arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.02343astro-ph.SR
收藏

用VLTI/PIONIER测量16颗南星的精确角直径

Precision angular diameters for 16 southern stars with VLTI/PIONIER

Adam D. Rains, Michael J. Ireland, Timothy R. White, Luca Casagrande, I. Karovicova

摘要:

在当前的盖亚时代和大,高信噪比恒星光谱调查,有一个未满足的需要,从根本上校准恒星有效温度的基础上准确的恒星直径的可靠库。在这里,我们提出了一套精确的直径和温度的6个矮星,5个亚巨星,和5个巨星的样本观察与先锋光束组合器在VLTI。科学目标至少在两个序列中进行观测,每个序列有五颗独特的校准星,以进行准确的能见度校准,并减少不良校准器的影响。我们使用标准的PIONIER数据简化管道,但自举干涉图,除了采用蒙特卡罗方法来考虑相关误差采样恒星参数,临边暗化系数,通量,以及预测的校准器角直径。然后将所得的直径与从宽带依巴谷-第谷测光和MARCS模型热辐射修正中得出的热辐射通量以及来自盖亚的视差相结合,以产生所观察到的每颗恒星的有效温度、物理半径和光度。我们的恒星的平均角直径和温度的不确定性分别为0.8%和0.9%,我们的样本包括10颗恒星的直径,没有预先存在的干涉测量。其余的恒星与以前的测量结果是一致的,除了一个单一的恒星,我们在这里观察与先锋在更高的分辨率和更高的灵敏度比在早期的工作中实现。

英文摘要:

In the current era of Gaia and large, high signal to noise stellar spectroscopic surveys, there is an unmet need for a reliable library of fundamentally calibrated stellar effective temperatures based on accurate stellar diameters. Here we present a set of precision diameters and temperatures for a sample of 6 dwarf, 5 sub-giant, and 5 giant stars observed with the PIONIER beam combiner at the VLTI. Science targets were observed in at least two sequences with five unique calibration stars each for accurate visibility calibration and to reduce the impact of bad calibrators. We use the standard PIONIER data reduction pipeline, but bootstrap over interferograms, in addition to employing a Monte-Carlo approach to account for correlated errors by sampling stellar parameters, limb darkening coefficients, and fluxes, as well as predicted calibrator angular diameters. The resulting diameters were then combined with bolometric fluxes derived from broadband Hipparcos-Tycho photometry and MARCS model bolometric corrections, plus parallaxes from Gaia to produce effective temperatures, physical radii, and luminosities for each star observed. Our stars have mean angular diameter and temperatures uncertainties of 0.8% and 0.9% respectively, with our sample including diameters for 10 stars with no pre-existing interferometric measurements. The remaining stars are consistent with previous measurements, with the exception of a single star which we observe here with PIONIER at both higher resolution and greater sensitivity than was achieved in earlier work.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑