Changes

Eris was first photographed on October 21, 2003, but was at first too slow-moving for the Palomar Observatory image-analytic software to detect. Later, [[Michael E. Brown]], [[Chad Trujillo]], and [[David Rabinowitz]] ordered  re-analysis of the images with greater sensitivity. They soon realized that the images depicted a new object, and announced their findings on January 5, 2005.

Eris was first photographed on October 21, 2003, but was at first too slow-moving for the Palomar Observatory image-analytic software to detect. Later, [[Michael E. Brown]], [[Chad Trujillo]], and [[David Rabinowitz]] ordered  re-analysis of the images with greater sensitivity. They soon realized that the images depicted a new object, and announced their findings on January 5, 2005.

The initial name for the new object was Xena, the title character in an [[United States|American]] [[television]] action-adventure dramatic series,<ref>The character is supposed to be a princess from a tribe of warriors, either Argive or closely allied with them, in the days of the Mycenean civilization, and a contemporary of, and occasional rival to, Hercules. No historical warrant exists for the existence of such a person or even for a classical poem mentioning that name.</ref> and also a name beginning with X, in keeping with the suspicion that this object was the long-sought "Planet X." But the announcement of Eris' discovery on July 29, 2005 presented the [[International Astronomical Union]] with an embarrassing problem.<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/eris.htm Entry for 'Eris']." ''Views of the Solar System'', 2007. Accessed January 21, 2008.</ref> Other observations<ref name=Ingham>Ingham, Richard. "[http://www.abc.net.au/science/news/stories/s1560563.htm 'Tenth planet' Xena bigger than Pluto]." Agence France-Presse, quoted by Australian Broadcasting Corporation, February 2, 2006. Accessed May 15, 2008.</ref><ref name=solstation>[http://www.solstation.com/stars/UB313.htm Eris (2003 UB₃₁₃) and Dysnomia]. Accessed January 22, 2008.</ref> had already suggested that 2003 UB₃₁₃ might be more massive even than [[Pluto]], then considered the ninth [[planet]] in the [[solar system]]. Because planets and Kuiper-Belt objects have different naming conventions, and because [[scattered disk]] objects had ''no'' naming convention at the time, the names for these two objects remained unofficial.<ref name=Tytell>Tytell, David. "[http://www.skyandtelescope.com/news/home/3916126.html All Hail Eris and Dysnomia]." ''Sky and Telescope'', September 14, 2006. Accessed May 15, 2008.</ref>

The initial name for the new object was Xena, the title character in an [[United States|American]] [[television]] action-adventure dramatic series,<ref>The character is supposed to be a princess from a tribe of warriors, either Argive or closely allied with them, in the days of the Mycenean civilization, and a contemporary of, and occasional rival to, Hercules. No historical warrant exists for the existence of such a person or even for a classical poem mentioning that name.</ref> and also a name beginning with X, in keeping with the suspicion that this object was the long-sought "Planet X." The object also had a satellite, which the discoverers tentatively named Gabrielle, after the supporting character in that dramatic series.

 

The announcement of Eris' discovery on July 29, 2005 presented the [[International Astronomical Union]] with an embarrassing problem.<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/eris.htm Entry for 'Eris']." ''Views of the Solar System'', 2007. Accessed January 21, 2008.</ref> Other observations, specifically of the period and orbital characteristics of the satellite,<ref name=Ingham>Ingham, Richard. "[http://www.abc.net.au/science/news/stories/s1560563.htm 'Tenth planet' Xena bigger than Pluto]." Agence France-Presse, quoted by Australian Broadcasting Corporation, February 2, 2006. Accessed May 15, 2008.</ref><ref name=solstation>[http://www.solstation.com/stars/UB313.htm Eris (2003 UB₃₁₃) and Dysnomia]. Accessed January 22, 2008.</ref> had already suggested that 2003 UB₃₁₃ might be more massive even than [[Pluto]], then considered the ninth [[planet]] in the [[solar system]]. Because planets and Kuiper-Belt objects have different naming conventions, and because [[scattered disk]] objects had ''no'' naming convention at the time, the names for the new primary and satellite remained unofficial.<ref name=Tytell>Tytell, David. "[http://www.skyandtelescope.com/news/home/3916126.html All Hail Eris and Dysnomia]." ''Sky and Telescope'', September 14, 2006. Accessed May 15, 2008.</ref>

Finally the [[International Astronomical Union]] declared<ref>"[http://www.iau.org/iau0602.423.0.html IAU0602: the Final IAU Resolution on the Definition of 'Planet' Ready for Voting]," ''International Astronomical Union'', 2005. Accessed January 14, 2008.</ref> that Pluto and 2003 UB₃₁₃ were not planets, but belonged to a new category called [[dwarf planet]]s. Then on September 6, 2006, Mike Brown and his team<ref name=Brown4>Brown, Mike. "[http://www.gps.caltech.edu/%7Embrown/planetlila/index.html The discovery of Eris, the largest known dwarf planet]." California Institute of Technology. Accessed January 22, 2008.</ref> recognized that the name "Xena" was inappropriate for 2003 UB₃₁₃ and suggested to the IAU that they name it Eris, after the Greek goddess of discord and strife. They also suggested that the IAU name the satellite Dysnomia, for the Greek goddess of lawlessness and daughter of Eris.<ref>Dysnomia, meaning "lawlessness," is also a play on the name of the American actress who portrayed Xena, Lucy Lawless.</ref> Four days later, the IAU oficially named the primary Eris and named its satellite Dysnomia.<ref name=IAU2>[http://cfa-www.harvard.edu/iau/special/08747.pdf IAU Circular No. 8747], International Astronomical Union, September 10, 2006. Accessed May 15, 2008.</ref>

Finally the [[International Astronomical Union]] declared<ref>"[http://www.iau.org/iau0602.423.0.html IAU0602: the Final IAU Resolution on the Definition of 'Planet' Ready for Voting]," ''International Astronomical Union'', 2005. Accessed January 14, 2008.</ref> that Pluto and 2003 UB₃₁₃ were not planets, but belonged to a new category called [[dwarf planet]]s. Then on September 6, 2006, Mike Brown and his team<ref name=Brown4>Brown, Mike. "[http://www.gps.caltech.edu/%7Embrown/planetlila/index.html The discovery of Eris, the largest known dwarf planet]." California Institute of Technology. Accessed January 22, 2008.</ref> recognized that the name "Xena" was inappropriate for 2003 UB₃₁₃ and suggested to the IAU that they name it Eris, after the Greek goddess of discord and strife. They also suggested that the IAU name the satellite Dysnomia, for the Greek goddess of lawlessness and daughter of Eris.<ref>Dysnomia, meaning "lawlessness," is also a play on the name of the American actress who portrayed Xena, Lucy Lawless.</ref> Four days later, the IAU oficially named the primary Eris and named its satellite Dysnomia.<ref name=IAU2>[http://cfa-www.harvard.edu/iau/special/08747.pdf IAU Circular No. 8747], International Astronomical Union, September 10, 2006. Accessed May 15, 2008.</ref>