In this Letter, we have carried out an independent validation of the Gaia Early Data Release 3 (EDR3) photometry using approximately 10,000 Landolt standard stars from Clem & Landolt (2013). Using a machine-learning technique, the UBVRI magnitudes are converted into the Gaia magnitudes and colors and then compared to those in the EDR3, with the effect of metallicity incorporated. Our result confirms the significant improvements in the calibration process of the Gaia EDR3. However, modest trends up to 10 mmag with the G magnitude are found for all magnitudes and colors in the 10 < G < 19 mag range, particularly for the bright and faint ends. With the aid of synthetic magnitudes computed on the CALSPEC spectra with the Gaia EDR3 passbands, absolute corrections are further obtained, paving the way for optimal usage of the Gaia EDR3 photometry in high-accuracy investigations.

在这封信中，我们使用来自 Clem & Landolt (2013) 的大约 10,000 颗 Landolt 标准恒星对 Gaia Early Data Release 3 (EDR3) 光度测量进行了独立验证。使用机器学习技术，UBVRI星等被转换为盖亚星等和颜色，然后与 EDR3 中的星等进行比较，并结合金属丰度的影响。我们的结果证实了 Gaia EDR3 校准过程的显着改进。然而，在 10 < G 的所有星等和颜色中都发现了高达 10 mmag 的适度趋势和G星等< 19 mag 范围，特别是对于亮端和暗端。借助在具有 Gaia EDR3 通带的 CALSPEC 光谱上计算的合成幅度，进一步获得绝对校正，为 Gaia EDR3 光度测量在高精度研究中的最佳使用铺平了道路。