Incidental discovery of a relatively bright Delta Scuti Variable
Discovery during an exoplanet observation that the magnitude 9.8 star HD 252752 is a Delta Scuti variable star .
While choosing appropriate comparison stars for an exoplanet transit of the star KELT-2 A, an AAVSO-approved (believed to be stable) star exhibited significant and abrupt variations in magnitude, plotted below as relative flux T1.
It turned out to be a previously undiscovered brighter (Magnitude 9.86) Delta Scuti variable star, HD 252752.
Delta Scuti variables are pulsating stars that show small, rapid changes in brightness due to the pulsation of their outer layers. They have pulsation periods of a few hours to a few days and variations in brightness of a few hundredths to a few tenths of a magnitude. Delta Scuti variables are young, relatively hot stars with masses ranging from 1.5 to 2.5 times that of the Sun.
Spectrographic and photometric observations of these stars provide insights into stellar evolution, oscillations, and the formation of multiple star systems.