Gaia Early Data Release 3 (EDR3) provides trigonometric parallaxes for 1.5 billion stars, with reduced systematics compared to Gaia Data Release 2 and reported precisions better by up to a factor of 2. New to EDR3 is a tentative model for correcting the parallaxes of magnitude-, position-, and color-dependent systematics for five- and six-parameter astrometric solutions, Z ₅ and Z ₆. Using a sample of over 2000 first-ascent red giant branch stars with asteroseismic parallaxes, I perform an independent check of the Z ₅ model in a Gaia magnitude range of 9 ≲ G ≲ 13 and color range of 1.4 μm⁻¹ ≲ ν _eff ≲ 1.5 μm⁻¹. This analysis therefore bridges the Gaia team’s consistency check of Z ₅ for G > 13 and indications from independent analysis using Cepheids of a ≈15 μas overcorrection for G < 11. I find overcorrection sets in at G ≲ 10.8, such that Z ₅-corrected EDR3 parallaxes are larger than asteroseismic parallaxes by 15 3 μas. For G ≳ 10.8, EDR3 and asteroseismic parallaxes in the Kepler field agree up to a constant consistent with expected spatial variations in EDR3 parallaxes after a linear, color-dependent adjustment. I also infer an average underestimation of EDR3 parallax uncertainties in the sample of 22% 6%, consistent with the Gaia team’s estimates at similar magnitudes and independent analysis using wide binaries. Finally, I extend the Gaia team’s parallax spatial covariance model to brighter magnitudes (G < 13) and smaller scales (down to ≈0.1), where systematic EDR3 parallax uncertainties are at least ≈3–4 μas.

Gaia Early Data Release 3 (EDR3) 提供了 15 亿颗恒星的三角视差，与 Gaia Data Release 2 相比系统性降低，报告的精度提高了 2 倍。 EDR3 的新功能是用于校正星等视差的暂定模型-、位置和颜色相关的五参数和六参数天体测量解决方案的系统学，Z ₅和Z ₆。使用超过 2000 颗具有星震视差的首次上升红巨星分支恒星的样本，我在盖亚星等范围 9 ≲ G ≲ 13 和颜色范围 1.4 μ m ⁻¹ ≲ ν _eff中对Z ₅模型进行了独立检查≲ 1.5 μ m ^-1。因此，该分析将 Gaia 团队对G > 13的Z ₅一致性检查和使用 ≈15 μ 的造父变星作为G < 11 的过度校正的独立分析的指示联系起来。我发现过度校正设置在G ≲ 10.8 处，使得Z ₅ -校正后的 EDR3 视差比星震视差大 15 3 μ as。对于G ≳ 10.8，开普勒场中的 EDR3 和星震视差在线性、颜色相关的调整后与 EDR3 视差的预期空间变化一致。我还推断出样本中 EDR3 视差不确定性的平均低估率为 22% 6%，这与 Gaia 团队在类似幅度下的估计和使用宽二进制的独立分析一致。最后，我将 Gaia 团队的视差空间协方差模型扩展到更亮的星等 ( G < 13) 和更小的尺度（低至 ≈0.1），其中系统 EDR3 视差不确定性至少为 ≈3–4 μ as。