"Snow White" -- Possibly the 3rd Largest Dwarf Planet

A previously known body discovered in 2007 -- officially known as "2007 OR10", but unofficially nicknamed "Snow White" -- may be larger than previously thought. it was previously believed that 2007 OR10 was the 7th largest of the known dwarf planets, but a new study suggests that it might be the third largest, smaller than only Pluto and Eris.

2007 OR10 is the largest dwarf planet without an official name, as "Snow White" is just a temporary placeholder name (just like Eris [before it was officially named "Eris"] was unofficially nicknamed by it's discoverer as "Xena", named after the TV character and warrior princess).

Mysterious Dwarf Planet 'Snow White' Much Bigger Than Thought: Study

A faraway object nicknamed "Snow White" is considerably larger than scientists had thought, and is in fact the third-largest dwarf planet in the solar system, a new study suggests.

Snow White is about 955 miles (1,535 kilometers) in diameter rather than 795 miles (1,280 km) wide as previously believed, according to the new study. That makes it the largest still-unnamed object in our solar system, NASA officials said. (The dwarf planet has not yet been formally named and currently goes by the placeholder designation 2007 OR10.)...

...If the new measurement is accurate, the only known dwarf planets bigger than Snow White are Pluto and Eris, which are 1,475 miles (2,374 km) and 1,445 miles (2,236 km) across, respectively.

Caption from Article:
Artist's illustration of 2007 OR10, nicknamed "Snow White." Astronomers suspect that its reddish color is due to the presence of irradiated methane.
Credit: NASA

The size uncertainty is a result of not knowing the color and absolute brightness of the object. For example, if it had a darker surface, the relative brightness of the object as seen from Earth would indicate that it was larger than it was if it had a brighter surface.

However, the discoverer of 2007 OR10 / "Snow White", Mike Brown (the Pluto-Killer Mike Brown * [see note below]) isn't quite ready to declare that the size upgrade is accurate.

One of the people who discovered Snow White back in 2007, California Institute of Technology astronomer Mike Brown, urged people to take this uncertainty into account before giving the dwarf planet the third-place trophy.

"Be a little skeptical that 2007 OR10 is the third-largest dwarf planet, please. It has the least well measured size. Could easily be [smaller than] Makemake," Brown said via his Twitter account, @plutokiller, on Wednesday (May 11).

* Note: Mike Brown is referred to as "Pluto-Killer" (Mike Brown even refers to himself as this) because it was his discovery of the Pluto-like objects Eris and Sedna back in the early 2000s that prompted the International Astronomical Union in 2006 to create the new category of "Dwarf Planet" to describe bodies such as Eris, Sedna, and Pluto -- which demoted Pluto out of the ranks of being the ninth major planet.

For more information about 2007 OR10 / "Snow White", refer to this three-part blog written by Mike Brown back in 2011. This blog presents an interesting history of the investigation of the dwarf planet.

Mike Brown's Planets (Blog) - The Redemption of "Snow White", Pt 1
Mike Brown's Planets (Blog) - The Redemption of "Snow White", Pt 2
Mike Brown's Planets (Blog) - The Redemption of "Snow White", Pt 3

So maybe this is the 3rd largest dwarf planet, or as Mike Brown cautions, it may not be. It sounds as if a little more research needs to be done in order to settle it.

What interesting times, astronomy wise, we live in.

Thanks for the post

A bit off topic, but this is a fascinating star tickle on mike brown and the pluto debate.

www.theguardian.com...

a reply to: Soylent Green Is People

The discovery of more and more dwarf planets makes me wonder if our solar system is still in the formation period. We have classified 4 so far in the kuiper belt, but maybe they are in the slow process of planetary accretion. There are lots of speculated dwarf planets in the kuiper belt

It is possible that there are another 40 known objects in the solar system that could be rightly classified as dwarf planets. Estimates are that up to 200 dwarf planets may be found when the entire region known as the Kuiper belt is explored

link

We definitely won't experience it in our lifetime, nor in the next thousand generations. But maybe there will one day be another 9th planet. Well, 10th planet, Pluto will always be number nine to me.

originally posted by: 3danimator2014
A bit off topic, but this is a fascinating star tickle on mike brown and the pluto debate.

www.theguardian.com...

So...dwarf planet now haha... I guess that means Pluto is still the ninth planet.. GOOD!!!

Anyway @plutokiller is a childish name, we shouldn't let anyone who goes by kiddie names deciding what's a planet....

originally posted by: imitator

originally posted by: 3danimator2014
A bit off topic, but this is a fascinating star tickle on mike brown and the pluto debate.

www.theguardian.com...

So...dwarf planet now haha... I guess that means Pluto is still the ninth planet.. GOOD!!!

I'm not sure what you mean by "now".

At the same time Pluto was demoted from being a major planet, it was assigned the newly created designation of "Dwarf Planet". This all happen 10 years ago. That new designation of "dwarf planet" was created especially for Pluto and the (at the time) recently discovered Pluto-like bodies of Eris, Sedna, Quaoar, and the like.

So as soon as it was no longer a major planet, it was immediately redesignated a dwarf planet.

Anyway @plutokiller is a childish name, we shouldn't let anyone who goes by kiddie names deciding what's a planet....

Mike Brown was not the person who decided what was and what wasn't a planet -- although he does have an opinion on the matter. In fact, there was not one single person who made the decision to create the new designation of dwarf planet for Pluto. Rather, it was the International Astronomical Union (IAU), which is made up of many voting members.


As for the nickname given to Mike Brown of "Planet Killer", it may be whimsical, but there's nothing wrong with a scientist with a little whimsy in him. If you ever heard Mike Brown speak or read his writings, he thankfully is not so full of himself or so constantly serious or dour that he doesn't have time for a little fun.

I mean, there's nothing wrong with a scientist having a sense of humor. Some of the most respected scientists ever had or have great senses of humor. Stephen Hawking is supposedly a very playful man and quite the kidder (although his disability may hide that fact), and Albert Einstein was known to enjoy his fun.

originally posted by: Vector99
a reply to: Soylent Green Is People

The discovery of more and more dwarf planets makes me wonder if our solar system is still in the formation period. We have classified 4 so far in the kuiper belt, but maybe they are in the slow process of planetary accretion. There are lots of speculated dwarf planets in the kuiper belt
...

That's one reason why the new designation of "dwarf planet" was created in the first place, and why Pluto was included.

Astronomers for decades (actually ever since Pluto was discovered) debated if Pluto should even be considered the ninth planet, given not only its small size, but its extreme orbit compared to the other 8 planets -- i.e., Pluto orbit the Sun like no other planet, not only is the orbit tilted in a very extreme manner, but the orbit also carries it INSIDE the orbit of Neptune for a time.

So then came the discovery of Eris, Sedna, Quaoar, Haumea, Makemake, etc. that were objects very similar to Pluto (especially Eris, which is about as large as Pluto). Along with that discovery came the implication that perhaps hundreds similar Pluto-like objects exst in the Kuiper belt....

...and if Pluto was the ninth planet, then Eris would be the 10th, and Sedna would be the 11th, and the other couple of hundred similar bodies that might exist would ALL be planets -- until our solar system had hundreds of things we call planets.

So planets were broken up into two types -- Major Planets (the 8 planets ending with Neptune) and Dwarf planets, such as Eris, Pluto, Sedna and such.

The exact definitions of each as defined by the International Astronomical Union in 2006 is as follows:

Planet -- A celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

Dwarf Planet -- a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

a reply to: Soylent Green Is People

Oh I know of the classification changes and why. Doesn't make me think of Pluto any less though hehe

Though what do you think about the possibility that over the next few million years a bunch of these dwarf planets will cross paths becoming bigger and bigger?

I wonder if it's even a theory looked into honestly.

originally posted by: Vector99
a reply to: Soylent Green Is People

Oh I know of the classification changes and why. Doesn't make me think of Pluto any less though hehe

Though what do you think about the possibility that over the next few million years a bunch of these dwarf planets will cross paths becoming bigger and bigger?

I wonder if it's even a theory looked into honestly.

Nope, the objects past Neptune are commonly considered as "leftovers" from the formation of the Solar System. Out there, there's just not enough material concentration for planets to grow. There are many Kuiper belt objects, true, but Kuiper belt is very, very big.

originally posted by: Soylent Green Is People

originally posted by: Vector99
a reply to: Soylent Green Is People

The discovery of more and more dwarf planets makes me wonder if our solar system is still in the formation period. We have classified 4 so far in the kuiper belt, but maybe they are in the slow process of planetary accretion. There are lots of speculated dwarf planets in the kuiper belt
...

That's one reason why the new designation of "dwarf planet" was created in the first place, and why Pluto was included.

Astronomers for decades (actually ever since Pluto was discovered) debated if Pluto should even be considered the ninth planet, given not only its small size, but its extreme orbit compared to the other 8 planets -- i.e., Pluto orbit the Sun like no other planet, not only is the orbit tilted in a very extreme manner, but the orbit also carries it INSIDE the orbit of Neptune for a time.

So then came the discovery of Eris, Sedna, Quaoar, Haumea, Makemake, etc. that were objects very similar to Pluto (especially Eris, which is about as large as Pluto). Along with that discovery came the implication that perhaps hundreds similar Pluto-like objects exst in the Kuiper belt....

...and if Pluto was the ninth planet, then Eris would be the 10th, and Sedna would be the 11th, and the other couple of hundred similar bodies that might exist would ALL be planets -- until our solar system had hundreds of things we call planets.

So planets were broken up into two types -- Major Planets (the 8 planets ending with Neptune) and Dwarf planets, such as Eris, Pluto, Sedna and such.

The exact definitions of each as defined by the International Astronomical Union in 2006 is as follows:

Planet -- A celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

Dwarf Planet -- a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

Interesting thread.

I wonder how they explain Haumea since it is not nearly round, as a planet.

originally posted by: burgerbuddy
I wonder how they explain Haumea since it is not nearly round, as a planet.

Well, "round" is just a layman term. Astronomers use the term hydrostatic equilibrium, which is when an object's gravity balances out its pressure gradient force. Haumea, although thought to be elliptical in shape due to very rapid spinning, is also though to have achieved hydrostatic equilibrium.