Searching for new variable white dwarfs: The discovery of the three new pulsating and three new binary systems

L. Antunes AmaralM. VučkovićI. PelisoliA. IstrateS. O. KeplerJ. M. Hibbert2026-02-242026-02-242025-0210.1051/0004-6361/202453308https://cris-uv-2.scimago.es/handle/123456789/8505In recent years, approximately 150 low-mass white dwarfs (WDs), typically with masses below 0.4 M⊙, have been discovered. Observational evidence indicates that most of these low-mass WDs are in binary systems, supporting binary evolution scenarios as their primary formation pathway. A few extremely low-mass (ELM) WDs in this population have also been found to be pulsationally variable. In this work we present a comprehensive analysis aimed at identifying new variable low-mass WDs. From our candidate selection, 16 objects were identified as being within the ZZ Ceti instability strip. Those objects were observed over multiple nights using high-speed photometry from the SOAR/Goodman and SMARTS-1 m telescopes. Our analysis led to the discovery of three new pulsating WDs: one pulsating ELM WD, one low-mass WD, and one ZZ Ceti star. Additionally, we identified three objects in binary systems, two with ellipsoidal variations in their light curves (one of which is likely a pre-ELM star) and a third that shows a reflection effect.Searching for new variable white dwarfs: The discovery of the three new pulsating and three new binary systemsjournal-article