The black hole in the quasar SDSS J140821.67+025733.2 has been reported to have a mass of 1.96 10¹¹ M _⊙ based on measurements from the SDSS DR12 Quasar Catalog. As a result, references to this object as the most massive known black hole in the universe have recently appeared in scientific articles and in popular media including Wikipedia. We show that this extremely high mass estimate is incorrect, resulting from a faulty measurement of the C iv line width. From a new measurement of the Mg ii line width, we derive an estimate of M _BH ≈ 8 10⁹ M _⊙.

中文翻译：

---

Quasar SDSS J140821.67+025733.2 不包含 1960 亿太阳质量的黑洞

根据SDSS DR12 Quasar Catalog 的测量结果，据报道类星体 SDSS J140821.67+ _025733.2中的黑洞质量为 1.96 10 ¹¹ M⊙ 。 因此，最近出现在科学文章和包括维基百科在内的流行媒体中，将这个物体称为宇宙中已知最大的黑洞。我们表明，这种极高的质量估计是不正确的，这是由于对 C  iv线宽的错误测量造成的。根据对 Mg ii线宽的新测量 ，我们推导出M _BH  ≈ 8 10 ⁹ M⊙的估计_值。