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Makemake (dwarf planet)

Makemake
Makemake moon Hubble image with legend (cropped).jpg
Makemake and its moon, as seen by the Hubble Space Telescope
Discovery
Discovered by
Discovery date March 31, 2005
Designations
MPC designation (136472) Makemake
Pronunciation /ˌmækiˈmæki/, /ˌmɑːkiˈmɑːki/ or Listeni/ˌmɑːkˈmɑːk/
Named after
Makemake
2005 FY9
Dwarf planet
cubewano
scattered-near
Adjectives Makemakean
Orbital characteristics
Epoch JD 2457000.5 (9 December 2014)
Aphelion 52.840 AU
Perihelion 38.590 AU
45.715 AU
Eccentricity 0.15586
309.09 yr (112,897 d)
Average orbital speed
4.419 km/s
15
Inclination 29.00685°
79.3659°
297.240°
Known satellites 1
Physical characteristics
Dimensions
  • (1434+48
    −18
    ) × (1420+18
    −24
    km)
  • (1502±45) × (1430±9) km
Mean radius
  • 715+19
    −11
     km
  • 739±17 km
Flattening 0.05
(6.9±0.3)×106 km2
Volume (1.7±0.1)×109 km3
Mass < 4.4 × 1021 kg
Mean density
1.4–3.2 g/cm3 <3.05 g/cm3
Sidereal rotation period
7.771±0.003 h
Albedo 0.81+0.03
−0.05
Temperature 32–36 K (single-terrain model)
40–44 K (two-terrain model)
Spectral type
B−V=0.83, V−R=0.5
17.0 (opposition)
−0.3
S/2015 (136472) 1
Makemake with moon.JPG
Dwarf planet Makemake and its moon
Discovery
Discovered by
Discovery date April 2015
Designations
Pronunciation //
MK 2 (unofficial)
Orbital characteristics
21,000 km to 300,000 km
12.4 days to 660 days
Satellite of Makemake
Physical characteristics
Dimensions ~175 to 250 km
~0.1
25.1

Makemake (minor-planet designation 136472 Makemake) is a dwarf planet and perhaps the largest Kuiper belt object in the classical population, with a diameter approximately two thirds that of Pluto. Makemake has one known satellite, S/2015 (136472) 1. Makemake’s extremely low average temperature, about 30 K (−243.2 °C), means its surface is covered with methane, ethane, and possibly nitrogen ices.

Makemake was discovered on March 31, 2005, by a team led by Michael E. Brown, and announced on July 29, 2005. Initially, it was known as 2005 FY9 and later given the minor-planet number 136472. Makemake was recognized as a dwarf planet by the International Astronomical Union (IAU) in July 2008. Its name derives from Makemake in the mythology of the Rapa Nui people of Easter Island.

Makemake was discovered on March 31, 2005, by a team at the Palomar Observatory, led by Michael E. Brown, and was announced to the public on July 29, 2005. The team had planned to delay announcing their discoveries of the bright objects Makemake and Eris until further observations and calculations were complete, but announced them both on July 29 when the discovery of another large object they had been tracking, Haumea, was controversially announced on July 27 by a different team in Spain.

Despite its relative brightness (it is about a fifth as bright as Pluto), Makemake was not discovered until well after many much fainter Kuiper belt objects. Most searches for minor planets are conducted relatively close to the ecliptic (the region of the sky that the Sun, Moon and planets appear to lie in, as seen from Earth), due to the greater likelihood of finding objects there. It probably escaped detection during the earlier surveys due to its relatively high orbital inclination, and the fact that it was at its farthest distance from the ecliptic at the time of its discovery, in the northern constellation of Coma Berenices.


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