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A VI Wesenheit diagram featuring SX Phoenicis, delta Scuti, RR Lyrae, type II and classical Cepheid variables is calibrated by means of geometric-based distances inferred from HST, Hipparcos, and VLBA observations (n=30). The distance to a target population follows from the offset between the observed Wesenheit magnitudes and the calibrated template. The method is evaluated by ascertaining the distance moduli for the LMC (mu_0=18.43+-0.03 se) and the globular clusters omega Cen, M54, M13, M3, and M15. The results agree with estimates cited in the literature, although a nearer distance to M13 is favoured (pending confirmation of the datas photometric zero-point) and observations of variables near the core of M15 suffer from photometric contamination. The calibrated LMC data is subsequently added to the Wesenheit template since that galaxy exhibits precise OGLE photometry for innumerable variables of differing classes, that includes recent observations for delta Scuti variables indicating the stars follow a steeper VI Wesenheit function than classical Cepheids pulsating in the fundamental mode. VI photometry for the calibrators is tabulated to facilitate further research, and includes new observations acquired via the AAVSOs robotic telescope network (e.g., VY Pyx: <V>=7.25 and <V>-<I>=0.67). The approach outlined here supersedes the lead authors prior first-order effort to unify variables of the instability strip in order to establish reliable distances.
Dark matter phenomena in rotationally supported galaxies exhibit a characteristic acceleration scale of $g_dagger approx 1.2times 10^{-10}$ m s$^{-2}$. Whether this acceleration is a manifestation of a universal scale, or merely an emergent property
We analyze the near-infrared to UV data of 16 quasars with redshifts ranging from 0.71 $<$ $z$ $<$ 2.13 to investigate dust extinction properties. The sample presented in this work is obtained from the High $A_V$ Quasar (HAQ) survey. The quasar candi
We present new distance determinations to the nearby globular M4 (NGC~6121) based on accurate optical and Near Infrared (NIR) mean magnitudes for fundamental (FU) and first overtone (FO) RR Lyrae variables (RRLs), and new empirical optical and NIR Pe
The angular size of the broad line region (BLR) of the nearby active galactic nucleus (AGN) NGC 3783 has been spatially resolved by recent observations with VLTI/GRAVITY. A reverberation mapping (RM) campaign has also recently obtained high quality l
The current tension between the direct and the early Universe measurements of the Hubble Constant, $H_0$, requires detailed scrutiny of all the data and methods used in the studies on both sides of the debate. The Cepheids in the type Ia supernova (S