This study presents the multiwavelength investigation of the absolute magnitudes and colors of the red clump (RC) stars selected from APOGEE and GALAH DR2 combined catalog which is complemented with Gaia DR2 astrometric data and multiwavelength photometric data of GALEX GR6/7, SDSS DR7, Gaia DR2, 2MASS, and WISE sky surveys. The analyses are centered on the different distance estimation methods using Gaia trigonometric parallaxes, (1/ϖ) and Bayes statistics, and chemically defined Galactic disk populations on [α/Fe] × [Fe/H] plane. This investigation questions the long-studied problem of the population effects on RC luminosity. Using two different distance estimation approaches, (i) chemical thin and chemical thick disk RC stars are shown to have different absolute magnitudes, while colors remain the same in all photometric bands. Absolute magnitudes vary between −0.12 and +0.13 mag for the 1/ϖ with the change of the Galactic population. This variation in absolute magnitudes is found to be larger for the other method, (ii) the Besançon population synthesis model of Galaxy for 2MASS photometry, in which the absolute magnitude difference between chemical populations were found between −0.35 and −0.40 mag from thin disk to thick disk. When results compared with each other, differences of absolute magnitudes are about three times larger in the model than in the observations. We confirm that the RC absolute magnitudes depend on α-element abundances of Galactic populations.

We estimated iron and metallicity gradients in the radial and vertical directions with the F and G type dwarfs taken from the Radial Velocity Experiment Data Release 4 database. The sample defined by the constraints Z_max ⩽ 825 pc and e_p ⩽ 0.10 consists of stars with metal abundances and space velocity components agreeable with the thin-disc stars. The radial iron and metallicity gradients estimated for the vertical distance intervals 0 < Z_max ⩽ 500 and 500 < Z_max ⩽ 800 pc are $\text{d}[\text{Fe}/\text{H}]/\text{d}R_{\rm m}=-0.083\pm 0.030$ and $\text{d}[\text{Fe}/\text{H}]/\text{d}R_{\rm m}=-0.048\pm 0.037$ dex kpc⁻¹, and $\text{d}[\text{M}/\text{H}]/\text{d}R_{\rm m}=-0.063\pm 0.011$ and $\text{d}[\text{M}/\text{H}]/\text{d}R_{\rm m}=-0.028\pm 0.057$ dex kpc⁻¹, respectively, where R_m is the mean Galactocentric distance. The iron and metallicity gradients for less number of stars at further vertical distances, 800 < Z_max ⩽ 1500 pc, are mostly positive. Compatible iron and metallicity gradients could be estimated with guiding radius (R_g) for the same vertical distance intervals 0 < Z_max ⩽ 500 and 500 < Z_max ⩽ 800 pc, i.e. $\text{d}[\text{Fe}/\text{H}]/\text{d}R_{\rm g}=-0.083\pm 0.030$ and $\text{d}[\text{Fe}/\text{H}]/\text{d}R_{\rm g}=-0.065\pm 0.039$ dex kpc⁻¹; $\text{d}[\text{M}/\text{H}]/\text{d}R_{\rm g}=-0.062\pm 0.018$ and $\text{d}[\text{M}/\text{H}]/\text{d}R_{\rm g}=-0.055\pm 0.045$ dex kpc⁻¹. F and G type dwarfs on elongated orbits show a complicated radial iron and metallicity gradient distribution in different vertical distance intervals. Significant radial iron and metallicity gradients could be derived neither for the sub-sample stars with R_m ⩽ 8 kpc, nor for the ones at larger distances, R_m > 8 kpc. The range of the iron and metallicity abundance for the F and G type dwarfs on elongated orbits, [−0.13, −0.01), is similar to the thin-disc stars, while at least half of their space velocity components agree better with those of the thick-disc stars. The vertical iron gradients estimated for the F and G type dwarfs on circular orbits are $\text{d}[\text{Fe}/\text{H}]/\text{d}Z_{{\rm max}}=-0.176\pm 0.039$ dex kpc⁻¹ and $\text{d}[\text{Fe}/\text{H}]/\text{d}Z_{{\rm max}}=-0.119\pm 0.036$ dex kpc⁻¹ for the intervals Z_max ⩽ 825 and Z_max ⩽ 1500 pc, respectively.

We present a multimethod investigation of four metal-poor G-type main-sequence stars to resolve their Galactic origins. By combining high-resolution spectroscopy from PolarBase, photometric/astrometric data from Gaia DR3, and spectral energy distribution modeling, we derive precise stellar parameters, chemical abundances, kinematics, and Galactic orbital parameters. The stars HD 22879, HD 144579, HD 188510, and HD 201891 show effective temperatures of 5855 ± 110, 5300 ± 160, 5370 ± 60, and 5880 ± 90 K; surface gravities of 4.40 ± 0.18, 4.52 ± 0.37, 4.57 ± 0.13, and 4.48 ± 0.18 cgs; and metallicities of −0.86 ± 0.08, −0.55 ± 0.12, −1.60 ± 0.07, and −1.15 ± 0.07 dex, respectively. Kinematic analysis suggests that HD 22879, HD 144579, and HD 201891 are potential bulge-origin escapees, possibly ejected by the Galactic bar or spiral arm perturbations. HD 188510, however, shows halo-like dynamics, including a retrograde orbit. Chemical abundance trends ([α/Fe] versus [Fe/H]) reveal mixed origins, challenging kinematic classifications. This discrepancy highlights the importance of integrative methodologies in Galactic archaeology. We associate HD 22879, HD 144579, and HD 201891 with the bulge globular cluster NGC 6441, NGC 5927, and NGC 6544, respectively. HD 188510’s retrograde motion and low metallicity align with ejection from the halo globular cluster NGC 5139 (ω Cen). These results illustrate the complex interplay of dynamical processes—including bar resonances, spiral arm perturbations, and tidal stripping—in depositing metal-poor stars into the solar neighborhood.