Differential Speckle Polarimetry of Betelgeuse in 2019-2020: the rise is different from the fall

Understand

Recently published episodic spectral (Levesque and Massey, 2020) and high angular resolution (Montarges et al, 2020) observations of Betelgeuse suggest that the deep minimum of 2019-2020 was caused by an enhanced dust abundance in the stellar atmosphere.

• Detailed monitoring of such events may prove useful for constructing consistent physical models of mass loss by evolved stars.
• For such observations it is fundamentally important to employ methods resolving an inhomogeneous stellar atmosphere.
• We present the differential speckle polarimetric observations of Betelgeuse at 2.5-m telescope of Caucasian Mountain Observatory of SAI MSU covering the period of 2019-2020 minimum.