(136472) Makemake (North Up, East Left)
Makemake was discovered on 31 March 2005, by a team at the Palomar Observatory, led by Michael E. Brown,and was announced to the public on 29 July 2005. 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, 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. The provisional designation 2005 FY9 was given to Makemake when the discovery was made public. In July 2008, in accordance with IAU rules for classical Kuiper belt objects, 2005 FY9 was given the name of a creator deity.The name of Makemake, the creator of humanity and god of fertility in the myths of the Rapa Nui, the native people of Easter Island. At the date of observation Makemake was 52.5 AU from the Sun, almost as far from the Sun as it ever reaches on its orbit (52.8 AU).  Makemake follows an orbit very similar to that of Haumea: highly inclined at 29° and a moderate eccentricity of about 0.16.Nevertheless, Makemake's orbit is slightly farther from the Sun in terms of both the semi-major axis and perihelion. Its orbital period is nearly 310 years,more than Pluto's 248 years and Haumea's 283 years. Both Makemake and Haumea are currently far from the ecliptic - Makemake is approaching its 2033 aphelion, whereas Haumea passed its aphelion in early 1992. Makemake is a classical Kuiper belt object (KBO),which means its orbit lies far enough from Neptune to remain stable over the age of the Solar System.Unlike plutinos, which can cross Neptune's orbit due to their 2:3 resonance with the planet, the classical objects have perihelia further from the Sun, free from Neptune's perturbation. Such objects have relatively low eccentricities (e below 0.2) and orbit the Sun in much the same way the planets do. Makemake, however, is a member of the "dynamically hot" class of classical KBOs, meaning that it has a high inclination compared to others in its population. Makemake is, probably coincidentally, near the 11:6 resonance with Neptune. Combining the detection in infrared by the Spitzer Space Telescope and Herschel Space Telescope with the similarities of spectrum with Pluto yielded an estimated diameter from 1,360 to 1,480 km. This means that Makemake is slightly larger than that of Haumea, making it likely the fourth- largest known trans-Neptunian object after Pluto, Eris, and 2007 OR10, though the error bars with the latter overlap.  Makemake was the fourth dwarf planet recognized, because it has a bright V-band absolute magnitude of −0.44 and high geometrical albedo of 0.81. The rotation period of Makemake is estimated at 7.77 hours, with amplitude of 0.03 mag.  Like Pluto, Makemake appears red in the visible spectrum, and significantly redder than the surface of Eris (see colour comparison of TNOs). The near-infrared spectrum is marked by the presence of the broad methane (CH4) absorption bands. Methane is observed also on Pluto and Eris, but its spectral signature is much weaker. Spectral analysis of Makemake's surface revealed that methane must be present in the form of l arge grains at least one centimetre in size.In addition to methane, large amounts of ethane and tholins as well as smaller amounts of ethylene, acetylene and high-mass alkanes (like propane) may be present, most likely created by photolysis of methane by solar radiation.The tholins are probably responsible for the red color of the visible spectrum. Although evidence exists for the presence of nitrogen ice on its surface, at least mixed with other ices, there is nowhere near the same level of nitrogen as on Pluto and Triton, where it composes more than 98 percent of the crust. The relative lack of nitrogen ice suggests that its supply of nitrogen has somehow been depleted over the age of the Solar System. The far-infrared and submillimeter photometry performed by Spitzer and Herschel telescopes revealed that the surface of Makemake is not homogeneous. Although the majority of it is covered by nitrogen and methane ices, where the albedo ranges from 78 to 90%, there are small patches of dark terrain whose albedo is only 2 to 12%.  These studies were made before S/2015 (136472) 1 was discovered; thus, these small dark patches may actually have been the dark surface of the satellite rather than any actual surface features on Makemake.However, another experiment has refuted these studies. Between 2006 and 2013, the Telescopio Nazionale Galileo acquired new visible and near infra-red spectra for Makemake that covered nearly 80% of its surface; this study found that the variation in the spectra were negligible, suggesting that Makemake's surface may indeed be homogenous. Makemake was expected to have an atmosphere similar to that of Pluto but with a lower surface pressure. However, on 23 April 2011 Makemake passed in front of an 18th-magnitude star and abruptly blocked its light.The results showed that Makemake presently lacks a substantial atmosphere.  The presence of methane and possibly nitrogen suggests that Makemake could have a transient atmosphere similar to that of Pluto near its perihelion. Nitrogen, if present, will be the dominant component of it. The existence of an atmosphere also provides a natural explanation for the nitrogen depletion: because the gravity of Makemake is weaker than that of Pluto, Eris and Triton, a large amount of nitrogen was probably lost via atmospheric escape; methane is lighter than nitrogen, but has significantly lower vapor pressure at temperatures prevalent at the surface of Makemake, which hinders its escape; the result of this process is a higher relative abundance of methane.  However, studies of Pluto's atmosphere by New Horizons suggest that methane, not nitrogen, is the dominant escaping gas, suggesting that Makemake's absence of nitrogen may be more complicated. This image comprises 5 x Luminance (120 seconds each) , 0.5m f/2.9 ASA Astrograph with FLI ML3200 camera at an altitude of 65 degrees on 29 March 2017, 6 days after opposition at magnitude 16.7. The field of view is 18’ x 18’.
Hills Observatory: 1 January 2013 to 6 May 2018
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