Discovery of activity on Main Belt Asteroid 6993 (1995 BJ4)

@misc{clark2026discovery,
  title = {{Discovery of activity on Main Belt Asteroid 6993 (1995 BJ4)}},
  author = {Erin M. Clark and David E. Trilling and Revanth Munugala and Michael S. P. Kelley and Henry Hsieh and Michael Gowanlock and Andrew McNeill and Savannah Chappus and Maria Chernyavskaya and Graceson Mule and Gunnar Johnson and Daniel Kramer},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.31910},
  eprint = {2610.31910},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.31910},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Discovery of activity on Main Belt Asteroid 6993 (1995 BJ4)
AU  - Erin M. Clark
AU  - David E. Trilling
AU  - Revanth Munugala
AU  - Michael S. P. Kelley
AU  - Henry Hsieh
AU  - Michael Gowanlock
AU  - Andrew McNeill
AU  - Savannah Chappus
AU  - Maria Chernyavskaya
AU  - Graceson Mule
AU  - Gunnar Johnson
AU  - Daniel Kramer
PY  - 2026
DA  - 2026/10/22
PB  - arXiv
DO  - 10.48550/arxiv.2610.31910
UR  - https://arxiv.org/abs/2610.31910
AB  - We report the discovery of activity on asteroid 6993 (1995 BJ4) in the Zwicky Transient Facility (ZTF) alert stream data on UT 2026 August 5, with the help of machine learning. Visible activity can be seen as early as UT 2026 June 25. Activity on this outer-main belt object is likely not primarily driven by rotational instability, but rather is consistent with an impact event or sublimation based on several arguments. If this activity is sublimation driven, 6993 would be the largest known main belt comet (11.85 km), with the largest perihelion distance (2.853 au) and an unusually high geometric albedo of 0.166 ± 0.030. Asteroid 6993 should be monitored as it approaches perihelion in 2027 January to distinguish between activity mechanisms and understand its potential volatile inventory.
ER  -