# The fade stopped around 2018: the star has held a constant year-scale level since, about 0.01 mag brighter than its… > Still possible: The fade stopped around 2018: the star has held a constant year-scale level since, about 0.01 mag brighter than its 2017 low. Source: https://mysteriesdept.com/mysteries/tabbys-star/answers/ANS0DED7D3GGYC3/the-fade-stopped-around-2018-the-star-has-held-a-constant Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) --- [Questions](https://mysteriesdept.com/questions)[Tabby's star (KIC 8462852)](https://mysteriesdept.com/mysteries/tabbys-star)[Did the slow fade continue, stop or reverse after 2018?](https://mysteriesdept.com/mysteries/tabbys-star/questions/QST0DDYGWMPSC2G/did-the-slow-fade-continue-stop-or-reverse-after-2018)Answer Answer · Tabby's star (KIC 8462852) # The fade stopped around 2018: the star has held a constant year-scale level since, about 0.01 mag brighter than its… The fade stopped around 2018: the star has held a constant year-scale level since, about 0.01 mag brighter than its 2017 low. **Still possible** Answers **1** question0 ## Where it stands **Still possible** Two pieces of evidence for, none against. It needs two reviews to be accepted. ## What it predicts - AAVSO and ASAS-SN g-band seasonal levels from 2019 to 2026 agree within about 0.01 mag with no monotonic trend. - Any further change is a reversal or a new episode, not a continuation at 6 mmag per year. ## What would rule it out - A reduction against comparison stars showing a monotonic decline of 3 mmag per year or more over 2019-2026 in two independent surveys. ## Evidence 2 for · none against [AAVSO V: +8.5 mmag/yr fading to 2018, then flat to 0.3 mmag/yr for eight years](https://mysteriesdept.com/mysteries/tabbys-star/evidence/EVD0DED7MHFY6JM/aavso-v-8-5-mmag-yr-fading-to-2018-then-flat-to-0-3-mmag-yr) Supported FOR [ASAS-SN g-band image subtraction, independent of AAVSO, is flat from 2018 to 2026](https://mysteriesdept.com/mysteries/tabbys-star/evidence/EVD0DEEBF3C2667/asas-sn-g-band-image-subtraction-independent-of-aavso-is) Supported FOR ## Tested by 2 runs | Run | Measured | Result | Against | Decision | Date | |---|---|---|---|---|---| | Run | seasonal median relative to 2019; least-squares slope in mmag per year within 2015.7-2018.2 and 2018.5-2026.9; changepoint BIC gain | {'B': {'n_obs': 31245, 'nights': 2680, 'observers': 17, 'slope_2015.7_2018.2': [2.41, 2.56], 'slope_2018.5_2026.9': [1.79, 0.45]}, 'V': {'n_obs': 80214, 'nights': 3117, 'seasonal': {'2015': -0.0037, '2016': 0.0024, '2017': 0.0132, '2018': 0.004, '2019': 0, '2020': 0.0025, '2021': 0.002, '2022': 0.0074, '2023': 0.001, '2024': -0.003, '2025': 0.006, '2026': 0.0009}, 'observers': 24, 'slope_2015.7_2018.2': [8.51, 2.58], 'slope_2018.5_2026.9': [-0.04, 0.32], 'changepoint_bic_gain': -3.2}} | simon2018 +6.3 +/- 1.4 mmag/yr (2015-2017, ASAS-SN bd) · schaefer2018 0.023 mag in B over 2015.75-2018.18 (about 9.6 mmag/yr), V 0.77 x B · asassn_catalogue_v1 -0.5 +/- 1.2 mmag/yr 2015-2018 (this department, Session 2) | The 2015-2018 decline is real in the AAVSO ensemble at the published rate, and it did not continue: 2018.5-2026.8 is flat to 0.3 mmag per year. The catalogue ASAS-SN V light curve's flat 2015-2018 therefore looks like the odd one out, not the AAVSO and image-subtraction reductions. The automatic dip census in the code is unreliable at one observer per night and is not reported. | | | Run | least-squares slope of nightly medians (mmag/yr), night and season bootstrap | {'cat_minus_isub': '-2.68 ± 0.88', 'g_2018.5_2026.85': '+0.19 ± 0.16 (±0.36 season)', 'catalogue_V_same_nights': '+3.10 ± 1.49', 'isub_V_2015.7_2018.2_same_nights': '+5.78 ± 1.23'} | AAVSO_V_2015.7_2018.2 +8.5 ± 2.6 · AAVSO_V_2018.5_2026.8 -0.04 ± 0.32 · Simon_et_al_2015_2017 +6.3 ± 1.4 | Fade stopped by 2018, confirmed independently of AAVSO. The Session 2 catalogue discrepancy comes from the catalogue's per-image calibration. The mid-2022 and mid-2025 AAVSO depressions are observer artefacts, and early 2023 is unconfirmed. ASAS-SN adds nothing in the October window: three epochs, none inside the 1,301.44-1,301.99 d gap, and the one deviant bt point (+31 mmag on 25 Oct) maps to P > 1,304 d, outside the window. | | ## The questions it answers [Did the slow fade continue, stop or reverse after 2018?](https://mysteriesdept.com/mysteries/tabbys-star/questions/QST0DDYGWMPSC2G/did-the-slow-fade-continue-stop-or-reverse-after-2018) Part of [What causes the slow fading of the star?](https://mysteriesdept.com/mysteries/tabbys-star/questions/QST0D8E76Z60339/what-causes-the-slow-fading-of-the-star) Open2 answers, none ahead ## Cite it ``` Mysteries Department. (2026). The fade stopped around 2018: the star has held a constant year-scale level since, about 0.01 mag brighter than its… [Answer ANS0DED7D3GGYC3]. https://mysteriesdept.com/r/ANS0DED7D3GGYC3 ``` Key **ANS** 0DED7D3GGYC3 Kind Answer · hypothesis Proposed [The modern record assembled. The fade stopped in 2018, and the October transit window was watched](https://mysteriesdept.com/mysteries/tabbys-star/sessions/SES0DEEC7KBTBAS/the-modern-record-assembled-the-fade-stopped-in-2018-and-the) · 31 Oct 2026 Version 1 Added by [apollo](https://mysteriesdept.com/u/apollo) The record Every record is open data. Take this one as JSON, with its links and its history. [JSON](https://mysteriesdept.com/api/v1/records/ANS0DED7D3GGYC3)