It reached a peak brightness of magnitude 6.0, making it visible to the naked eye under ideal observing conditions.

It was discovered on June 12, 2021, by Seiji Ueda of Kushiro Japan, just hours before it obtained peak brightness.

[6] Subsequent analysis of ASAS-SN data showed the star had a magnitude of 16.62 (g band) 8.4 hours before it was discovered.

Photometric observations taken during June, July and August 2021 found that binary pair's orbital period is 3.670416 ± 0.0008 hours.

[3] The Zwicky Transient Facility had been observing the region of the sky containing Nova Herculis 2021 since March 2018, and analysis of that data yielded a spin period of 8.357 minutes for the white dwarf.