1. Eris
,

2. Eris, a dwarf planet…
Eris, with the formal designation 136199 Eris, is
the largest dwarf planet of our Solar System. It is
a trans-neptunium object.

3. Eris, a dwarf planet…

4. The Discovery of Eris…
Eris was discovered by Mike Brown, Chad Trujillo
and David Rabinowitz’s team on 5th January
2005, from images taken on 21st October 2003.
The discovery was announced on 29th July
2005, the same day as Makemake and two days
after Haumea.

5. The Orbit of Eris…
• Eris has an orbital period of 557 years and as
for 2011 it lies 96,6 astronomical units from
the Sun, almost its maximum possible
distance to orbit the Sun.

6. The Moon of Eris…
Images taken on 10th September 2005 revealed
a moon in orbit around Eris. Instead of keeping
the name “Xena”, a nickname already in use for
Eris, Brown's team nicknamed this moon
“Gabrielle”. In a conference of the IAU
(International Astronomical Unit), Eris receives
its official name and its moon receives the name
Dysnomia.

8. Surface and Atmosphere…
Due to the fact that this dwarf planet is in the
limit of the Solar System, it has got negative
temperatures. The medium temperature to the
surface of Eris is -270oC to -217oC.

9. Bibliografy:
• http://en.wikipedia.org/wiki/File:2006-16-a-full-1-.jpg;
• http://en.wikipedia.org/wiki/Eris_(dwarf_planet);
• http://1.bp.blogspot.com/_n6b9oN2a7Ww/TCpQxM9IIHI/AA
AAAAAABK0/rZjzxNs8oPs/s1600/%C3%89ris.jpg;
• Geografia Universal – A Astronomia e o Sistema Solar, 2005,
de Iniziative Speciali De Agostini;
• http://www.astronomytoday.com/astronomy/eris.html;
• www.explicatorium.pt/c-f-q-7_ano/astronomia/eris/;
• Dicionário por Imagens do Sistema Solar, 1998, de Agnès
Vandewiele;