We present a revised distance to the nearby galaxy NGC 6822 using a new multi-band fit to both previously published and new optical, near-, and mid-infrared data for Cepheid variables. The new data presented in this study include multi-epoch observations obtained in 3.6 μm and 4.5 μm with the Spitzer Space Telescope taken for the Carnegie Hubble Program. We also present new observations in J, H, and Ks with FourStar on the Magellan Baade Telescope at Las Campanas Observatory. We determine mean magnitudes and present new period-luminosity relations in V, I, J, H, Ks , Infrared Array Camera 3.6 μm, and 4.5 μm. In addition to using the multi-band distance moduli to calculate extinction and a true distance, we present a new method for determining an extinction-corrected distance modulus from multi-band data with varying sample sizes. We combine the distance moduli and extinction for individual stars to determine E(B-V) = 0.35 ± 0.04 and a true distance modulus μ o = 23.38 ± 0.02stat ± 0.04sys.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science