Eris, the Dwarf Planet
According to Wikipedia, a dwarf planet is a term created by the International Astronomical Union (IAU) to define a new class of celestial bodies. It was introduced into the IAU resolution of August 24, 2006, in the definition for “planet”.
Eris, a dwarf planet
In recent years there have been many objects of this class (which is already Pluto) but not all are as well known or have a proper name.
Among the largest are: Makemake, Haumea, Huya, Orcus, Quaoar, Ixion, Pluto, Eris, Salacia, Sedna and Varuna (the latter, has already been detected previously with the same equipment and was our first TNO).
In this case, we sought to detect Eris, formerly known as Xena and with a magnitude of 18.7. The two pictures shown, were taken with an Atik 314L + CCD coupled to a 25” reflector mounted on an equatorial mount.
After searching the exact coordinates of the object for a day and a specific time, we got down to work. It should be noted that this telescope has been substantially amended for accuracy at the cost of other amenities more useful for visual observation. For example, it has lost its GOTO capabilities and objects must to be searched through the eyepiece. After pointing, we switch to the CCD and try to identify the stars that appear on the screen with the area where the ephemeris point to the object. We have also elevated the telescope about 20 cm. It rests on the equatorial mount and the latter rests on a metal frame Which complicates comfortable observation for objects with an altitude above 70 degrees.
Animation in which the slight displacement of Eris can be appreciated with respect of the background stars
The first shot of the animated gif is the sum of 32 frames of 10 seconds and 4x4 binning, the exact date and time: August 9, 2013, 2:55:18 UT for the first underexposure. The second frame of the animated gif is the sum of other 32 exhibits the same characteristics beginning at 4:10:59 in the same day.
Both inputs are separated by only 75 minutes which explains the little apparent motion presented. We must keep in mind that it is an object that is 95 AU from us! and moving only 0.6"/ hour.
Job done. In future observations, we will try to hunt another one of these elusive objects.