.png) Lightcurve-based 3D-model of Hela | |
| Discovery | |
|---|---|
| Discovered by | J. Helffrich |
| Discovery site | Heidelberg |
| Discovery date | 5 June 1910 |
| Designations | |
| (699) Hela | |
| Pronunciation | /ˈhiːlə/[1] |
| 1910 KD | |
| Mars crosser[2] | |
| Orbital characteristics[2] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 113.38 yr (41,411 d) |
| Aphelion | 3.6831 AU (550.98 Gm) |
| Perihelion | 1.5414 AU (230.59 Gm) |
| 2.6123 AU (390.79 Gm) | |
| Eccentricity | 0.40995 |
| 4.22 yr (1,542.1 d) | |
| 3.93957° | |
| 0° 14m 0.384s / day | |
| Inclination | 15.297° |
| 242.548° | |
| 91.479° | |
| Earth MOID | 0.62609 AU (93.662 Gm) |
| Mars MOID | 0.4063 AU (60.78 Gm) |
| Jupiter MOID | 2.10581 AU (315.025 Gm) |
| TJupiter | 3.239 |
| Physical characteristics | |
| Dimensions | 12 - 27 km[3] |
| 3.3962 h (0.14151 d)[2] | |
| 11.72[2] | |
699 Hela is a Mars crossing asteroid. It was discovered on 5 June 1910 at Heidelberg by German astronomer Joseph Helffrich, and may have been named after Hel, the Norse ruler of the underworld.[4] This asteroid is orbiting the Sun at a distance of 2.61 AU with a period of 4.22 years and an eccentricity of 0.41. The orbital plane is inclined at an angle of 15.3° to the plane of the ecliptic.[2]
With an absolute magnitude of 11.7,[2] the asteroid is about 12–27 km in diameter.[3] It is classified as a stony Sk[5] or Sq-type[2] asteroid in the SMASS taxonomy. Photometry data used to produce light curves provide a rotation period of 3.39624±0.00006 h. The lightcurve inversion method was used to build a shape model with a rounded form and an equatorial bulge.[6]
- ^ Noah Webster (1884) A Practical Dictionary of the English Language
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