| Minorplanet: | yes |
| Background: |
|
| 154 Bertha | |
| Discovery Ref: | [1] |
| Discovered: | 4 November 1875 |
| Mpc Name: | (154) Bertha |
| Alt Names: | A875 VD |
| Orbit Ref: | [2] |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Semimajor: | 3.19694AU |
| Perihelion: | 2.94994AU |
| Aphelion: | 3.44394AU |
| Eccentricity: | 0.077261 |
| Period: | 2087.92NaN2 |
| Arg Peri: | 159.722° |
| Inclination: | 20.9724° |
| Asc Node: | 36.7441° |
| Mean Anomaly: | 125.046° |
| Avg Speed: | 16.63 km/s |
| Dimensions: | |
| Surface Grav: | 0.0517 m/s² |
| Escape Velocity: | 0.0978 km/s |
| Rotation: | 25.224abbr=onNaNabbr=on |
| Abs Magnitude: | 7.58, 7.530 |
| Albedo: | 0.0483 ± 0.0107 |
| Mean Motion: | / day |
| Observation Arc: | 130.75 yr (47758 d) |
| Uncertainty: | 0 |
| Moid: | 1.95152AU |
| Jupiter Moid: | 1.53096AU |
| Tisserand: | 3.087 |
154 Bertha is a main-belt asteroid. It was discovered by the French brothers Paul Henry and Prosper Henry on 4 November 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.