58534 Logos
A likely contact binary in the cold classical Kuiper belt.
58534 Logos, also known as the binary system Logos–Zoe and provisionally designated 1997 CQ29, is a probable trans-Neptunian contact binary or close-binary triple system belonging to the cold classical population of the Kuiper belt. The primary body, Logos, is about 77 kilometers (48 miles) across, and its companion, Zoe, has an estimated diameter of 66 kilometers (41 miles). The combined mass of the system is (4.58±0.07)×10¹⁷ kg.
In Gnostic tradition, Logos and Zoe are a paired emanation of the deity, forming part of its creation myth. Observations by the Hubble Space Telescope show brightness variations suggesting that Logos itself is likely a close binary or contact binary, rotating once every 17.4 hours.
The system’s orbit, based on a 10-million-year integration, classifies it as a classical Kuiper belt object that never comes closer to the Sun than 38.8 AU (5.80 billion km) nor farther than 52.1 AU.
Logos and Zoe are a binary pair of comparable size, orbiting their common barycenter on a moderately elliptical path. The system was discovered on 4 February 1997, and its binary nature was detected on 17 November 2001 using the Hubble Space Telescope by K. S. Noll, D. C. Stephens, W. M. Grundy, J. Spencer, Robert Millis, Marc Buie, Dale Cruikshank, S. C. Tegler, and W. Romanishin, with the announcement made on 11 February 2002. After the secondary was confirmed, it was officially designated (58534) Logos I and named Zoe. It orbits Logos with a semi-major axis of 8,217 km, completing one orbit in 309.9 days, and has an eccentricity of 0.546. Its estimated mass is (0.15 ± 0.02)×10¹⁸ kg. Zoe may rotate very slowly, and as of 2026, its shape remains unknown.
Quick Facts
- Minorplanet
- yes
- Background
- #C2E0FF
- Discoverer
- Maunakea Obs.
- Discovered
- 4 February 1997
- Mpc Name
- (58534) Logos
- Pronounced
- ˈ · l · oʊ · ɡ · ɒ · s or ˈ · l · ɒ · ɡ · ɒ · s
- Adjectives
- Logian ˈ · l · ɒ · dʒ · i · ə · n
- Named After
- Logos / (Aeon in Ptolemy Gnostics)
- Mp Category
- TNOcubewano / cold
- Epoch
- 13 January 2016 (JD 2457400.5)
- Observation Arc
- 5582 days (15.28 yr)
- Uncertainty
- 3
Facts from the source article.
Lore & Background
In the Gnostic tradition, Logos and Zoe are a paired emanation of the deity, and part of its creation myth. The system was discovered on 4 February 1997, and it was discovered to be a binary object on 17 November 2001 from Hubble Space Telescope observations by K. S. Noll, D. C. Stephens, W. M. Grundy, J. Spencer, Robert Millis, Marc Buie, Dale Cruikshank, S. C. Tegler, and W. Romanishin and announced on 11 February 2002. Once the secondary was confirmed, it was officially designated (58534) Logos I and named Zoe.
Hubble Space Telescope observations of variations in brightness indicate that Logos itself is likely a close binary or contact binary. It rotates with a period of 17.4 hours. Logos is a binary with the components of comparable size orbiting the barycentre on a moderately elliptical orbit. Zoe orbits its primary Logos with a semi-major axis of 8217 km in 309.9 days with an eccentricity of 0.546. Its estimated diameter is 66 km, and mass is (0.15 ± 0.02)×10^18 kg. Zoe potentially has a very slow rotation. As of 2026, its shape is unknown.
Reader's Guide
58534 Logos is significant as a likely trans-Neptunian contact binary or close-binary triple system in the cold classical population of the Kuiper belt. Its discovery as a binary object on 17 November 2001 from Hubble Space Telescope observations, announced on 11 February 2002, added to the understanding of binary systems in the outer Solar System. The system mass is (4.58±0.07)×10^17 kg, with a primary diameter of approximately 77 kilometers and a companion, Zoe, of 66 kilometers. The brightness variations observed by the Hubble Space Telescope suggest that Logos itself may be a close binary or contact binary, making it a candidate for a hierarchical triple system, similar to 47171 Lempo, the first and only confirmed hierarchical triple system in the Kuiper belt. Its orbit, with a 10-million-year integration showing it does not get closer to the Sun than 38.8 AU or further than 52.1 AU, classifies it as a classical Kuiper belt object. The naming follows Gnostic tradition, where Logos and Zoe are a paired emanation of the deity.
Did You Know?
- 58534 Logos was discovered on 4 February 1997.
- Its binary nature was discovered on 17 November 2001 from Hubble Space Telescope observations.
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