We show that the optical flare event discovered by Graham et al. (2020) towards the active galactic nucleus J1249+3449 is fully consistent with being a quasar microlensing event due to a $simeq 0.1 M_{odot}$ star, although other explanations, such as that, mainly supported by Graham et al. (2020), of being the electromagnetic counterpart associated to a binary black hole merger, cannot be completely excluded at present.
تحميل البحث