154 Bertha

It is probably named after Berthe Martin-Flammarion, sister of the astronomer Camille Flammarion.

[8] 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.

[9] 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.

[6] This is classified as a C-type asteroid[7] and it has an estimated diameter of about 187 km.