Possibility of a Coordinated Signaling Scheme in the Galaxy and SETI Experiments

Abstract

We discuss a Galaxy-wide coordinated signaling scheme with which a SETI observer needs to examine a tiny fraction of the sky. The target sky direction is determined as a function of time, based on high-precision measurements of a progenitor of a conspicuous astronomical event such as a coalescence of a double neutron star binary. In various respects, such a coordinated scheme would be advantageous for both transmitters and receivers, and might be widely prevailing as a tacit adjustment. For this scheme, the planned space gravitationalwave detector LISA and its follow-on missions have a potential to narrow down the target sky area by a factor of 10 3-4 , and could have a large impact on future SETI experiments.

Search for Galactic Civilizations Using Historical Supernovae

“…2.1. original proposal in Seto (2019) As a simple component model, let us consider transmissions of short duration signals along an arbitrary straight line in the Galaxy (see Fig. 1).…”

“…For an interstellar signaling, borrowing the phrases from Schelling (1960), uniqueness, symmetry and geometrical configuration would be relevant for converging a tacit adjustment. In this context, Seto (2019) pointed out that the concurrent signaling scheme could be worth considering as a prevailing signaling protocol. In that scheme, a sender transmit intentional signals by using a conspicuous astronomical burst.…”

“…However, for the concurrent signaling scheme, an intentional signal is synchronized with the reference burst at infinite distance (Seto 2019). At finite distances from the burst, both the senders and searchers need to complete their operations (transmissions and receptions) basically before observing the burst itself.…”

Interstellar Communication Network. I. Overview and Assumptions

“…A set of schemes have been proposed for the scenario where the participants are usually located on planets, and are not aware of each other's existence. To determine the location and time for initiating a communication, numerous coordination schemes have been proposed, synchronized through the gravitational waves of binary neutron star mergers (Seto 2019), Gamma-Ray bursts (Corbet 1999), maximum angular distance from the Sun (Corbet 2003), supernovae (Tang 1976;McLaughlin 1977;Makovetskii 1980;Lemarchand 1994), pulsars (Edmondson & Stevens 2003;Vidal 2017Vidal , 2018, binary emphemerides (Pace & Walker 1975), and exoplanet transits (Filippova & Strelnitskij 1988;Arnold 2005;Kipping & Teachey 2016;Heller & Pudritz 2016;Wells et al 2018;Forgan 2019).…”

Astrometric study of Gaia DR2 stars for interstellar communication

“…This is because, it would be advantageous for receivers to inversely assess the potential criteria and strategies of senders at selecting their targets (see e.g. Schelling 1960; Wright 2018; Seto 2019).…”