MYRESEARCH
We conducted a benchmarking analysis of the semi-regular pulsator and red supergiant α Ori. In its dimming episode last 2020, our observational results include the binned measurements from the space-based telescope SMEI collated. We report a long secondary period of PLSP = 2350 ± 10 d and a fundamental pulse of P0 = 415 d ± 30 d for the interest. Meanwhile, we also detected the first overtone component of 185 ± 10 d which supports the current literature's standing for this newly acquired pulse. At ∼2.20 ± 0.10 μm, we acquired Near-Infrared K-band photometric measurements from several catalogues and surveys in accordance of the calibration. Our assigned inherent color plays at the middle of the extremes from existing literature. Likewise, we attained a weighted excess color index of E(B−V) = 0.340 and using a K-extinction factor of RK = 0.382 yields to an extinction of AK = 0.130. By subtracting extinction to all K-band photometry, using the linearity, and newly-derived distance from previous literatures, our effort results to a log(L/L⊙) = 5.00 ± 0.15 (+0.48, −0.45) for α Ori. In turn, this allowed us to conduct the benchmarking scheme alongside the data from existing reports that are stitched together using period-luminosity relationship. This results to a best-fit of log(L/L⊙) = 7.26 ± 0.10 × log Ρ + (-14.10 ± 0.25) which reveals that α Ori can be situated into the lower bound 18 M⊙ regime caused by the current pulsation trends.
This is the first case study conducted and related to a tornadic event in the Philippines. An extensive ground-relative, mesoscale, synoptic, and dynamic analyses was constructed to understand the cause of Manila Tornado development, which occurred at 14th of August 2016 and rated in Enhanced Fujita (EF) Scale as an EF1. Prior to the tornado occurrence, the tropospheric environment over Luzon resembles to an efficient convection process; a surface inverted trough along with the common monsoonal flow induced convergence and instability along the western Luzon and divergence aloft caused by an upper-level ridge. Along a typical tropic set up over the aforementioned area, the surface was moist and the warm buoyant air parcels managed to tap along the prime environment, especially at the peak of convective heating. A tornadic mini-supercell TSTM developed in the area of potentially unstable atmosphere with undiluted Convective Available Potential Energy (CAPE) ≥ 1750 J kg-1 and low-level CAPE ≥ 200 J kg-1 in both 00 and 12 UTC Tanay soundings. Without capping, this instigated a stout updraft that can withstand environmental entrainment and realize the available buoyancy by 70 to 80%. The updraft column also gained rotation because of the kinematics in place with ample and near-pure streamwise vorticity close to the ground accompanied in the substantial Storm-Relative Helicity (SRH) indices. This caused a tornado to occur from 0830 to 09 UTC 14 August 2016. When compared to the established U.S. baseline climatology, the Manila Tornado’s cumulative vertical profile is within the distribution norms associated with tornadic supercell environmental setups. This study showed that tornadic event in Manila was caused by a combination of; (a) Potential vorticity (PV) anomaly and possible ducted waves, which increased vorticity over the Metropolis, (b) Kinematic support due to the curved hodographs and wind profile, and (c) Thermodynamic instability that triggered the severe TSTM and tilted the vortex into vertical.