Blue Straggler Stars: Early Observations that Failed to Solve the Problem

TL;DR

This paper reviews early observations and ideas about blue straggler stars from their discovery in 1953 until 1992, highlighting failed attempts to resolve their origins.

Contribution

It compiles and analyzes historical data and hypotheses on blue stragglers, emphasizing the unresolved nature of their origins prior to 1992.

Findings

Early observations identified anomalous blue stars in globular clusters.

Multiple hypotheses were proposed but none conclusively explained blue straggler origins.

The chapter summarizes the state of knowledge up to the early 1990s.

Abstract

In this chapter, I describe early ideas on blue stragglers, and various observations (some published, some not) that promised but failed to resolve the question of their origin. I review the data and ideas that were circulating from Allan Sandage's original discovery in 1953 of "anomalous blue stars" in the globular cluster M3, up until about 1992, when what seems to have been the only previous meeting devoted to Blue Straggler Stars (BSSs) was held at the Space Telescope Science Institute.