and narrow bandwidth near the 1420 MHz hydrogen line, its source has never been detected again despite numerous follow-up attempts.

Arecibo Wow! is a new technosignature project using archived data from the Arecibo Observatory. Here we present our first results of drift scans made between February and May 2020 at 1420 MHz. The methods, frequency, and bandwidth of these observations are similar to those used to detect the Wow! Signal.

We report the detection of narrowband signals (≤10 kHz) near the hydrogen line similar to the Wow! Signal, although two-orders of magnitude less intense and in multiple locations. Despite the similarities, these signals are easily identifiable as small interstellar clouds of cold hydrogen (HI) in the galaxy.

We hypothesize that the Wow! Signal was caused by a sudden brightening of the hydrogen line in these clouds triggered by a strong transient radiation source, such as a magnetar flare or a soft gamma repeater (SGR). A maser flare or superradiance mechanisms can produce stimulated emission consistent with the Wow! Signal.

Our hypothesis explains all observed properties of the Wow! Signal, proposes a new source of false positives in technosignature searches, and suggests that the Wow! Signal could be the first recorded event of an astronomical maser-like flare in the hydrogen line.

Our proposed Wow! Signal emission source is a region of a cold HI cloud that emits a maser-like flare or superradiance beam. A strong radiation source, such as a magnetar flare, triggers this event. The trigger beam is not necessarily observed depending on its distance, size, and separation angle.

Resources

1st Paper: Arecibo Wow! I: An Astrophysical Explanation for the Wow! Signal
2nd Paper: Arecibo Wow! II (in preparation)
General Summary
Wow! Signal Classic
Wow Data (new)

Research Team

Abel Méndez, PHL @ UPR Arecibo
Kevin Ortiz Ceballos, Center for Astrophysics | Harvard & Smithsonian
Jorge I. Zuluaga, SEAP/FACom Institute of Physics, University of Antioquia
Kelby D'Angelo Palencia-Torres, PHL @ UPR Arecibo & UPR Rio Piedras
Alisson Smith, UPR Mayagüez
Emmanuel J. Morales Butler, UPR Utuado
Héctor Socas-Navarro, Instituto de Astrofísica de Canarias (IAC)
David Kipping, Columbia University

Stellar Maps in Equatorial and Galactic Coordinates

These star maps show the locations, in equatorial and galactic coordinates, of the stars with potentially habitable worlds. They also include the location of the Wow! Signal, the Arecibo Message, and the five stellar probes, Pioneers 10 and 11, Voragers 1 and 2, and New Horizons. These maps were created with tools and data from the PHL Habitable Worlds Catalog, NASA Exoplanet Archives, and D3-Celestial. Credit: PHL @ UPR Arecibo.