About Hermione
Hermione is a rare asteroid. It has spectral type Ch and swings within 3.027 AU of the Sun at perihelion.
An outer main-belt asteroid, out towards Jupiter where the rocks grow darker and richer in carbon and ice.
Rare asteroid 46 EP
Hermione
Position computed live · asteroid
Loading sky survey…
Live ephemeris
This object moves — fetching its current position…
Score breakdown
· 7 badgesRare 50 pts → Epic
- Large body (100-500 km) +12
- Darker than charcoal +10
- Notably bright (low H) +8
- Has a proper name +8
- Carbonaceous — as old as the solar system +6
- Asteroid +1
- Main-belt asteroid +1
Total score 46
4 more points to reach Epic.
Badges
- Asteroid · +1
- Large body (100-500 km) · +12
- Notably bright (low H) · +8
- Has a proper name · +8
- Main-belt asteroid · +1
- Darker than charcoal · +10
- Carbonaceous — as old as the solar system · +6
Trivia
What it actually is
- Its orbit family. An outer main-belt asteroid, out towards Jupiter where the rocks grow darker and richer in carbon and ice.
- Closest approach. At its nearest it comes within 3.03 AU of the Sun — inside the orbit of Jupiter.
- One lap. A single orbit around the Sun takes it about 6.4 years.
- How far it roams. Its orbit swings between 3.03 and 3.89 AU from the Sun.
Sense of scale
- Sense of scale. In everyday terms it is about 9.7× the length of Manhattan island.
- Walk around it. Walking its equator at a steady pace, eight hours a day, would take about 16.4 days.
By the numbers
- Size. Roughly 209 km across.
What's in a name
- Named. Notable enough to have earned a proper name, not just a catalogue number.
Properties
- albedo
- 0.0482
- aphelion au
- 3.89
- designation
- 121
- diameter km
- 209
- eccentricity
- 0.1244
- full name
- 121 Hermione (A872 JA)
- h mag
- 7.39
- inclination
- 7.57
- mean motion deg day
- 0.1533
- moid au
- 2.04
- name
- Hermione
- named
- yes
- orbit class
- OMB
- perihelion au
- 3.027
- rotation period h
- 5.5513
- semi major au
- 3.458
- spec taxonomy
- Ch
- spect
- Ch
How to see it
Like any astronomical target, Hermione is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. Because it moves against the background stars, the live position panel on this page tracks where it is right now. The visibility panel above works out tonight's viewing window for your saved location.
Why Hermione is a rare asteroid
Hermione scores 46 points on Spacedle's rarity scale, which places it in the rare tier. Another 4 points would lift it into a rarer tier.
That score comes from 7 science badges — Asteroid, Large body (100-500 km), Notably bright (low H), Has a proper name, Main-belt asteroid, Darker than charcoal and Carbonaceous — as old as the solar system — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.