论文标题
盖亚（Gaia）的红色超级对流的未检测
A Non-Detection of Red Supergiant Convection in Gaia
论文作者
论文摘要
红色超级巨人（RSG）上的大规模表面对流会导致恒星的光中心移动，这可以通过Gaia测量，并用作这些稀有但重要恒星的表面动力学的新探针。与亮度变化不同，光中心运动将提供有关对流细胞物理尺度的信息。信号是RSG在恒星半径的几％的水平上显示出多余的天文噪声。不幸的是，我们发现Gaia EDR3的过度天文噪声水平大约是一个数量级，而无法检测到预测的运动，并且RSG与其他相似幅度和视差的恒星无法区分的星体噪声过多。典型的多余的星体噪声会随着G幅度稳步降低（对于G <11 mag），因此比较具有相似亮度的恒星至关重要。
Large scale surface convection on red supergiants (RSGs) can lead to shifts in the photocenter of the star which might be measured by Gaia and used as a new probe of the surface dynamics of these rare but important stars. Unlike brightness variations, photocenter motions would provide information on the physical scale of the convective cells. The signal would be that RSGs show an excess astrometric noise at the level of a few percent of the stellar radius. Unfortunately, we find that the excess astrometric noise level of Gaia EDR3 is roughly an order of magnitude too large to detect the predicted motions and that RSGs have excess astrometric noise indistinguishable from other stars of similar magnitude and parallax. The typical excess astrometric noise steadily decreases with G magnitude (for G<11 mag), so it is crucial to compare stars of similar brightness.
