Status : Blue Stragglers are stars on the main sequence found in globular clusters. They are more luminous and bluer than the main-sequence turn-off point of the cluster. The favored explanation for their unexpected location in the HR diagram is that they are binary stars, colliding or transfering mass.

Spectral type : late B - A - early F, with luminosity type IV .

Variability : Pulsating Blue stragglers are called SX Phe variables. Phenomenologically they resemble delta Sct variables. Their period is of order of 0.05 days with amplitudes smaller than 0.7 mag. Corresponding type in the GCVS : SXPHE.

-- CecileLoup - 2014-04-10