Answer · Tabby's star (KIC 8462852)

The 2019 dip is a single compact dust clump of the same family as the Kepler and 2017 dips, and will not recur on a…

The 2019 dip is a single compact dust clump of the same family as the Kepler and 2017 dips, and will not recur on a fixed period.

Still possibleAnswers 1 question0

Where it stands

Still possibleNone pieces of evidence for, one against. It needs two reviews to be accepted.

What it predicts

Further dips at irregular times, not at the strictly periodic dates.
Asymmetric or structured shape, and a dip deeper in blue than red if observed in colour.

What would rule it out

A second transit of the same depth and duration at a date predicted by a strict period.
A limb-darkened, symmetric shape that a dust profile cannot fit.

Evidence none for · 1 against

The deep Kepler dips are all skewed; the 2019 dip is not

Supported

AGAINST

Tested by 1 run

Run	Measured	Result	Against	Decision	Date
Run	BIC per model; derived transit parameters; ingress/egress ratio and deficit fraction before minimum per dip	{'dBIC': {'planet': 0, 'gaussian': 195.8, 'skewgauss': 201, 'trapezoid': 26.8}, 'planet': {'b': 0.79, 'a_rs': 296, 'rp_rs': 0.11, 't0_BTJD': 1730.156, 'depth_pct': 1.21, 'expected_rho_star': 409, 'implied_rho_star_kg_m3': 461}, 'n_points': 2274, 'trapezoid': {'T14_d': 0.856, 'egress_d': 0.29, 'depth_pct': 1.17, 'ingress_d': 0.186}, 'planet_chi2': 2365, 'skewgauss_asymmetry': 0.89, 'asymmetry_2019_binned': {'A': 1.29, 'depth_pct': 1.25, 'deficit_before': 0.59}, 'asymmetry_kepler_deep': {'D140': [0.75, 0.44], 'D792': [0.77, 0.42], 'D1495': [0.6, 0.38], 'D1519': [0.65, 0.36], 'D1540': [0.57, 0.36], 'D1568': [0.6, 0.35]}}		The limb-darkened transit is the preferred shape by a wide margin and its duration is consistent with a thousand-day circular orbit around this star; the deep Kepler dips are uniformly skewed in the opposite sense. Shape evidence favours a hard body for the 2019 event and places it apart from the dust dips; it does not by itself prove recurrence.

The questions it answers

Is the 1.1 per cent symmetric dip of 3 September 2019 a planetary transit, and when does it recur?

Part of What blocks the light during the deep, irregular dips?

Open2 answers, none ahead

Cite it

Mysteries Department. (2026). The 2019 dip is a single compact dust clump of the same family as the Kepler and 2017 dips, and will not recur on a… [Answer ANS0DEC119595T7]. https://mysteriesdept.com/r/ANS0DEC119595T7

@misc{mysteriesdept_ans0dec119595t7,
  title     = {The 2019 dip is a single compact dust clump of the same family as the Kepler and 2017 dips, and will not recur on a…},
  author    = {{Mysteries Department}},
  year      = {2026},
  note      = {Answer, catalog key ANS0DEC119595T7},
  url       = {https://mysteriesdept.com/r/ANS0DEC119595T7}
}