15760 Albion
First trans-Neptunian object discovered after Pluto and Charon.
15760 Albion, originally designated 1992 QB1, was the first object found in the region beyond Neptune after Pluto and its moon Charon. Its diameter is estimated between 108 and 167 kilometres. David C. Jewitt and Jane X. Luu discovered it in 1992 at Hawaii's Mauna Kea Observatory. The discoverers nicknamed it "Smiley," and the press briefly hailed it as the tenth planet. It belongs to the "cold" classical population of the Kuiper belt, and its provisional designation gave rise to the term "cubewano" for such objects. The code "QB1" indicates it was the 27th object discovered in the second half of August 1992. By January 2018, roughly 2,400 more objects had been found beyond Neptune, most of them classical Kuiper belt objects. The object was named after Albion, a figure from the mythology of William Blake.
The name Albion comes from the ancient mythological name for Britain. In Blake's complex mythology, Albion is a primeval man whose division creates the Four Zoas. The official naming citation appeared in the Minor Planet Center's Minor Planet Circulars on 31 January 2018. The discoverers had proposed "Smiley," but that name already belonged to asteroid 1613 Smiley, named after astronomer Charles Hugh Smiley. The object carried the number 15760 and remained unnamed until 2018, often referred to simply as "QB1."
In 1993, objects in similar orbits were found, including (15788) 1993 SB, (15789) 1993 SC, (181708) 1993 FW, and (385185) 1993 RO. Within twenty years of Albion's discovery, over a thousand bodies had been found in the Kuiper belt, orbiting between about 30 and 50 AU from the Sun, revealing a vast belt beyond just Pluto and Albion. By 2018, more than 2,000 Kuiper belt objects had been discovered.
Based on a generic magnitude-to-diameter conversion, assuming an albedo of 0.9 and a magnitude of 7.0, Albion measures about 167 kilometres across. Astronomer Mike Brown estimates a mean diameter of 108 kilometres, deeming it too small to be a dwarf planet candidate ("probably not"). As of 2021, no rotational lightcurve has been obtained; its rotation period, pole, composition, and shape remain unknown.
Quick Facts
- Minorplanet
- yes
- Background
- #C2E0FF
- Discoverer
- D. C. Jewitt / J. X. Luu
- Discovery Site
- Mauna Kea Obs.
- Discovered
- 30 August 1992
- Mpc Name
- (15760) Albion
- Pronounced
- ˈ · æ · l · b · i · ə · n
- Named After
- Albion (mythology by William Blake)
- Mp Category
- TNOcubewano (cold) / distant
- Epoch
- 31 May 2020 (JD 2459000.5)
- Uncertainty
- 3
- Observation Arc
- 26.34 yr (9,621 days)
Facts from the source article.
Lore & Background
15760 Albion was discovered in 1992 by David C. Jewitt and Jane X. Luu at the Mauna Kea Observatory in Hawaii. After the discovery, they dubbed the object 'Smiley' and it was shortly hailed as the tenth planet by the press. The name 'Smiley' was already used for asteroid 1613 Smiley, so the object remained unnamed until January 2018, when it was named after Albion from William Blake's mythology. Its provisional designation '1992 QB1' decodes to indicate it was the 27th object found in the second half of August of that year. As of January 2018, around 2,400 further objects have been found beyond Neptune, a majority of which are classical Kuiper belt objects.
Reader's Guide
15760 Albion is significant as the first trans-Neptunian object discovered after Pluto and Charon, marking the beginning of the exploration of the Kuiper belt. Its discovery by Jewitt and Luu in 1992 revealed a vast belt of bodies beyond Neptune, more than just Pluto and Albion themselves. The object gave rise to the term 'cubewano' for classical Kuiper belt objects, derived from the QB1 portion of its provisional designation. In the twenty years after its discovery, over one thousand bodies were found in the Kuiper belt orbiting between about 30 and 50 AU from the Sun. By 2018, over 2000 Kuiper belt objects had been discovered. The object's naming history reflects the challenges of asteroid nomenclature: the discoverers' suggested name 'Smiley' was already taken, and it remained unnamed until January 2018 when it was named after Albion from William Blake's mythology. Its physical characteristics remain poorly known, with no rotational lightcurve obtained as of 2021, and its composition and shape unknown.
Discovery and the Tenth Planet Frenzy
In the summer of 1992, astronomers David C. Jewitt and Jane X. Luu, working from the Mauna Kea Observatory in Hawaii, made a finding that would reshape our understanding of the outer solar system. Their new object, provisionally catalogued as 1992 QB1, became the first trans-Neptunian body identified after the well-known pair of Pluto and its moon Charon. The designation itself encodes a small piece of history: the "Q" places it in the second half of August, and the "B1" indicates it was the twenty-seventh object recorded during that fortnight. Jewitt and Luu playfully christened their find "Smiley," and the story quickly escaped the observatory. Newspapers and broadcasters seized on the discovery, declaring a tenth planet had been found. The excitement was understandable—here was a new world beyond Neptune—but the object would ultimately be classified as a minor planet rather than a full-fledged planet. Still, that brief moment of public wonder marked the opening chapter of the Kuiper belt era.
A Name from Blake's Mythology
For over twenty-five years, the object was known simply by its provisional tag, "QB1," a shorthand that was technically ambiguous without the discovery year attached. The discoverers' preferred name, "Smiley," could not be used because it was already assigned to asteroid 1613 Smiley, which honors American astronomer Charles Hugh Smiley. It was not until January 31, 2018, that the Minor Planet Center published the official naming citation (M.P.C. 108697), bestowing the name Albion. The choice draws from the elaborate mythological system of English poet and painter William Blake (1757–1827). In Blake's cosmology, Albion is the primeval, island-dwelling figure whose fragmentation gives rise to the Four Zoas—Urizen, Tharmas, Luvah (or Orc), and Urthona (or Los). The word Albion itself traces back to an ancient, mythological name for Britain. Thus the distant ice world carries a name rooted in a poet's vision of primordial creation and division.
Sowing the Seeds of the Kuiper Belt
Albion's discovery did not merely add one more body to a catalog; it opened a door. In the very next year, 1993, astronomers identified several more objects in comparable orbits, including 15788 (1993 SB), 15789 (1993 SC), 181708 (1993 FW), and 385185 (1993 RO). Over the following two decades, more than a thousand additional bodies were tracked in the region between roughly 30 and 50 astronomical units from the Sun, confirming that the outer solar system was far richer than Pluto and a single companion. By 2018, the tally of known Kuiper belt objects had surpassed two thousand, and by January of that year approximately 2,400 further trans-Neptunian bodies had been catalogued, the great majority belonging to the classical population. Albion's provisional designation also left a lasting linguistic mark: the "QB1" in its name inspired the term "cubewano," now the standard label for cold classical Kuiper belt objects like itself.
A Small, Still Mysterious World
Despite its historical importance, Albion remains a modest and poorly characterized body. Using a standard magnitude-to-diameter conversion with an assumed albedo of 0.9 and an observed magnitude of 7.0, its diameter works out to roughly 167 kilometres (about 104 miles). However, astronomer Mike Brown, applying different assumptions, estimates a mean diameter closer to 108 kilometres (67 miles). At that smaller figure, Brown has judged the object "probably not" large enough to qualify as a dwarf planet candidate. As of 2021, no rotational lightcurve has been successfully extracted from photometric observations, meaning its spin period, axial orientation, surface composition, and overall shape all remain unknown. It is classified as a "cold" classical Kuiper belt object—a population defined by its relatively undisturbed orbit—yet even its most basic physical properties elude measurement. For a body that launched an entire field of study, Albion keeps a great deal of its character hidden in the dark.
Frequently Asked Questions
What is 15760 Albion?
15760 Albion (provisional name 1992 QB1) is a small, icy trans-Neptunian object orbiting in the cold classical region of the Kuiper belt. It holds the distinction of being the first body ever identified beyond Neptune after the Pluto–Charon system, marking the opening of an entirely new chapter in solar-system exploration.
Who found 15760 Albion and where?
Astronomers David C. Jewitt and Jane X. Luu spotted it in 1992 using the telescopes at Mauna Kea Observatory in Hawaii. The pair affectionately nicknamed it "Smiley" during their discovery observations, a label that stuck in early press coverage.
How large is 15760 Albion?
Its diameter is estimated to fall somewhere between roughly 108 and 167 kilometres, with Mike Brown's analysis settling near the lower bound at about 108 km. That places it in the small-moon or large-asteroid size range—far smaller than Pluto but still a solid rocky-ice world.
Why does 15760 Albion matter to the TNO community?
It proved that an entire hidden population of objects was lurking past Neptune, launching decades of Kuiper belt research and observation. Its provisional code "QB1" also became the root of the word "cubewano," the name fans and researchers use for members of the cold classical belt.
What does "cubewano" mean and why is Albion the namesake?
"Cubewano" is a playful contraction of "cubed B-one," drawn directly from Albion's 1992 QB1 provisional designation. The term labels the low-inclination, non-resonant classical Kuiper belt family to which Albion belongs, and it has stuck in both the scientific literature and the fan community ever since.
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