Scott Sheppard and Chad Trujillo Discover One of the Most Distant Comets to Show Activity

Sheppard Trujillo Comet
This image shows the comet Sheppard-Trujillo on June 27, 2014 while the left image shows the comet is not in this location a few days later (yellow arrow). The comet is not a point source like most stars and asteroids in the image but shows a fuzzy coma around the object that indicates it is outgassing material off its surface. (Credit, Scott Sheppard & Chad Trujillo)
Wednesday, August 06, 2014 

Scott Sheppard, along with Chad Trujillo of the Gemini Observatory in Hilo, Hawaii, discovered their first comet during observations at the Cerro Tololo Interamerican Observatory (CTIO) 4 meter telescope while looking for objects in the far outer reaches of the Solar System.   

The comet, named Sheppard-Trujillo after its discoverers, is one of the most distant comets ever discovered to show activity.  Sheppard-Trujillo is currently about 13 AU from the Sun, making it more distant from Earth than Saturn.  At this distance, water ice is too cold to efficiently sublimate off the surface of an object and thus the activity is likely caused by carbon monoxide or carbon dioxide sublimation, which is different than most comets that have their activity dominated by water ice sublimation.  

The orbit of the comet is in red,  the currrent location of the comet is the blue dot. The 8 major planets are shown by black circles.  One can see the comet's perihelion distance is the same as Jupiter's distance from the Sun showing their strong gravitational interactions. (Credit: Scott Sheppard & Chad Trujillo, DTM)

Sheppard-Trujillo also has an interesting orbit that will bring it in the vicinity of Jupiter at about 5 AU in 2021.  The low inclination of Sheppard-Trujillo suggests it likely came from the Kuiper Belt region just beyond Neptune.  The comet will likely gravitationally interact with Jupiter over the next few million years and eventually be ejected from the Solar System or collide with a planet or the Sun.

In March 2014, Sheppard and Trujillo published their discovery of a dwarf planet on the fringe of the solar system in NatureClick here to read more