66652 Borasisi
Binary classical Kuiper belt object with a very red surface.
66652 Borasisi, designated as a binary system (66652) Borasisi–Pabu, is a classical Kuiper belt object. It was first observed in September 1999 by Chad Trujillo, Jane X. Luu, and David C. Jewitt. Its binary nature was confirmed on 23 August 2003 by K. Noll and colleagues using the Hubble Space Telescope.
The system consists of two components of roughly equal size, each estimated to be between 100 and 130 kilometers across. They orbit their common center of mass in a moderately elliptical path. The total mass of the system is approximately 3.4 × 10¹⁸ kg. The secondary component, named Pabu, completes an orbit around the primary every 46.2888 ± 0.0018 days, at a semi-major axis of 4528 ± 12 km and an orbital eccentricity of 0.4700 ± 0.0018. The orbit is tilted about 54° relative to the line of sight, meaning it is roughly 35° from a pole-on orientation.
Both bodies in the Borasisi–Pabu system have very red surfaces.
The name Borasisi comes from a fictional creation deity in Kurt Vonnegut's novel *Cat's Cradle*. In the story, Borasisi is the Sun and Pabu is the Moon. The narrative describes Borasisi holding Pabu, hoping for a fiery child, but Pabu gives birth to cold planets, which Borasisi discards. Pabu is later cast away and goes to live with Earth, her favorite child because it has people who love her.
Around 2005, Borasisi was considered as a possible target for the proposed New Horizons 2 mission, which would have included a flyby of Triton and Neptune.
Quick Facts
- Minorplanet
- yes
- Background
- #C2E0FF
- Pronounced
- b · ɒr · ə · ˈ · s · iː · s · i
- Discoverer
- C. Trujillo, J. Luu and D. Jewitt
- Discovered
- 8 September 1999
- Mpc Name
- (66652) Borasisi
- Mp Category
- trans-Neptunian object / cubewano / SCATNEAR(?)
- Observation Arc
- 4790 days (13.11 yr)
- Uncertainty
- 3
- Epoch
- 13 January 2016 (JD 2457400.5)
- Semimajor
- 43.555 AU
- Perihelion
- 39.819 AU
Facts from the source article.
Lore & Background
In 2003 it was discovered that Borasisi is a binary with components of comparable size (about 100–130 km) orbiting the barycentre on a moderately elliptical orbit. The total system mass is about 3.4 × 10^18 kg. The companion, named Pabu, orbits its primary in 46.2888 ± 0.0018 days on an orbit with a semi-major axis of 4528 ± 12 km and an eccentricity 0.4700 ± 0.0018. The orbit is inclined with respect to the observer by about 54°, meaning it is about 35° from the pole-on position.
The surface of both components of the Borasisi–Pabu system is very red. Borasisi is named after a fictional creation deity from the novel Cat's Cradle by Kurt Vonnegut; in the book, Borasisi is the Sun and Pabu is the Moon. Around 2005, Borasisi was considered as a target for the proposed New Horizons 2 after a Triton/Neptune flyby.
Reader's Guide
The Borasisi–Pabu system is notable as a binary classical Kuiper belt object discovered in 1999 and identified as a binary in 2003 using the Hubble Space Telescope. Its components are of comparable size, each roughly 100–130 km, and orbit a common barycentre with a moderately elliptical orbit. The system's total mass is approximately 3.4 × 10^18 kg, and the companion Pabu has a well-determined orbital period of about 46.3 days, a semi-major axis of about 4528 km, and an eccentricity of 0.47. The orbit is inclined roughly 54° to the observer, placing it about 35° from pole-on. Both components exhibit a very red surface, a characteristic noted in the article. The naming derives from Kurt Vonnegut's Cat's Cradle, where Borasisi is the sun and Pabu the moon, adding a literary dimension. Around 2005, the object was considered as a target for the proposed New Horizons 2 mission following a Triton/Neptune flyby, indicating its potential scientific interest for exploration. The article provides precise orbital and physical parameters, making it a well-characterized binary in the Kuiper belt.
Did You Know?
- The companion Pabu orbits Borasisi with an eccentricity of 0.4700 ± 0.0018.
- The surface of both components is very red.
Frequently Asked Questions
What is 66652 Borasisi?
Borasisi is a classical Kuiper belt object located beyond Neptune's orbit. It is notable for being a binary system, meaning it consists of two roughly equal-sized bodies that orbit a shared center of mass in a moderately elliptical path.
Who discovered 66652 Borasisi and when?
The object was first spotted in September 1999 by the team of Chad Trujillo, Jane X. Luu, and David C. Jewitt. Its binary nature was later confirmed on 23 August 2003 by K. Noll and colleagues using the Hubble Space Telescope.
How large are the two components of the Borasisi system?
Each of the two bodies is estimated to measure somewhere between 100 and 130 kilometers across, making them remarkably similar in size to one another. The combined mass of the entire system works out to roughly 3.4 × 10¹⁸ kilograms.
What is Pabu and how is it connected to Borasisi?
Pabu is the name given to the secondary component of the 66652 Borasisi binary pair. Together the two bodies form a gravitationally bound system that circles their mutual barycenter in a moderately elliptical orbit.
What is distinctive about Borasisi's surface?
The system stands out among classical Kuiper belt objects because of its very red surface coloration. This deep reddish hue suggests the presence of complex organic compounds or irradiation products on the outer ice layers.
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