2025RNAAS...9...31M

Antares A is a bright ∼0.6-1.3 mag irregular/semi-regular variable M1.5 Iab star. Antares with Betelgeuse (M2.5 Iab) are the two nearest red supergiant, core-collapse Type-II supernova progenitors. Unlike Betelgeuse, Antares A has a resolved companion (B4V: Antares B) and is near its birthplace in the Upper Scorpius OB Association. We analyzed ∼70 yr of photometry mostly from the American Variable Star Observers database and Hipparcos. Due to its southern declination (-26$\mathop{.}\limits^{^\circ }$4), accurate visual photometry from mid-northern latitudes is difficult where air masses often exceed z > 3.0. As a result, Antares has fewer, generally lower quality visual-magnitude measurements. We vetted the observations, applying less weight to the visual observations made at high airmasses. The photoelectric observations were given higher weights. Period analyses were conducted utilizing the CLEANest Power-Spectrum and weighted wavelet Z-transform Wavelet programs provided in the Peranso-3 period analysis software. The results are compared to Betelgeuse.