A pulsating variable star of short period (0.04–0.2 days) that closely resembles a Delta Scuti star, although with a greater amplitude (0.3–1.2 mag. or more) and somewhat higher luminosity. The AI Velorum stars may be the older of the two groups. They are also called high-amplitude Delta Scuti stars (HADS). AI Velorum itself has a period of 0.11 days and a magnitude range of 6.2–6.8. They were once known as dwarf Cepheids, but this term is now obsolete.