High Precision, Directly Determined Radii and Effective Temperatures for Giant Stars

研究人员计划使用光学干涉测量法显著改进对恒星温度和恒星半径的测量，425颗巨星的距离是通过最近对伊帕科斯数据集的重新分析准确确定的。通过直接测量有效温度、线性半径和肢体暗化，间接预测这些值的模型将被校准。他们将使用来自Palomar试验台干涉仪(PTI)和海军光学干涉仪(NOI)的角尺寸数据，结合分光光度法直接确定巨型恒星的温度、半径和恒星结构，精度达到前所未有的水平。光学和近红外数据将被用来限制辐射热通量，结合PTI角直径将提供直接的温度测量。这项工作将对恒星天体物理的许多领域产生更广泛的影响，包括结构、建模、演化、银河系光谱合成、行星际科学和行星/恒星形成理论。他们还将与洛厄尔天文台一起参加一项公共宣传计划。

The investigators plan to significantly improve measurements of stellar temperatures and radii using optical interferometry of 425 giant stars, whose distances are accurately determined from a recent reanalysis of the Hipparcos dataset. Through direct measurements of effective temperature, linear radius and limb darkening, models that indirectly predict such values will be calibrated. They will use angular size data from the Palomar Testbed Interferometer (PTI) and Navy Optical Interferometer (NOI) in conjunction with spectrophotometry to directly determine temperature, radius, and stellar structure for the giant stars at unprecedented levels of accuracy. Optical and nearinfrared data will be used to constrain the bolometric fluxes, which in combination with PTI angular diameters will provide direct measures of temperature. This work will have broader impacts to many fields of stellar astrophysics, including structure, modeling, evolution, galactic spectral synthesis, exoplanetary science and planet/star formation theory. They will also participate in a public outreach program with Lowell Observatory.