H. DawsonS. GeierU. HeberI. PelisoliM. DorschV. SchaffenrothN. ReindlR. CulpanM. PritzkuleitJ. VosA. A. SoemitroM. M. RothD. SchneiderM. UzundagVuckovic, MajaMajaVuckovicL. Antunes AmaralA. G. IstrateS. JusthamR. H. ØstensenJ. H. TeltingA. A. DjupvikR. RaddiE. M. GreenC. S. JefferyS. O. KeplerJ. MundayT. SteinmetzT. Kupfer2025-12-072025-12-072024-05-2710.1051/0004-6361/202348319https://cris-uv-2.scimago.es/handle/123456789/7382<jats:p>We present the first volume-limited sample of spectroscopically confirmed hot subluminous stars out to 500 pc, defined using the accurate parallax measurements from the <jats:italic>Gaia</jats:italic> space mission data release 3 (DR3). The sample comprises a total of 397 members, with 305 (~77%) identified as hot subdwarf stars, including 83 newly discovered systems. Of these, we observe that 178 (~58%) are hydrogen-rich sdBs, 65 are sdOBs (~21%), 32 are sdOs (~11%), and 30 are He-sdO/Bs (~10%). Among them, 48 (~16%) exhibit an infrared excess in their spectral energy distribution fits, suggesting a composite binary system. The hot subdwarf population is estimated to be 90% complete, assuming that most missing systems are these composite binaries located within the main sequence (MS) in the <jats:italic>Gaia</jats:italic> colour-magnitude diagram. The remaining sources in the sample include cataclysmic variables, blue horizontal branch stars, hot white dwarfs, and MS stars. We derived the mid-plane density <jats:italic>ρ</jats:italic><jats:sub>0</jats:sub> and scale height h<jats:sub><jats:italic>z</jats:italic></jats:sub> for the non-composite hot subdwarf star population using a hyperbolic sechant profile (sech<jats:sup>2</jats:sup>). The best-fit values are <jats:italic>ρ</jats:italic><jats:sub>0</jats:sub> = 5.17 ± 0.33 × 10<jats:sup>−7</jats:sup> stars pc<jats:sup>−3</jats:sup> and h<jats:sub><jats:italic>z</jats:italic></jats:sub> = 281 ± 62 pc. When accounting for the composite-colour hot subdwarfs and their estimated completeness, the mid-plane density increases to <jats:italic>ρ</jats:italic><jats:sub>0</jats:sub> = 6.15<jats:sub>−0.53</jats:sub><jats:sup>+1.16</jats:sup> × 10<jats:sup>−7</jats:sup> stars pc<jats:sup>−3</jats:sup>. This corrected space density is an order of magnitude lower than predicted by population synthesis studies, supporting previous observational estimates.</jats:p>journal-article