Effective temperatures of early-type supergiants are important to test stellar atmosphere- and internal structure-models of massive and intermediate mass objects at different evolutionary phases. However, these Teff values are more or less discrepant depending on the method used to determine them. We aim to obtain a new calibration of the Teff parameter for early-type supergiants as a function of observational quantities that are highly sensitive to the ionization balance in the photosphere and its gas pressure, independent of the interstellar extinction, and as much as possible model-independent. The observational quantities that best address our aims are the (lambda1, D) parameters of the BCD spectrophotometric system. They describe the energy distribution around the Balmer discontinuity, which is highly sensitive to Teff and logg. We perform a calibration of the (lambda1, D) parameters into Teff using effective temperatures derived with the bolometric-flux method for 217 program stars, whose individual absolute relative uncertainties are on average 0.05. The final comparison of calculated with obtained Teff values in the (lambda1,D) calibration further show that the latter have total relative uncertainties, which on average are of the order of 0.05 for all spectral types and luminosity classes. The effective temperatures of OB supergiants derived in this work agree on average within some 2000 K with other determinations found in the literature, except those issued from wind-free non-LTE plane-parallel models of stellar atmospheres, which produce effective temperatures that can be overestimated by up to more than 5000 K near Teff = 25000 K.
Fundamental parameters of some B-type stars using NOAO Indo-U.S. Library
本文对NOAO印度-美国图书馆中的83颗B型恒星进行了光谱分析。我们用BCD方法和线覆盖的LTE/NLTE模式大气计算了有效温度、表面重力和自转速度等基本参数。通过将Mg II 4481的X射线谱线与从LTE/NLTE模型计算的理论谱线拟合来估计预计的旋转速度。程序星的演化质量估计使用的演化模型。在大多数情况下，本研究与以前的调查结果相当一致，在某些情况下甚至更准确。
What causes the large extensions of red-supergiant atmospheres? Comparisons of interferometric observations with 1-D hydrostatic, 3-D convection, and 1-D pulsating model atmospheres
上下文B型超巨星是研究各种天体物理学课题的通用工具，从恒星大气层到恒星和星系演化，再到宇宙距离尺度。目标。混合非LTE的方法-线覆盖模型大气计算的假设下，当地的热力学平衡（LTE）结合线形成计算，占LTE的偏差-进行了测试的定量分析的B-型超巨星与质量$M<30 M_{\odot}$，表征一个样本的14个银河系物体。方法.流体静力学平面平行大气结构和合成谱计算与Kurucz的Mesquas 12代码连同非LTE线形成代码细节/表面进行比较，从完整的非LTE计算结果与Tlusty，和湍流压力的影响模型进行了研究。高分辨率光谱分析大气参数，使用斯塔克加宽氢线和多金属电离平衡，并为元素丰度。通过考虑恒星演化轨迹和Gaia EDR 3的弛豫时间，导出了基本的恒星参数.星际红向目标恒星是通过匹配模型的光谱能量分布，以观察到的。结果我们的混合非LTE的方法被证明是相当于流体静力学充分的非LTE模型的更深的光球层的B型超巨星考虑。湍流压力可能与大于10 km s $^{-1}$的微湍流速度相关。通过同时使多个指标一致，所有导出的参数都实现了高精度和准确度。化学物种（He，C，N，O，Ne，Mg，Al，Si，S，Ar，Fe）的丰度是以0.05至0.10 dex的不确定性推导出来的。得到的N/C与N/O的比值与Geneva恒星演化模型的预测一致。
Properties of Galactic B[e] Supergiants: V. 3 Pup -- constraining the orbital parameters and modeling the circumstellar environments
我们报告了对具有B[e]现象的A型超巨星3 Pup = HD 62623的长期光谱监测结果。我们证实了先前的发现，这是一个二元系统。轨道参数是使用4460-4632 A范围内光谱的互相关导出的，其中包含30多条吸收线。发现轨道是圆形的，周期为$137.4\pm0.1$天，径向速度半振幅$K_{1} = 5.0\pm0.8$ km s $^{-1}$，系统径向速度$γ= +26.4\pm2.0$ km s $^{-1}$，质量函数$f(m) = (1.81^{+0.97}_{-0.76})\times10^{-3}$ M $_{\odot}$。该天体可能是从一对初始质量为6.0 M $_{\odot}$和3.6 M $_{\odot}$的天体演变而来，初始轨道周期为5天。根据A超巨星的基本参数（光度$\log$ L/L $_{\odot} = 4.1\pm$ 0. 1，有效温度T $_{\rm eff} = 8500\pm$ 500 K）和质量转移双星的演化轨迹，我们确定了获得者M $_{2} = 8.8\pm$ 0. 5 M $_{\odot}$和施主M $_{1} = 0.75\pm0.25$ M $_{\odot}$的当前质量。我们还模拟了对象的IR过剩，并得出了$\sim 5\,\times10^{-5}$ M $_{\odot}$的光学薄尘埃盘的尘埃质量。轨道参数和H $α…
The IACOB project XIX. Revisiting massive-star evolution with empirical TAMS constraints: updated models, overshoot calibration, and the population of blue supergiants
University of Geneva（日内瓦大学）；European Southern Observatory（欧洲南方天文台）；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）；Universidad de La Laguna（拉古纳大学）
Spectroscopic and physical parameters of Galactic O-type stars. II. Observational constraints on projected rotational and extra broadening velocities as a function of fundamental parameters and stellar evolution
