90377 Sedna – Wikipedia

Posted on by
before-content-x4

Point
(90377 Sedna)

Sedna photographed by the Hubble Space Telescope

Mother star Sole
Discovery November 14, 2003
Discoverers Michael Brown
Chad Trujillo
David Rabinowitz
Classification Transnettunian object, sednoid
Ghost class ?
Designations
alternative 		2003 VB twelfth
Orbital parameters
(At the time JD 2458000.5
4 September 2017)
Major semiase 486,698 4232 At
( 72 809.047 78 × ten ^ 6  km)
Perihelion 76,059 2341 At
( 11 378,299 47 × ten ^ 6  km)
Afelles 897,337 6123 At
( 134 239,796 ten × ten ^ 6  km)
Orbital period 3 921 995.86 days
(10 737,8395 years)
Orbital speed first 040  m/s (media)
Inclination
on the ecliptic 		11,92897 °
Eccentricity 0.8437241
Length del
ascending knot 		144,45805 °
Argom. Perielio 311,59421 °
Media anomaly 358,02088 °
By. Weaver (t J ) 10,169 (calculated)
Next Perdie 2075− 2076
Physical data
Size first 180 -first 800  km
Pasta
Average density 2.0 × ten 3  kg/m³ ?
Acceleraz. of gravity on the surface 0,33–0,50 m/s²
Escape speed 620–950 m/s
Period of rotation 0.42 days
(10 ore)
Temperature
superficial 		~12 K (−261,1 °C) (media)
Albedo 0.32 ± 0.06
Observative data
Size app. 21.12
Size Ass. 1.5
Change data on wikidata · Manual
after-content-x4

Point (official name 90377 Sedna ) is a large transnettunian object that orbits around the sun on a particularly eccentric orbit that leads him to approach the external solar system near Perdielio and to leave up to beyond 5 days light ( 897 at ) from the sun when approaching the infelium. It is a cold planetoid, perhaps classifiable as a dwarf planet once the international astronomical union has examined its physical parameters, of approximately size equal to

2 / 3 {Displaystyle 2/3}

of those of Pluto.

The discoverers claim that Sedna is the first body of the Oort cloud to be observed, stating that it is too far from the sun to be considered an object of the Kuiper belt. However, it is much closer to the sun than you would expect from an object of the Oort cloud and its orbital inclination does not differ excessively from the ecliptic. So Sedna belongs to the cloud of internal oort, a relatively little thick region located on the level of the ecliptic and extended by the Kuiper belt to the cloud of external oort, spherical in shape. Other astronomers are limited to suggesting that previous hires about the outer edge of the Kuiper belt must be magazine.

Per Sedna, 2012 VP 113 and 541132 Leleāākūhonua, the only other objects known with comparable orbital parameters, the class of sednoids is defined, consisting of transnettunian objects with a perjustio greater than 50 at and a greater semiase greater than 150 at . [first]

However, even the same classification as a transnettunian object is contested, because Sedna never comes close enough to Neptune to be influenced by it. Others hypothesize that it could have been brought to its current orbit by a passage star, probably during the formation of the Solar System. Another hypothesis suggests that his orbit can be a test in support of a hypothetical great planet beyond the orbit of Neptune. The astronomer Michael E. Brown, Sedna and planets Consopropper Nani Eris, Humea and Makemake, believes that it is the most scientifically important transnettunian object found until today, since understanding the reason for its unusual orbit could provide valuable information on the ‘origin and the evolution of the Solar System. [2]

From 28 September to 26 November 2004, when 90528 Raywhite received the official name, it was the asteroid called with the highest ordinal number. Before its denomination, the primacy was 82232 Heuberger.

Its planetary symbol is ⯲. [3]

Sedna (in the center of the green circle).
Artistic representation of Sedna.

Sedna was discovered on November 14, 2003 by Michael Brown (California Institute of Technology), Chad Trujillo (Gemini Observatory) and David Rabinowitz (Yale University). Already at the time of the discovery it was at the greatest distance that any celestial body of the Solar System had ever been observed.

after-content-x4

Sedna was discovered during a detection conducted with the Samuel Oschin telescope of the Palomar Observatory, near San Diego (California). In the following days it was observed by telescopes in Chile, Spain, Arizona and Hawaii. The spatial telescope Spitzer, active in the infrared, was also aimed at the object without however being able to detect its electromagnetic radiation. It is therefore believed, based on the limits of resolution of the instrument, that the diameter of Sedna does not exceed first 800  km .

Because of its cold and distant nature and given the mythological nature of the names of the other planets of the Solar System, the discoverers have baptized the new celestial body as a sedna, the goddess Inuit of the sea, which is believed alive in the icy depth of the Army Ocean. On September 28, 2004 the international astronomical union, which previously identified the object with the provisional designation 2003 VB twelfth , approved the name.

Orbital parameters [ change | Modifica Wikitesto ]

Sedna moves on an extremely elliptical orbit with the aphelium located at about 900 at from the sun and perielio a 76 at . At the time of the discovery it was about 90 at from the sun and was being approached to Perdielio. It was the maximum distance of a body of the solar system from the ground at the time of discovery. The record was later beaten by Eris identified while he was a 97 at from the sun.

Sedna takes about ten 737 , 84 years old to describe a complete orbit around the sun; He will reach Perdio in 2075-76.

Surface [ change | Modifica Wikitesto ]

Animation of the orbit of sedna comparative to that of the planets of the Solar and Pluto system; Note the enormous distance of the object

Sedna diameter estimates oscillate between first 180 and 1 800  km ; It is the fifth Transnettunian object in order of magnitude among those known after Eris, Pluto, Makemake and Humea. The planetoid is so far from the sun that the surface temperature never goes up above the 23 K .

Observations made in Chile have shown that Sedna is one of the redest objects in the sun system, almost as much as Mars. Unlike Pluto and Caronte, Sedna seems to have very little frozen methane or water ice on its surface. Chad Trujillo and his colleagues from the Gemini Observatory in Hawaii have advanced a hypothesis that the reddish coloring of Sedna could be due to the presence of a hydrocarbon mud, the talina, similar to the one already found on Folo.

Sedna presents a homogeneous color and spectrum whose reason is probably to be found in the fact that the planetoid, unlike the objects closest to the sun, is much less exposed to the meteoric impacts that could locally change the albedo such as 8405 asbolus.

Sedna will reach Perdie in 2075–2076. This event will be a unique opportunity for exploration that will not be repeated if not between about twelfth 050 years , that is, until the year 14025. Although Sedna is mentioned on the exploration site of the NASA solar system, no mission has been scheduled. [4] It has been calculated that for a mission of Sorvolo in Sedna they would be used 24,480 years exploiting the slingshot effect of Jupiter, starting on May 6, 2033 or 23 June 2046. Sedna would be 77.27 o 76.43 at from the sun once reached. [5] If the launch of a hypothetical mission to Sedna took place in 2033, the planetoid could be reached in the year 2057 while, if the launch took place in 2046, the mission could reach the destination in the year 2070. The close study of Sedna would represent a The unique opportunity to analyze the farthest celestial body of the Solar System and understand if it has developed in the cloud of Oort and if its composition and its geophysical properties differ from the celestial bodies of the Kuiper belt. [6]

  1. ^ Scott S. Sheppard, Known Extreme Outer Solar System Objects . are Home.dtm.ciw.edu , Department of Terrestrial Magnetism, Carnegie Institution for Science. URL consulted on 28 September 2015 (archived by URL Original March 25, 2015) .
  2. ^ Cal Fussman, The Man Who Finds Planets . are Discovermagazine.com (archived by URL Original June 16, 2010) .
  3. ^ U+2BF2 ⯲. David Faulks (2016), Eris and Sedna Symbols , L2/16-173r ( PDF ). , Unicode Technical Committee Document Register.
  4. ^ In Solar System Exploration: Missions to Dwarf Planets . are solarsystem.nasa.gov (archived by URL Original on 9 August 2012) .
  5. ^ McGranahan, R., Sagan, B., Dove, G., Tullos, A., Lyne, J. E. E. Emery, J. P., A Survey of Mission Opportunities to Trans-Neptunian Objects , in Journal of the British Interplanetary Society , vol. 64, 2011, pp. 296–303, Bibcode: 2011JBIS…64..296M .
  6. ^ ( IN ) Ethan Siegel, Is Humanity Ignoring Our First Chance For A Mission To An Oort Cloud Object? . are Forbes , 22 Marzo 2018. URL consulted on April 5, 2020 ( filed December 14, 2019) .
after-content-x4