Discovered by P. M. Henry Minor planet category Main belt Discovered 4 November 1875 Orbits Sun Discovery site Paris Observatory | Discovery date 4 November 1875 Observation arc 130.75 yr (47758 d) Inclination 20.9724° Discoverer Prosper Henry Asteroid group Asteroid belt | |
Aphelion 3.44394 AU (515.206 Gm) Perihelion 2.94994 AU (441.305 Gm) Similar 153 Hilda, 165 Loreley, 127 Johanna | ||
154 Bertha is a main-belt asteroid. It was discovered by the French brothers Paul Henry and Prosper Henry on November 4, 1875, but the credit for the discovery was given to Prosper. It is probably named after Berthe Martin-Flammarion, sister of the astronomer Camille Flammarion.
Observations performed at the Palmer Divide Observatory in Colorado Springs, Colorado in during 2007 produced a light curve with a period of 22.30 ± 0.03 hours and a brightness range of 0.10 ± 0.02 in magnitude. A 1998 measurement gave a value of 27.6 hours, which doesn't fit the PDO data. In 2011, observations from the Organ Mesa Observatory in Las Cruces, New Mexico were used to determine a rotation period of 25.224 ± 0.002 hours with a brightness variability of 0.10 ± 0.01 magnitude, ruling out previous studies.
This is classified as a C-type asteroid and it has an estimated diameter of about 187 km.