Haumea

Opening

Haumea was discovered independently by American and Spanish groups of astronomers.

The American group consisted of: Michael Brown ( California Institute of Technology ), David Rabinowitz ( Yale University ) and Chadwick Trujillo ( Gemini Observatory ). They discovered Haumea on December 28, 2004 in a photograph taken on May 6, 2004 by the 122-cm telescope named after Samuel Oshin , which is located in the Palomar Observatory ^[10] . Instead of immediately publishing his discovery, Brown decided to first study in detail the nature of the object ^[11] . By July 7, 2005, he had prepared documents for the announcement of the discovery, but because of the birth of his daughter, he postponed it until the Congress of the American Astronomical Union in September 2005, publishing a brief review of the report on July 20, 2005 ^[12] .

The Spanish group included ( ) and his student Pablo Santos Sanz. They discovered Haumea on July 25, 2005 in a photograph taken by Francisco Aceituno on March 7, 2003 using a 36-cm telescope at the Sierra Nevada Observatory . On July 28, the discovery was confirmed at the Mallorca Observatory , having detected the object using a 30-cm telescope.

The Spanish group officially announced its discovery on July 29, 2005 ^[13] , thus becoming the official discoverer.

Brown, having learned about the announcement of the discovery, immediately sent his details for publication and sent Ortiz an email of congratulation ^[11] . However, he soon suspected Ortiz of forgery, because two days before the Spaniards announced the discovery, someone from the Andalusian Astrophysical Institute looked at the Haumea images taken by the Brown group, and on August 14, 2005 filed a complaint with the IAU ^{[12] [14]} . Ortiz later confirmed that he was browsing Brown’s materials, but solely to verify his discovery ^[15] .

Title

When registering the opening, the object was assigned the designation 2003 EL ₆₁ , corresponding to the date of the picture in which the object was opened by a Spanish group.

Before the discovery of the discovery by the Spanish group, American astronomers used the technical code K40506A ^[16] for the object, but between them gave it the nickname “ Santa ”, since it was discovered immediately after Christmas 2004 ^[11] .

September 7, 2006, simultaneously with Pluto and Eris, he was included in the catalog of minor planets under the number 136108 ^[17] .

The Spaniards proposed giving the planet the name Ataecina ( lat. Ataecina ) - in honor of the Iberian goddess of spring, which is considered an analogue of the Roman Proserpine ^[18] . However, this option was not accepted, since the names of the underground gods are “reserved” for objects whose orbits, like the orbit of Pluto, gravitationally interact with Neptune ^[19] . In accordance with the rules of the MAC, the classical objects of the Kuiper belt are given a name associated with the creation ^[19] . David Rabinowitz proposed to be named after Haumea , the Hawaiian goddess of fertility and procreation ^[20] .

September 17, 2008 2003 EL ₆₁ was named Haumea ( lat. Haumea ) ^[21] . Along with the naming, it was included in the number of dwarf planets, becoming the fifth dwarf planet and the fourth plutoid, along with Pluto , Eris and Makemake ^{[8] [22]} .

The Haumei orbit is traced from archival images until 1955 ^[23] . It is inclined to the ecliptic plane at an angle of 28.2 °, moderately elongated - its eccentricity is 0.1920. The semimajor axis of the orbit is 43.29 a.u. (6.48 billion km.), While the maximum distance from Haumea to the Sun is 51.60 AU (7.72 billion km.), And the minimum - 34.97 AU (5.23 billion km.) ^[23] . Therefore, Haumea does not enter the orbit of Neptune .

Initially, Haumei was attributed to the classical objects of the Kuiper belt (also called kyubivano) ^[24] , but later the TsMP excluded it from this group ^[25] . This is due to the fact that Haumea discovered the possibility of its weak interaction with Neptune at a resonance of 12: 7 ^[26] .

As of 2019, Haumea is at 50.40 AU (7.54 billion km.) From the Sun ^[27] , near the point of aphelion, which it passed in late 1991 - early 1992, and is now approaching the Sun ^[27] .

The absolute stellar magnitude of Haumea is 0.2 ^{m [23]} Its visible brilliance in 2019 is 17.4 ^{m [28]} . It is bright enough to be photographed through a powerful amateur telescope with an aperture of 250-300 mm. ^[29]

The period of revolution of the Haumea around the Sun is 281.8 years. Accordingly, the closest passage of perihelion will occur in 2132 ^[23] .

According to calculations, the duration of a flight of an automatic interplanetary station to study Haumea from a flight path would be about 15 years using the gravitational maneuver near Jupiter. So, when launched on September 25, 2025, the flight will take 14.25 years, and when launched on November 1, 2026, September 23, 2037, or October 29, 2038, it will be 16.45 years ^[30] .

The first photometric observations made by the Brown team in 2005 through a telescope at the Keck Observatory revealed that Haumea is an unusual planet. It rotates extremely fast - its rotation period around its own axis is 3.9155 ± 0.0002 hours ^[9] .

The very fast rotation of Haumea should distort its shape. This is indirectly confirmed by the fact that she has large fluctuations in brightness - their amplitude reaches (0.28 ± 0.04) ^{m [9]} . Although the cause of these fluctuations may be surface inhomogeneity (as in Pluto, where the deviations in brightness reach 35%), for Haumea the reason for the brightness change is most likely its elongated shape ^[31] . The researchers conducted a simulation of the shape of the object, establishing that the best fit is given by a model in the form of a Jacobi ellipsoid with dimensions of 1960 × 1518 × 996 km and an albedo of 0.73 ^[9] . In this case, the size of Haumea is approximately the diameter of Pluto “along” and half as much “across”, and Haumea takes the third or fourth place among the trans-Neptune objects after Eris , Pluto and, possibly, Makemake .

In 2007, Haumea's diameter and albedo measurements were published using the Spitzer infrared space telescope . According to these measurements, the average diameter of Haumea turned out to be 1150 +250
−100 km, and the albedo - 0.84 +0.10
−0.20 ^[32] .

Measurements of the size of the object, carried out in 2009 using the Herschel infrared space observatory , showed that its average diameter lies in the range of 1212–1491 km ^[3] .

The Haumea mass is determined from the orbits of the satellites and is equal to (4.004 ± 0.040) ⋅10 ²¹ kg ^[33] , which is 24% of the mass of Eris and 32% of the mass of Pluto, but 4 times the mass of Ceres . Based on the calculated shape of the object, its average density in 2006 was estimated at 2.6-3.34 g / cm³. ^[9] Thus, the Haumea density is higher than that of its neighbors in the Kuiper belt. In 2007, 2010 and 2014, the Haumea density was estimated at 2.5–2.6 g / cm³ ^{[3] [34] [2]} .

The inclination of the axis of rotation of Haumea to the plane of its orbit is unknown ^[35] , which further complicates the determination of the shape of the object.

After January 21, 2017, Haumea covered the star URAT1 533-182543 , it was possible to clarify the parameters of the dwarf planet. The largest axis of the ellipsoid is at least 2322 km (2322 × 1701 × 1138 km), density - no more than 1.757-1.885 g / cm³, geometric albedo - 0.51 ± 0.02 ^[1] .

In January 2017, the discovery of rings at Haumea became known, and in October, the discovery was published ^[1] . Their radius is approximately 2287 km, with a width of about 70 km ^[36] and a transparency of 0.5. The plane of the ring approximately coincides with the equatorial plane of Haumea and the orbital plane of its larger moon Hiiaka. The ring is also close to the 3: 1 resonance with the rotation of Haumea (which is located in a radius of 2,288 ± 8 km). The ring makes up about 5% of the total brightness of Haumea ^{[37] [38]} .

Haumea became the first TNO with a ring system.

In 2005, the Haumea spectrum was studied in the range 1.0–2.4 μm using telescopes at the Gemini and Keck observatories. As a result, it was found that its surface, like that of Charon , is covered mainly with water ice in the form of grains with a diameter of 25 or 50 μm. But the spectrum of the object is different from the spectrum of pure ice - it contains features that researchers are inclined to explain by the presence on the surface of hydrogen cyanide (up to 27%) and phyllosilicate rocks such as kaolinite . Also, in the Haumea spectrum, a decrease was found, unusual for crystalline ice, after 2.35 μm, which may be due to the presence of potassium cyanide in its snow, or carbonaceous minerals such as asphaltite , kerite, or wurtzylite ^[39] .

In 2009, Pedro Lacerda from Queen's University in Belfast announced the discovery of a color anomaly on the surface of Haumea - a large spot with a red tint in the visible range. The nature and origin of this object is not precisely established. Presumably, this may be a region of accumulation of certain minerals or organic compounds ^{[31] [40]} . According to another hypothesis, the “red spot” is a trace of the collision of Haumea with another celestial body ^{[41] [42]} .

Perhaps Haumea was born as a result of the collision of two celestial bodies. Most of the light components (methane and nitrogen) after the impact partially evaporated, partially ejected into the surrounding space and subsequently formed two satellites (possibly more satellites will be discovered). The collision hypothesis is indirectly confirmed by the fact that at least three more TNOs of smaller size with similar Haumea spectra, which may be “fragments” of Haumea and an object with a diameter of about 1,600 km, collapsed in similar orbits. Two other TNO “fellow travelers” ^[43] , which were previously considered “fragments”, have a reddish color and therefore do not belong to the participants in this cataclysm. The search for “fragments” continues ^[44] .

After the discovery of Haumea, the Brown group began systematic observations of it through a telescope with adaptive optics at the Keck Observatory and on January 26, 2005, they discovered a satellite at the object, nicknamed Rudolph, in honor of one of the deer in the Santa Claus team ^{[45 ]} . The second satellite, nicknamed Blitzen, was discovered in the same way on June 30, 2005 ^{[45] [46]} . On September 17, 2008, simultaneously with the assignment of the name of Haumea, its companions also received official names: Hiiaka (designation (136108) Haumea I Hiʻiaka) and Namaka (designation (136108) Haumea II Namaka) - in honor of the daughters of Haumea.

The diameter of Hiiaki is about 350 km, the circulation period is 48.9 days, the radius of the orbit is 49.9 thousand km. Namak is approximately half the size of the first, orbits around Haumea with a major semi-axis of 25.6 thousand km with a period of 18 days ^[33] .

• V.S. Uralskaya. Haumea (Haumea) (136108) 2003 EL61 (neopr.) . GAISH MSU . Date of treatment January 25, 2012. Archived on May 10, 2012.