Friedrich Otto Krone

Periodic optical variability of the known white dwarf WD J2101+2935

A research note reporting periodic optical variability of the known DC white dwarf WD J2101+2935 (Gaia DR3 1846405001739893376). Original ZTF photometry and independently acquired Pan-STARRS images support a preferred photometric repetition period of approximately 71.3153 minutes...

A Candidate Outburst of the Cool ZZ Ceti Star LP 119-10 in Archival TESS and ZTF Photometry

LP 119-10 (WD 0502+540, TIC 252385237) is a known hydrogen-atmosphere pulsating white dwarf (ZZ Ceti star, DAV) near the cool edge of the instability strip. This preprint reports a single brightening event found in archival TESS 120-s photometry of sector 86. On 2024 December 4 t...