# The Drake Equation as a Function of Spectral Type and Time

## TL;DR

This paper explores how the likelihood and longevity of communicative civilizations in the galaxy depend on star spectral types and galactic age, suggesting F- and G-dwarfs are prime search targets.

## Contribution

It models the Drake equation parameters as functions of spectral type and galactic time, providing new insights into where and when civilizations might emerge and persist.

## Key findings

- F- and G-dwarf stars are optimal for searching for civilizations.
- Civilization lifetimes vary with spectral type and galactic age.
- The emergence of civilizations is influenced by stellar and galactic evolution.

## Abstract

This chapter draws upon astronomical observations and modeling to constrain the prevalence of communicative civilizations in the galaxy. We discuss the dependence of the Drake equation parameters on the spectral type of the host star and the time since the galaxy formed, which allow us to examine trajectories for the emergence of communicative civilizations over the history of the galaxy. We suggest that the maximum lifetime of communicative civilizations depends on the spectral type of the host star, which implies that F- and G-dwarf stars are the best places to search for signs of technological intelligence today.

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Source: https://tomesphere.com/paper/1705.07816