Method · photometry

Modern V light-curve stitch 2006-2026: ASAS, ASAS-SN, AAVSO tied on their overlaps

To show the whole post-2006 history of the slow changes on one scale, and to set it beside the dip episodes.

PhotometryVersion 1.0Licence MIT1 runUsed on 1 mystery

Questions it answers

What causes the slow fading of the star?

Code Python

Download module (.py)stitch_modern.pyView source

Runs and results 1 run

Run	Mystery	Measured	Result	Against	Date
RUN0DFQ2NQVEE44	Tabby's	Seasonal median V on the ASAS-SN V scale (mmag relative to the 2007 season)	{'flat_2019_2026': 'within about 5 mmag', 'fade_2010_to_2013': '+47 ± 5', 'fade_2015_to_2018': 'about +10', 'recovery_2013_to_2015': '-34 ± 7', 'tie_rms_g_vs_aavso_mmag': 4}	Simon2018 brightenings 2007 and 2014, fade 6.3 mmag/yr 2015-2017 · Montet2016_Kepler about 3% fade 2009-2013

Applied to

Tabby's star (KIC 8462852)

4 datasetsAAVSO International Database export for KIC 8462852, 1 July 2018 to 29 October 2026 (77,195 observations, with comparison stars), AAVSO International Database export for KIC 8462852, October 2015 to June 2018 (66,875 observations, with comparison stars), ASAS V photometry of KIC 8462852, 2006-2017 (Simon et al. 2018, full table), ASAS-SN v1 image-subtraction light curve of KIC 8462852, 2015-2026 (V and g)

References

ASAS-SN 2015-2017: fade of 6.3 +/- 1.4 mmag per year, more extreme than 99.4 per cent of 1,078 comparison stars; ASAS V 2006-2017 shows brightening 2006-07, dimming 2009-13 (15.8 +/- 1.5 mmag/yr) and brightening around 2014, so a straight line is a poor description. The modern-era reference for the fade's non-monotonic history.