949 Hel

949 Hel
Discovery [1]
Discovered byM. F. Wolf
Discovery siteHeidelberg Obs.
Discovery date11 March 1921
Designations
(949) Hel
Pronunciation/ˈhɛl/[2]
Named after
Hel (Norse mythology)[3]
A921 EM · 1952 DN
1954 SN1 · 1921 JK
main-belt [1][4] · (outer)
background [5][6]
Orbital characteristics [4]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc91.34 yr (33,361 d)
Aphelion3.5804 AU
Perihelion2.4255 AU
3.0029 AU
Eccentricity0.1923
5.20 yr (1,901 d)
358.26°
0° 11m 21.84s / day
Inclination10.701°
321.17°
249.54°
Physical characteristics
  • 60.98±0.74 km[7]
  • 63.494±0.743 km[8]
  • 63.56±4.01 km[9]
  • 69.17±1.4 km[10]
Mass(1.73±0.62)×1018 kg[9]
Mean density
12.86±5.19 g/cm3[9]
8.215±0.001 h[11][12]
9.8[1][4]

949 Hel (prov. designation: A921 EM or 1921 JK) is a dark background asteroid from the outer regions of the asteroid belt, approximately 63 kilometers (39 miles) in diameter. It was discovered by German astronomer Max Wolf at the Heidelberg Observatory on 11 March 1921.[1] The transitional X-type asteroid has a rotation period of 8.2 hours. It was named in memory of the discoverer, after the Norse goddess of the dead, Hel.[3]

  1. ^ a b c d Cite error: The named reference MPC-object was invoked but never defined (see the help page).
  2. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  3. ^ a b Cite error: The named reference springer was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference jpldata was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference AstDys-object was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Ferret was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference AKARI was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Masiero-2014 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Carry-2012 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference SIMPS was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference lcdb was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Brines-2017 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference Lazzaro-2004 was invoked but never defined (see the help page).