About Periboea
Periboea is an uncommon asteroid. It swings within 5.039 AU of the Sun at perihelion.
Locked in a gravitational sweet spot 60° ahead of or behind a much larger body, shepherded there for billions of years.
Uncommon asteroid 31 EP
Periboea
Position computed live · sbdb
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Live ephemeris
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Score breakdown
· 5 badgesUncommon 34 pts → Rare
- Trojan +10
- Notably bright (low H) +8
- Has a proper name +8
- Steeply tilted orbit (i > 40°) +4
- Asteroid +1
Total score 31
3 more points to reach Rare.
Badges
- Asteroid · +1
- Trojan · +10
- Notably bright (low H) · +8
- Has a proper name · +8
- Steeply tilted orbit (i > 40°) · +4
Trivia
What makes it special
- Trojan. Locked in a gravitational sweet spot 60° ahead of or behind a much larger body, shepherded there for billions of years.
What it actually is
- Its orbit family. A Jupiter trojan, parked in a gravitational sweet spot 60° ahead of or behind Jupiter and shepherded there for billions of years. There may be as many trojans as there are main-belt asteroids.
- Closest approach. At its nearest it comes within 5.04 AU of the Sun — inside the orbit of Jupiter.
- One lap. A single orbit around the Sun takes it about 12 years.
- How far it roams. Its orbit swings between 5.04 and 5.47 AU from the Sun.
Sense of scale
- Sense of scale. In everyday terms it is roughly 6.1× the height of Mount Everest.
- Walk around it. Walking its equator at a steady pace, eight hours a day, would take about 4.2 days.
By the numbers
- Size. Roughly 54.1 km across.
Properties
- albedo
- 0.066
- aphelion au
- 5.47
- designation
- 12929
- diameter km
- 54.077
- eccentricity
- 0.0409
- full name
- 12929 Periboea (1999 TZ1)
- h mag
- 10.07
- inclination
- 43.41
- mean motion deg day
- 0.0818
- moid au
- 4.09
- name
- Periboea
- named
- yes
- orbit class
- TJN
- perihelion au
- 5.039
- rotation period h
- 9.272
- semi major au
- 5.255
- trojan
- yes
How to see it
Like any astronomical target, Periboea 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 Periboea is an uncommon asteroid
Periboea scores 31 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 3 points would lift it into a rarer tier.
That score comes from 5 science badges — Asteroid, Trojan, Notably bright (low H), Has a proper name and Steeply tilted orbit (i > 40°) — 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.