A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space

article A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space published yes Soumyadeep Bhattacharjee author Zachary P. Vanderbosch author Mark A. Hollands author Pier-Emmanuel Tremblay author Siyi Xu author Joseph A. Guidry author J.J. Hermes author Ilaria Caiazzo author 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d0000-0002-4770-5388 Antonio C. Rodriguez author Jan van Roestel author Kareem El-Badry author Andrew J. Drake author Benjamin R. Roulston author Reed Riddle author Ben Rusholme author Steven L. Groom author Roger Smith author Odette Toloza author IlCa department White dwarfs (WDs) showing transits from orbiting planetary debris provide significant insights into the structure and dynamics of debris disks, which are eventually accreted to produce metal pollution. This is a rare class of objects with only eight published systems. In this work, we perform a systematic search for such systems within 500 pc in the Gaia-eDR3 catalog of WDs using the light curves from the Zwicky Transient Facility (ZTF) and present six new candidates. Our selection process targets the top 1% most photometrically variable sources identified using a combined variability metric from ZTF and Gaia eDR3 photometry, boosted by a metric space we define using von Neumann statistics and Pearson-Skew as a novel discovery tool to identify these systems. This is followed by optical spectroscopic observations of visually selected variables to confirm metal pollution. Four of the six systems show long-timescale photometric variability spanning several months to years, resulting either from long-term evolution of transit activity or dust and debris clouds at wide orbits. Among them, WD J1013–0427 shows an indication of reddening during the long-duration dip. Interpreting this as dust extinction makes it the first system to indicate an abundance of dust grains with radius ≲0.3 μm in the occulting material. The same object also shows metal emission lines that map an optically thick eccentric gas disk orbiting within the star’s Roche limit. For each candidate, we infer the abundances of the photospheric metals and estimate accretion rates. We show that transiting debris systems tend to have higher inferred accretion rates compared to the general population of metal-polluted WDs. Growing the number of these systems will further illuminate such comparative properties in the near future. Separately, we also serendipitously discovered an AM Canis Venaticorum showing a very long-duration outburst—only the fourth such system to be known. https://research-explorer.ista.ac.at/download/21241/21289/2025_PASP_Bhattacharjee.pdf application/pdfno IOP Publishing2025 eng Publications of the Astronomical Society of the Pacific 1538-3873 2502.0550210.1088/1538-3873/ade0ea 1377 Bhattacharjee S, Vanderbosch ZP, Hollands MA, et al. A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space. Publications of the Astronomical Society of the Pacific. 2025;137(7). doi:<a href="https://doi.org/10.1088/1538-3873/ade0ea">10.1088/1538-3873/ade0ea</a> S. Bhattacharjee et al., “A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space,” Publications of the Astronomical Society of the Pacific, vol. 137, no. 7. IOP Publishing, 2025. Bhattacharjee, Soumyadeep, et al. “A ZTF Search for Circumstellar Debris Transits in White Dwarfs: Six New Candidates, One with Gas Disk Emission, Identified in a Novel Metric Space.” Publications of the Astronomical Society of the Pacific, vol. 137, no. 7, 074202, IOP Publishing, 2025, doi:<a href="https://doi.org/10.1088/1538-3873/ade0ea">10.1088/1538-3873/ade0ea</a>. Bhattacharjee S, Vanderbosch ZP, Hollands MA, Tremblay P-E, Xu S, Guidry JA, Hermes JJ, Caiazzo I, Rodriguez AC, van Roestel J, El-Badry K, Drake AJ, Roulston BR, Riddle R, Rusholme B, Groom SL, Smith R, Toloza O. 2025. A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space. Publications of the Astronomical Society of the Pacific. 137(7), 074202. S. Bhattacharjee, Z.P. Vanderbosch, M.A. Hollands, P.-E. Tremblay, S. Xu, J.A. Guidry, J.J. Hermes, I. Caiazzo, A.C. Rodriguez, J. van Roestel, K. El-Badry, A.J. Drake, B.R. Roulston, R. Riddle, B. Rusholme, S.L. Groom, R. Smith, O. Toloza, Publications of the Astronomical Society of the Pacific 137 (2025). Bhattacharjee, S., Vanderbosch, Z. P., Hollands, M. A., Tremblay, P.-E., Xu, S., Guidry, J. A., … Toloza, O. (2025). A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space. Publications of the Astronomical Society of the Pacific. IOP Publishing. <a href="https://doi.org/10.1088/1538-3873/ade0ea">https://doi.org/10.1088/1538-3873/ade0ea</a> Bhattacharjee, Soumyadeep , Zachary P. Vanderbosch, Mark A. Hollands, Pier-Emmanuel Tremblay, Siyi Xu, Joseph A. Guidry, J.J. Hermes, et al. “A ZTF Search for Circumstellar Debris Transits in White Dwarfs: Six New Candidates, One with Gas Disk Emission, Identified in a Novel Metric Space.” Publications of the Astronomical Society of the Pacific. IOP Publishing, 2025. <a href="https://doi.org/10.1088/1538-3873/ade0ea">https://doi.org/10.1088/1538-3873/ade0ea</a>. 212412026-02-16T15:10:51Z2026-02-17T11:35:53Z