| Minorplanet: | yes |
| Background: |
|
| 801 Helwerthia | |
| Mpc Name: | (801) Helwerthia |
| Alt Names: | 1915 WQ; A924 OD; 1925 RG; 1970 GS1 |
| Discovered: | 20 March 1915 |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Eccentricity: | 0.078337 |
| Semimajor: | 2.6047AU |
| Perihelion: | 2.4007AU |
| Aphelion: | 2.8087abbr=onNaNabbr=on |
| Period: | 4.20 yr (1535.4 d) |
| Inclination: | 14.130° |
| Asc Node: | 185.973° |
| Arg Peri: | 335.076° |
| Mean Motion: | / day |
| Orbit Ref: | [1] |
| Observation Arc: | 101.08 yr (36918 d) |
| Uncertainty: | 0 |
| Abs Magnitude: | 11.55 |
| Rotation: | 23.93abbr=onNaNabbr=on |
| Moid: | 1.41172AU |
| Jupiter Moid: | 2.17333AU |
| Tisserand: | 3.366 |
801 Helwerthia is a C-type asteroid orbiting in the Main belt near the Eunomia family. However, it is not a family member but an un-related interloper in the region because its composition is inconsistent with membership. Its diameter is about 33 km, its albedo around 0.038. An international team of astronomers observed this minor planet photometrically in 2012, determining a rotation period of with an amplitude of in magnitude.