Water vapor on supergiants : The 12 μm texes spectra of μ cephei

摘要: Several recent papers have argued for warm, semidetached, molecular layers surrounding red giant and supergiant stars, a concept known as MOLsphere. Spectroscopic interferometric analyses often corroborated this general picture. Here we present high-resolution spectroscopic data of pure rotational lines water vapor at 12 μm the μ Cep. This star has been used to test around supergiants. Given prediction an isothermal, optically thick layer in local thermodynamic equilibrium (MOLsphere), expected be emission or least absorption but filled by from star. Our data, however, show contrary; find definite absorption. Thus, our do not easily fit into suggested isothermal MOLsphere scenario. The lines, therefore, put new, strong constraints on nature seen signatures across spectra early M We also that is even stronger than calculated standard, spherically symmetric model photosphere without any layers. A cool photosphere, representing outer layers, is, able reproduce does account 6 μm. unified Cep appears lacking. It seem necessary underlying photospheres these supergiants their whole complexity. clearly reveal inadequacies classical atmospheres.