V1224 Cas - an EL CVn-type Eclipsing Binary Consisting of a Helium White Dwarf Precursor and a Delta Scuti Pulsator

Understand

We report the discovery of a new eclipsing EL CVn-type binary, consisting of a $\delta$ Sct-type pulsator and a thermally bloated low-mass pre-He white dwarf (WD).

• Spectroscopy and time-series $BV$ photometry of V1224 Cas were carried out.
• The spectroscopy reveals a spectral type of A3 for the star.
• Light-curve modelling indicate that V1224 Cas is a short-period detached system containing a possible low-mass WD with an effective temperature of about 9516 K.