射电天文研究组知识库

Mira variables are important distance indicators owing to the clear period-luminosity relation at infrared wavelengths. We have compiled a sample of 343 Galactic Miras selected from the American Association of Variable Star Observers database and Gaia Data Release 3. We used V-band observations from the American Association of Variable Star Observers to generate template light curves and derived mean magnitudes in the near-infrared JHK band from the Two Micron All-Sky Survey. Based on the Gaia-Two Micron All-Sky Survey diagram and the Gaia-LPV2 catalog, we classified 299 O-rich and 44 C-rich Miras. We fitted the Galactic period-luminosity relations for O-rich Miras in the near-infrared JHK band and estimated slopes (-2.74 +/- 0.32, -3.14 +/- 0.30, and -3.50 +/- 0.25) and zero points (-5.58 +/- 0.06 mag, -6.40 +/- 0.06 mag, and -6.84 +/- 0.05 mag) defined at logP (days) = 2.30, separately. Although the uncertainties of our derived Galactic PLRs for Miras are still larger than those of other galaxies, the multi-band sky survey conducted using the China Space Survey Telescope could help build more reliable and accurate PLRs for Miras, particularly in a near-infrared y band (927-1,080 nm).