Universe Today
The
Kuiper Belt
has been an endless source of discoveries over the course of the past decade. Starting with the dwarf planet
Eris
, which was first observed by a Palomar Observatory survey led by Mike Brown in 2003, many interesting Kuiper Belt Objects (KBOs) have been discovered, some of which are comparable in size to Pluto.
And according to a new report from the
IAU Minor Planet Center
, yet another body has been discovered beyond the orbit of Pluto. Officially designated as
2014 UZ224
, this body is located about 14 billion km (90 AUs, or 8.5 billion miles) from the Sun. This dwarf planet is not only the latest member of the our Solar family, it is also the second-farthest body from our Sun with a stable orbit.
The discovery was made by David Gerdes, a professor of astrophysics at the University of Michigan, and various colleagues associated with at the
Dark Energy Survey
(DES) - a project which relies on the
Cerro Tololo Inter-American Observatory
in Chile. In the past, Gerdes' research has focused on the detection of dark energy and the expansion of the Universe.
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The DECam instrument, shown before it was inserted into the Blanco telescope at the Cerro Tololo Observatory. Credit: noao.edu
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Towards this end, DES has spent the past five years surveying roughly one-eighth of the sky using the Dark Energy Camera (DECam), a 570-Megapixel camera mounted on the
Victor M. Blanco telescope
at Cerro Tololo. This instrument was commissioned by the US. Dept of Energy to conduct surveys of distant galaxies, and Dr. Gerdes had a hand in creating.
Not surprisingly, this same technology has also allowed for discoveries to be made at the edge of the Solar System. Two years ago, this is precisely what Gerdes challenged a group of undergraduate students to do (as part of a summer project). These students examined images taken by DES between 2013-2016 for indications of moving objects. Since that time, the analysis team has grown to include senior scientists, postdocs, graduate and undergraduate students.
Whereas distant stars and galaxies would appear stationary in these images, distant TNOs showed up in different places over time - hence why are called "transients". As Dr. Gerdes explains in his
2014 UZ224 Fact Sheet
, which is available through his
University of Michigan homepage
:
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Images of 2014 UZ224, shown on three slides obtained by the DECam. Credit: David Gerdes/DES/University of Michigan
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This was a difficult process. In addition to needing thousands of computers at
Fermilab
to process the hundreds of terabytes of data, the team had to write special programs to do it. Gerdes and his colleagues also relied on help from Professors Masao Sako and Gary Bernstein of the University of Pennsylvania, who contributed the key breakthroughs that allowed them to perform difference imaging over the entire survey area.
In the end,
dozens of new Trans-Neptunian Objects
(TNOs) were discovered, one of which was 2014 UZ224. According to their observations, its diameter could be anywhere from 350 to 1200 km, and it takes 1,136 years to complete a single orbit of our Sun. For the sake of perspective, Pluto is 2370 km in diameter, and has an orbital period of
248
years.
Stephanie Hamilton, a graduate student at the University of Michigan, was personally involved with the project. Her role was to determine the size of 2014 UZ224, which was difficult from initial observations alone. As she told Universe Today via email:
[caption id="attachment_126970" align="aligncenter" width="580"]
Artistic rendering shows the distant view from theoretical Planet Nine back towards the sun. The planet is thought to be gaseous, similar to Uranus and Neptune. Hypothetical lightning lights up the night side. Credit: Caltech/R. Hurt (IPAC)
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But as with all things related to "dwarf planets", there has been some disagreement over this discovery. Given the dimensions of the object, there are some who question whether or not the label applies. But as Gerdes indicates on the Fact Sheet, this body fits most of the prerequisites:
Gerdes and his team expect to be busy, authoring the paper that will detail their findings, using the ALMA array to get more assessments of 2014 UZ224 size, and sifting through the data to look for more objects in the Kuiper Belt. This includes the fabled
Planet 9
, which astronomers have been seeking out for years.
Given its distance from the Sun, 2014 UZ224's orbit would not be influenced by the presence of Planet 9, and is therefore of no help. However, Gerdes is optimistic that the evidence of this massive body is there in the data. Given time, and a lot of data-processing, they just might find it! In the meantime, this newly discovered object is likely to be the focal point of a lot of fascinating research.
"It's an interesting object in its own right - distant objects like this are 'cosmic leftovers' from the primordial disk that gave birth to the solar system," writes Gerdes. "By studying them and learning more about their distribution, orbital characteristics, sizes, and surface properties, we can learn more about the processes that gave birth to the solar system and ultimately to us."
Further Reading: 2014 UZ224 Fact Sheet (University of Michigan)
