Giant planets at small orbital distances

摘要: Using Doppler spectroscopy to detect the reflex motion of nearby star, 51 Pegasi, Mayor & Queloz (1995) claim have discovered a giant planet in 0.05 AU, 4.23 day orbit. They estimate its mass be range 0.5-2 Jupiter masses, but are not able determine nature or origin. Including effects severe stellar insolation implied, we extend theory planets recently developed encompass those at very small orbital distances. Our calculations can used help formulate search strategies for luminous tight orbits around other stars. We calculate radii and luminosities such variety compositions (H/He, He, H2O, olivine), evolutionary tracks solar-composition gas giants, geometry Hayashi forbidden zone gas-giant regime. show that stable magnitude classical Jeans evaporation photodissociation loss due EUV radiation. In addition, demonstrate quoted, well within their Roche lobes. strong composition dependence model distinctive spectral signatures provide clear diagnostics might reveal Peg B's nature, should interferometric adaptive-optics techniques ever succeed photometrically separating from star.