Astronomical objects discovered in 1877

Phobos (systematic designation:) is the innermost and larger of the two natural satellites of Mars, the other being Deimos. The two moons were discovered in 1877 by American astronomer Asaph Hall. Phobos is named after the Greek god of fear and panic, who is the son of Ares (Mars) and twin brother of Deimos.

NGC 2445 is a peculiar ring galaxy in the constellation Lynx. The galaxy lies about 200 million light years away from Earth, which means, given its apparent dimensions, that NGC 2445 is approximately 100,000 light years across. It was discovered by Édouard Stephan on January 18, 1877. The galaxy interacts with another galaxy, NGC 2444, and as a result its shape is distorted and new stars are formed.

178 Belisana is a stony background asteroid from the inner regions of the asteroid belt, approximately 38 kilometers (24 miles) in diameter. It was discovered on 6 November 1877, by Austrian astronomer Johann Palisa at the Austrian Naval Observatory in today's Croatia. The S-type asteroid has a rotation period of 12.32 hours and a rather spherical shape. It was named after the Celtic goddess Belisama (Belisana).

176 Iduna is a large main-belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on October 14, 1877, in Clinton, New York. It is named after Sällskapet Idun, a club in Stockholm that hosted an astronomical conference; Idun (Iðunn, Iduna) is also a Norse goddess. A G-type asteroid, it has a composition similar to that of the largest main-belt asteroid, 1 Ceres.

NGC 2535 is an unbarred spiral galaxy in the constellation Cancer. It was discovered on 22 January 1877 by French astronomer Édouard Stephan.

Deimos (systematic designation: Mars II) is the smaller and outer of the two natural satellites of Mars, the other being Phobos. Deimos has a mean radius of 6.2 km (3.9 mi) and takes 30.3 hours to orbit Mars. Deimos is 23,460 km (14,580 mi) from Mars, much farther than Mars's other moon, Phobos. It is named after Deimos, the Ancient Greek god and personification of dread and terror.

NGC 2528 is an intermediate spiral galaxy in the constellation of Lynx. Its velocity with respect to the cosmic microwave background is 4098 ± 12 km/s, which corresponds to a Hubble distance of 60.45 ± 4.23 Mpc (~197 million light-years). It was discovered by French astronomer Édouard Stephan on 22 January 1877.

179 Klytaemnestra is a stony Telramund asteroid from the outer regions of the asteroid belt, approximately 77 kilometers (48 miles) in diameter. It was discovered on 11 November 1877, by Canadian-American astronomer James Craig Watson at the old Ann Arbor Observatory in Michigan, United States. It was his last discovery three years before his death. The transitional S-type asteroid has a rotation period of 11.17 hours. It was named after Clytemnestra from Greek mythology.

177 Irma is a fairly large and dark main belt asteroid. It was discovered by the French brothers Paul Henry and Prosper Henry on November 5, 1877. Paul was credited for this discovery. The meaning of the name Irma is unknown.

175 Andromache is a main-belt asteroid that was discovered by Canadian-American astronomer J. C. Watson on October 1, 1877, and named after Andromache, wife of Hector during the Trojan War. Watson's telegram to Europe announcing the discovery became lost, and so notification did not arrive until several weeks later. As a result, another minor planet, later designated 176 Iduna, was initially assigned the number 175.