GP Andromedae (often abbreviated to GP And) is a Delta Scuti variable star in the constellation Andromeda. It is a pulsating star, with its brightness varying with an amplitude of 0.55 magnitudes around a mean magnitude of 10.7.
System GP Andromedae is a main sequence Population I star of spectral type A3, placing it in the instability strip of the Hertzsprung-Russell diagram where Delta Scuti variables lay.
A visual companion star 11 arcseconds away, named TYC 1739-1526-2, shares a common proper motion and has a similar distance (measured by parallax) as GP Andromedae. There is no proof, however, that the two stars are gravitationally bound.
Variability The observed variability of GP Andromedae is typical for a Delta Scuti variable; it's a purely monoperiodic radial pulsating star with a period of 0.0787 days. The period of pulsations is slowly and continuously increasing, matching the predictions of stellar evolution models for Delta Scuti variables.
References GP And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2018-10-17.