Eris

Erisi (alama: ;^[1] pia (136199) Erisi au 136199 Erisi) ni sayari kibete kubwa inayojulikana katika mfumo wa Jua letu.

Njia yake ya kuzunguka jua ni nje ya njia ya Pluto. Eros inaonekana ina angalau mwezi mmoja unaoitwa Dysnomia. Makadirio ya kipenyo chake ni 2400 km ambacho ni kikubwa kidogo kuliko Pluto. Inazunguka jua katika muda wa miaka 556.7 ya dunia. Umbali wake na jua ni mara 97 umbali wa dunia yetu. Kutoka Erisi hata jua letu laonekana kama nyota ndogo tu.

Erisi ilitambuliwa 2005 na wanaastronomia walioongozwa na Dr. Michael E. Brown kwenye paoneaanga Mount Palomar (Marekani). Walichungulia picha za anga zilizopigwa mwaka 2003 wakatambua nukta ya anga lililobadilika mahali.

Kutambuliwa kwa Erisi kulisababisha wanafalaki kuanzisha kitengo kipya cha "sayari kibete". Brown aliwahi kutangaza Erisi kuwa sayari ya kumi ya jua letu. Lakini wataalamu wengine waliona uwezekano mkubwa ya kwamba magimba mengine ya kufanana na Erisi yatapatikana karibuni. Maana ya neno "sayari" kwa kulingana na sayari za ndani ilihofiwa kutavurugika. Hivyo utaratibu wa sayari kibete ulianzishwa.

Hivyo Erisi ilikuwa sababu ya kushushwa kwa cheo cha Pluto ambayo ni ndogo kuliko Erisi.

• [http://www.gps.caltech.edu/~mbrown/planetlila/ Michael Brown's webpage about
• [http://www.gps.caltech.edu/~mbrown/planetlila/moon/ Tovuti ya Brown kuhusu mwezi wa Eris
• compiled list of data
• MPEC listing
• Java 3D orbit visualization
• Spaceflight Now article
• Slacker Astronomy Interview With Co-Discoverer Trujillo
• NASA - new planet discovered
• Trans-Neptunian Object mp|2003 UB|313 — IAU statement regarding the planetary status of Eris
• Simulation of mp|2003 UB|313's orbit — mp|2003 UB|313 is in a 17:5 resonance with Neptune
• Keck observatory page about the discovery of mp|2003 UB|313's moon
• Parade Magazine on the spacecraft New Horizons
• M. E. Brown et al., Satellites of the largest Kuiper belt objects, Astrophysics Journal Letters, 25 Desemba 2005 preprint

• Tenth planet discovered in outer solar system - NewScientistSpace.com
• Astronomers Discover "10th Planet" Ilihifadhiwa 3 Desemba 2008 kwenye Wayback Machine. - Sky & Telescope article
• Tenth Planet Discovered - Astronomy Magazine article
• LARGER THAN PLUTO! 10th Planet Discovered? - Planetary Society
• Tenth planet found! - spaceflightnow.com
• Object Bigger than Pluto Discovered, Called 10th Planet - space.com
• Astronomers detect '10th planet' - BBC News
• You Call That a Planet? How astronomers decide whether a celestial body measures up. Ilihifadhiwa 5 Agosti 2005 kwenye Wayback Machine. - Slate.com
• Hubblesite:Revised diameter (April 2006)
• A Dwarf Planet Is Named: Eris - New York Times

1. ↑ JPL/NASA (2015-04-22). "What is a Dwarf Planet?". Jet Propulsion Laboratory. Iliwekwa mnamo 2022-01-19.