2005: 10th planet found..2003 UB313 aka Eris
Eris, the largest dwarf planet known, was discovered in an ongoing survey at Palomar Observatory’s Samuel Oschin telescope by astronomers Mike Brown (Caltech), Chad Trujillo (Gemini Observatory), and David Rabinowitz (Yale University). We officially suggested the name on 6 September 2006, and it was accepted and announced on 13 September 2006. In Greek mythology, Eris is the goddess of warfare and strife. She stirs up jealousy and envy to cause fighting and anger among men. At the wedding of Peleus and Thetis, the parents of the Greek hero Achilles, all the gods with the exception of Eris were invited, and, enraged at her exclusion, she spitefully caused a quarrel among the goddesses that led to the Trojan war. In the astronomical world, Eris stirred up a great deal of trouble among the international astronomical community when the question of its proper designation led to a raucous meeting of the IAU in Prague. At the end of the conference, IAU members voted to demote Pluto and Eris to dwarf-planet status, leaving the solar system with only eight planets.
The satellite of Eris has received the offical name Dysnomia, who in Greek mythology is Eris’ daughter and the demon spirit of lawlessness. As Dysnomia is a bit of a mouthful, we tend to simply call the satellite Dy, for short.
As promised for the past year, the name Xena (and satellite Gabrielle) were simply placeholders while awaiting the IAU’s decision on how an official name was to be proposed. As that process dragged on, however, many people got to know Xena and Gabrielle as the real names of these objects and are sad to see them change. We admit to some sadness ourselves.We used the names for almost two years now and are having a hard time swtiching. But for those who miss Xena, look for the obvious nod in the new name of the moon of Eris.
Eris, minor-planet designation 136199 Eris, is the most massive known dwarf planet in the Solar System and the ninth most massive body known to orbit the Sun directly. It is estimated to be 2326 (±12) km in diameter, and 27% more massive than Pluto, or about 0.27% of the Earth’s mass.
Eris was discovered in January 2005 by a Palomar Observatory-based team led by Mike Brown, and its identity was verified later that year. It is a trans-Neptunian object (TNO) and a member of a high-eccentricity population known as the scattered disc. It has one known moon, Dysnomia. As of 2013, its distance from the Sun is 96.4 AU, roughly three times that of Pluto. With the exception of some comets, Eris and Dysnomia are currently the most distant known natural objects in the Solar System.
Because Eris appeared to be larger than Pluto, its discoverers and NASA initially described it as the Solar System’s tenth planet. This, along with the prospect of other similarly sized objects being discovered in the future, motivated the International Astronomical Union (IAU) to define the term planet for the first time. Under the IAU definition approved on August 24, 2006, Eris is a “dwarf planet”, along with objects such as Pluto, Ceres, Haumea and Makemake.
In 2010, preliminary results from observations of a stellar occultation by Eris on November 6 suggested that its diameter may be only 2,326 km, which would make it essentially the same diameter as Pluto. Given the error bars in the different size estimates, it is currently uncertain whether Eris or Pluto has the larger diameter. Both Pluto and Eris are estimated to have solid-body diameters of about 2330 km.
Because Eris may be larger than Pluto, it was initially described as the “tenth planet” byNASA and in media reports of its discovery. In response to the uncertainty over its status, and because of ongoing debate over whether Pluto should be classified as a planet, the IAU delegated a group of astronomers to develop a sufficiently precise definition of the term planet to decide the issue. This was announced as the IAU’s Definition of a Planet in the Solar System, adopted on August 24, 2006. At this time, both Eris and Pluto were classified as dwarf planets, a category distinct from the new definition of planet. Brown has since stated his approval of Pluto losing its status as a planet. The IAU subsequently added Eris to its Minor Planet Catalogue, designating it (136199) Eris.
this story comes via my 6 year old..he had been up at the local second hand book store with his mum and had grabbed a magazine about space written in 2005 and it seems they were hunting PX even then..he walked up to me and asked..how many plants are there dad? and i said 9 and he said no..there is 10..and presented the magazine to me..so a bit of searching and it reveals that this body WAS thought to be the 10th planet..the PX or nibiru that we see so much of these days..it was eventually called a dwarf planet and along with pluto it was downgraded to a minor planet status..so there are now only 8 official planets that we recognize..eris was named, as are most of the celestial bodies..after greek or roman gods..because its all written in the stars..
the picture above is from the actual magazine cover..the gif is eris..
“Eris is the goddess of warfare and strife. She stirs up jealousy and envy to cause fighting and anger among men.”