M42, the Orion nebula, was discovered by Nicolas-Claude Fabri de Peiresc on November 26, 1610 and first observed by William Herschel on March 4, 1774.

M43 (Herschel designation III.1) was discovered by Jean-Jacques d'Ortous de Mairan some time before 1731 and first observed by William Herschel on September 20, 1783.

M78 was discovered by Pierre Méchain in March 1780 and first observed by William Herschel on September 20, 1783.

NGC 2024 (Herschel designation V.28) was discovered by William Herschel on January 1, 1786.

NGC 2170 and NGC 2185 (Herschel designation IV.19 and 20) were discovered by William Herschel on October 16, 1784.
NGC 2182 (Herschel designation IV.38) was discovered by William Herschel on February 24, 1786.

NGC 2215 (Herschel designation VII.20) was discovered by William Herschel on November 1, 1785.