Podcaster: Richard Drumm
Title: Space Scoop: Introducing DeeDee, the Distant Dwarf
Organization:365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1711/
Description: Space scoop, news for children
A new member joining the dwarf planet family very soon – an object called 2014 UZ 224 and nicknamed ‘DeeDee’, short for Distant Dwarf.
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Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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Transcript:
This is the 365 Days of Astronomy Podcast. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
Introducing DeeDee, the Distant Dwarf
You may remember that Pluto is now classed as something called a “Dwarf Planet”. As well as Pluto, there are four other dwarf planets in our Solar System: Ceres, Haumea, Makemake, and Eris.
Plus, there may be a new member joining the dwarf planet family very soon – an object called 2014 UZ 224 and nicknamed ‘DeeDee’, short for Distant Dwarf.
It was discovered by University of Michigan astronomer David Gerdes in 2016. His team used the 4 meter Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. The astronomers weren’t looking for trans-Neptunian objects. They were studying Dark Energy. Go figure!
Judging by how much heat is being reflected by it, it appears it is 635 kilometers across. So it’s well smaller than our Moon, and a little larger than Saturn’s Enceladus.
But what is a dwarf planet?
Dwarf planets are small bodies that orbit the Sun, like planets. Dwarf planets are spherical in shape, like planets.
In fact, the only difference between a dwarf planet and a normal planet is that dwarf planets haven’t “cleaned up” their neighborhood, removing stray asteroids and other small bits of space debris.
So, does DeeDee tick all these boxes?
Well, we’re not sure yet.
DeeDee is large enough to have enough gravity to pull itself into a spherical shape, but we haven’t yet proved that it has done so. If we get this proof, then it’s in the club!
DeeDee is currently out at 92 AU or 92 times farther from the Sun than the Earth, or almost three times farther than Pluto. At its farthest from the Sun, its aphelion, it’s 180 AU. At its closest it’s about 38 AU.
DeeDee’s the second most distant object ever discovered in our Solar System – the most distant is the dwarf planet Eris, which is currently 96.4 AU from the Sun.
The farthest point of its orbit, called its aphelion, is 97.6 AU, so Eris is close to its most distant part of its orbit.
When it gets closest to the Sun, at its perihelion, Eris is about 38 AU from the Sun, coincidentally about the same as DeeDee. For some of the time, Eris is closer to the Sun than Pluto. Pluto ranges from 29.7 to 49.3 AU and is currently 32.6AU.
But setting a different distance record we have minor planet 90377 Sedna. It’s currently about 86 AU from the Sun and is headed toward its closest approach to the Sun, where it’ll be 76 AU away.
But get this – it’ll get to around 937 AU when it gets to the most distant part of its orbit.
That’s a looooong way!
But back to DeeDee.
With its elliptical orbit, it takes DeeDee more than 1,100 years to complete one circuit around the Sun. And its current 92 AU distance also makes it incredibly difficult to see DeeDee, never mind study it in any detail. It’s 13 hours away at lightspeed!
But the ALMA radio telescope array in Chile’s Atacama desert has managed to collect an exciting new image of DeeDee. Do a Google Images search for 2014 UZ 224 and a red smudge will pop up.
The image reveals a small world that is about the same size as Oregon or Romania. Again, at this size, DeeDee is very likely spherical, which is one of the requirements to be called a dwarf planet.
When an object has enough material, gravity pulls it into a neat spherical shape. To be a full-fledged planet DeeDee would need to clear its orbit of debris & this has not likely been done.
More observations are needed before we can make the final verdict on DeeDee. Whether it’s a dwarf planet or just another trans-Neptunian object, Pluto has a new friend in the outer Solar System!
Hey, Here’s A Cool Fact:
Dwarf planets aren’t the only objects still hiding in our Solar System. Some scientists suspect that another planet, nicknamed ‘Planet 9’, is lurking on the edge of our Solar System!
In 2014 astronomers Chad Trujillo and Scott Sheppard proposed the existence of a trans-Neptunian planet.
Konstantin Batygin & Mike Brown of Caltech proposed that this planet would explain the orbital similarity of 6 large TNOs.
They also think that planet 9 might be the core of a gas giant that never got its gas in the gassy “nebular epoch” of the early solar system, and got ejected, most likely by Jupiter.
Whoa!
End of podcast:
365 Days of Astronomy
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