66652 Borasisi

66652 Borasisi
Discovery
Discovered by A. Trujillo, J. Luu and D. Jewitt
Discovery date September 8, 1999
Designations
MPC designation (66652) 1999 RZ253
trans-Neptunian object
cubewano[1][2]
SCATNEAR[3]
Orbital characteristics[4]
Epoch June 18, 2009 (JD 2455000.5)
Aphelion 48.164 AU
Perihelion 39.982 AU
44.073 AU
Eccentricity 0.0928
292.60 a (106,871 d)
46.593°
Inclination 0.5629°
84.74°
200.0°
Known satellites Pabu
(137 km in diameter?)[5]
Physical characteristics
Dimensions 124–196 km[6]
Mass 3.433 ± 0.027×1018 kg[6]
Mean density
 2.1+2.6
−1.2 g/cm3[7]
Albedo 0.10–0.25, assuming density 0.5–2.0 g/cm3[6]
5.86

    66652 Borasisi /ˌbɒrəˈsiːsi/ is a binary classical Kuiper belt object. It was discovered in 1999 by Chad Trujillo, Jane X. Luu and David C. Jewitt[4] and identified as a binary in 2003 by K. Noll and colleagues[4] using the Hubble Telescope.

    Satellite

    Schematic illustration of two bodies with similar mass orbiting around a common barycenter (red cross) with elliptic orbits. Borasisi and Pabu interact similarly.

    In 2003 it was discovered that 66652 Borasisi is a binary with the components of comparable size (about 120–180 km) orbiting the barycentre on a moderately elliptical orbit.[8] The total system mass is about 3.4 × 1018 kg.[6]

    The companion (66652) Borasisi I, named Pabu /ˈpɑːbuː/ orbits its primary in 46.2888 ± 0.0018 days on an orbit with semi-major axis of 4528 ± 12 km and eccentricity 0.4700 ± 0.0018. The orbit is inclined with respect to the observer by about 54° meaning that is about 35° from the pole-on position.[6]

    Naming

    Borasisi is named after a fictional creation deity taken from the novel Cat's Cradle by Kurt Vonnegut.[9] In the book, Borasisi is the Sun and Pabu is the name of the Moon:[10]

    Borasisi, the sun, held Pabu, the moon, in his arms and hoped that Pabu would bear him a fiery child. But poor Pabu gave birth to children that were cold, that did not burn... Then poor Pabu herself was cast away, and she went to live with her favorite child, which was Earth.

    Exploration

    Around 2005, Borasisi was considered as a target for the proposed New Horizons 2 after a Triton/Neptune flyby.[11]

    References

    1. ↑ "MPEC 2009-R09 :Distant Minor Planets (2009 SEPT. 16.0 TT)". IAU Minor Planet Center. 2009-09-04. Retrieved 2009-10-04.
    2. ↑ (66652) Borasisi = 1999 RZ253 Orbit
    3. ↑ Marc W. Buie (2008-05-01 using 39 observations). "Orbit Fit and Astrometric record for 66652". SwRI (Space Science Department). Retrieved 2009-10-04. Check date values in: |date= (help)
    4. ↑ 4.0 4.1 4.2 "JPL Small-Body Database Browser: 66652 Borasisi (1999 RZ253)". Retrieved 2009-05-13.
    5. ↑ Wm. Robert Johnston (2008-11-25). "(66652) Borasisi". Johnston's Archive. Retrieved 2009-10-06.
    6. ↑ 6.0 6.1 6.2 6.3 6.4 Grundy, W. M.; Noll, K. S.; Nimmo, F.; Roe, H. G.; Buie, M. W.; Porter, S. B.; Benecchi, S. D.; Stephens, D. C.; Levison, H. F.; Stansberry, J. A. (2011). "Five new and three improved mutual orbits of transneptunian binaries" (PDF). Icarus 213 (2): 678. arXiv:1103.2751. Bibcode:2011Icar..213..678G. doi:10.1016/j.icarus.2011.03.012.
    7. ↑ TNOs are Cool: A survey of the trans-Neptunian region. X. Analysis of classical Kuiper belt objects from Herschel and Spitzer observations p. 18
    8. ↑ Keith S. Noll; Denise C. Stephens; Will M. Grundy & Ian Griffin (December 2004). "The orbit, mass, and albedo of transneptunian binary (66652) 1999 RZ253". Icarus 172. arXiv:astro-ph/0406588. Bibcode:2004Icar..172..402N. doi:10.1016/j.icarus.2004.06.009.
    9. ↑ Michael E. Brown, How I Killed Pluto and Why It Had It Coming. ch. 11 "Planet or Not"
    10. ↑ JPL Small-Body Database Browser
    11. ↑ Final Report of the New Horizons II Review Panel

    External links