Evans, Nancy RemageGallenne, AlexandreKervella, PierreMérand, AntoineMonnier, JohnAnderson, Richard IGünther, H. MoritzProffitt, CharlesWinston, Elaine M.Pietrzynski, GrzegorzGieren, WolfgangKuraszkiewicz, JoannaAnugu, NarsireddyRoettenbacher, Rachael M.Lanthermann, CyprienGutierrez, MayraSchaefer, GailSetterholm, Benjamin R.Ibrahim, NouraKraus, Stefan2024-09-172024-09-172024-09Astrophysical Journal Open Access Volume 972, Issue 21 September 2024 Article number 1450004637Xhttps://repositorio.unab.cl/handle/ria/60247Indexación: Scopus.The Cepheid AW Per is a component in a multiple system with a long-period orbit. The radial velocities of Griffin cover the 38 yr orbit well. An extensive program of interferometry with the Center for High Angular Resolution Astronomy array is reported here, from which the long-period orbit is determined. In addition, a Hubble Space Telescope high-resolution spectrum in the ultraviolet demonstrates that the companion is itself a binary with nearly equal-mass components. These data combined with a distance from Gaia provide a mass of the Cepheid (primary) of M 1 = 6.79 ± 0.85 M ⊙. The combined mass of the secondary is M S = 8.79 ± 0.50 M ⊙. The accuracy of the mass will be improved after the fourth Gaia data release, expected in approximately two years.enAstrophysical Journal Open Access Volume 972, Issue 21 September 2024 Article number 145The Orbit and Mass of the Cepheid AW PerArtículoCC BY 4.0 Attribution 4.0 International10.3847/1538-4357/ad5e7d