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.[2] An international team of astronomers observed this minor planet photometrically in 2012, determining a rotation period of 23.93±0.01 h with an amplitude of 0.15±0.03 in magnitude.[3]
Discovery | |
---|---|
Discovered by | Max Wolf |
Discovery site | Heidelberg Observatory |
Discovery date | 20 March 1915 |
Designations | |
(801) Helwerthia | |
1915 WQ; A924 OD; 1925 RG; 1970 GS1 | |
Orbital characteristics[1] | |
Epoch 31 July 2016 (JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 101.08 yr (36918 d) |
Aphelion | 2.8087 AU (420.18 Gm) |
Perihelion | 2.4007 AU (359.14 Gm) |
2.6047 AU (389.66 Gm) | |
Eccentricity | 0.078337 |
4.20 yr (1535.4 d) | |
47.6362° | |
0° 14m 4.056s / day | |
Inclination | 14.130° |
185.973° | |
335.076° | |
Earth MOID | 1.41172 AU (211.190 Gm) |
Jupiter MOID | 2.17333 AU (325.126 Gm) |
TJupiter | 3.366 |
Physical characteristics | |
16.615±1.25 km | |
23.93 h (0.997 d) | |
0.0384±0.007 | |
11.55 | |
References
edit- ^ "801 Helwerthia (1915 WQ)". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 6 May 2016.
- ^ "Supplemental IRAS Minor Planet Survey". Archived from the original on 23 June 2006.
- ^ Pilcher, Frederick; et al. (October 2012), "Rotation Period Determination for 801 Helwerthia", The Minor Planet Bulletin, 39 (4): 222–225, Bibcode:2012MPBu...39..222P
External links
edit- 801 Helwerthia at AstDyS-2, Asteroids—Dynamic Site
- 801 Helwerthia at the JPL Small-Body Database