Chandra X-ray Detection Confirms Accretion-Driven Outbursts in LBV Binary AT 2016blu
The study establishes AT 2016blu as a high-mass X-ray binary where a luminous blue variable transfers mass to a compact companion at periastron, powering repeated outbursts. This mechanism links LBV variability directly to supernova progenitor channels through binary interaction. The result reframes SN impostors as potential precursors to systems like SN 2010da rather than isolated stellar events.
Chandra observations in March 2026 captured five epochs of X-ray emission from AT 2016blu in NGC 4559, absent in stacked 2001-2002 archival data. The source, a ≥33 solar mass LBV, exhibits ~113-day quasiperiodic visual outbursts consistent with eccentric binary periastron passages. Measured luminosity and implied accretion rate ≥8×10^{-8} M_⊙ yr^{-1} match expectations for mass transfer onto a compact object rather than intrinsic stellar instability. This marks the first direct evidence linking LBV impostor eruptions to binary accretion.
Aghakhanloo et al.: Next predicted periastron in late 2026 will produce another X-ray detection above 10^38 erg s^{-1} if accretion model is correct.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2608.20469)
- [2]Supporting Source(https://arxiv.org/abs/2003.11039)