Planet X Larger Than Pluto? 561
nova_planitia writes "The Minor Planet mailing list is buzzing with the discovery by an amateur astronomer of a 17th magnitude object 51 astronomical units from the Sun, tentatively designated 2003 EL61. For those not versed in astronomical lingo, this is an object several times brighter than Pluto even though it is 25% farther out from the Sun (the orbit vizualised by JPL). This means that barring a strangely reflective surface, this object is larger than Pluto, possibly Mars-sized! The debate whether Pluto is a planet is likely to get rekindled by this discovery."
Broken Link, Naming Contest. (Score:4, Informative)
The link to the BBC story [bbc.co.uk] in the summary is broken.
A functioning link can be found here [bbc.co.uk].
So....the race is on to give this mysterious new planet a proper name! (Planet X is soooo Gen X...)
Please post your ideas below.
New Scientist Coverage (Score:4, Informative)
The New Scientist reports [newscientist.com]:
On Thursday a new planet-sized object was found orbiting the Sun at a distance of between 35-51 AU (at different points in its orbit) and an inclination of 28 degrees to the plane of the inner planets. By comparison Pluto orbits at an average distance of 39 AU and an inclination if 17 degrees. (1 Astronomical Unit = the distance between the earth and the sun) If the object has a reflectivity similar to that of other Kuiper-belt bodies, it is approximately twice the size of Pluto. Jose-Luis Ortiz and his colleagues at Spain's Sierra Nevada Observatory discovered the object while reviewing data from 2003. The International Astronomical Union's Minor Planet Center (MPC) in Cambridge, Massachusetts verified the obsevations and designated the object 2003 EL61.
Re:RTFA before you post an article to slashdot! (Score:2, Informative)
Re:Broken Link, Naming Contest. (Score:4, Informative)
Re:New Scientist Coverage (Score:2, Informative)
Here's the text of the message... (Score:5, Informative)
Hello MPML,
Jose Luis Ortiz of Sierra Nevada Observatory asked me to forward his message. Actually he sent it to MPML today but it looks as if he is moderated and so his message is delayed. As this is pretty urgent, to give anyone interested the chance to do science on it, I hope my message gets relayed faster!
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Hi there,
We found a very slowly moving object while carrying out a checking of some of our oldest images from the modest TNO survey that we started in 2002.
http://www.iaa.es/~ortiz/OSNTWeb/index.htm [www.iaa.es]
The object was very bright in our images (m_V~17.6!!) so we were able to precover it, and also recover it.
According to our best orbit fit and using regular assumptions on phase angle correction, the H value es around 0.3. Unfortunately we do not know the geometric albedo but if below 0.25 (which is the case of all TNOs for which an albedo has been measured except Pluto), the object would be larger than Pluto. However, it may well happen that this object is abnormally bright (with a very high albedo), like Pluto. So, depending on the albedo, this object might be sort of a Pluto's brother or Pluto's father...
This object is beyond Pluto and almost reachable by most amateurs, which is the reason why we write here!. It is observable right after sunset for a while at a reasonable elevation. Maybe some decent science can still come out of your observations.
Enjoy it!.
Our findings have been sent to the MPC, but the object has not received a provisional designation yet. Some ephemeris are given here:
Ephems (geocentric) [Date, RA, Dec, r, delta, elongation, mag]:
20050728.00000 13 21 50.208 +20 7 53.62 51.605 51.239 68.32 17.47
20050729.00000 13 21 51.856 +20 7 14.56 51.619 51.239 67.49 17.47
20050730.00000 13 21 53.576 +20 6 35.29 51.632 51.239 66.66 17.47
20050731.00000 13 21 55.369 +20 5 55.81 51.646 51.238 65.84 17.47
20050801.00000 13 21 57.233 +20 5 16.13 51.659 51.238 65.01 17.47
20050802.00000 13 21 59.169 +20 4 36.26 51.672 51.238 64.19 17.47
20050803.00000 13 22 1.176 +20 3 56.23 51.685 51.238 63.37 17.47
20050804.00000 13 22 3.253 +20 3 16.02 51.698 51.238 62.55 17.47
20050805.00000 13 22 5.401 +20 2 35.67 51.711 51.238 61.73 17.47
20050806.00000 13 22 7.619 +20 1 55.17 51.723 51.238 60.92 17.47
20050807.00000 13 22 9.906 +20 1 14.54 51.736 51.238 60.11 17.47
20050808.00000 13 22 12.261 +20 0 33.79 51.748 51.238 59.29 17.47
20050809.00000 13 22 14.685 +19 59 52.93 51.760 51.238 58.49 17.47
20050810.00000 13 22 17.176 +19 59 11.97 51.772 51.237 57.68 17.47
20050811.00000 13 22 19.734 +19 58 30.93 51.784 51.237 56.88 17.47
The orbital elements are:
OSNT11 Epoch 2005 July 29.0 TT = JDT 2453580.5
M 197.97485 (2000.0) P Q
n 0.00345428 Peri. 239.53682 +0.91285785 -0.07597426
a 43.3408541 Node 121.89008 +0.13526717 +0.98332108
e 0.1887862 Incl. 28.19395 -0.38521856 +0.16524998
P 285.33 H 0.2 G 0.15 U 2
--
Jose-Luis Ortiz
Instituto de Astrofísica de Andalucía, CSIC
P.O.Box 3004. 18080 Granada. Spain.
----------
Regards,
Jaime Nomen
620 OAM
Re:Broken Link, Naming Contest. (Score:2, Informative)
Re:Never noticed it before? (Score:5, Informative)
1) Although it is roughly the same distance from the Sun as Pluto the inclination is about 10 degrees off so they are actually not close at all.
2) Even if they were close, becuase the orbits are so slow at that distance (Pluto takes a few hundred years to orbit the sun) it would take a long time to notice pertubances in the orbit of Pluto.
3) Even though this planet is twice the size of Pluto, it is still really really small. Pluto is smaller then our moon so at the distances we are talking here the interactions are going to be so small as to be completely unnoticable with our current technology.
Re:Oh great. (Score:2, Informative)
Re:New Scientist Coverage (Score:3, Informative)
Re:Never noticed it before? (Score:2, Informative)
1. space is HUGE and you have the needle in the haystack adage -- if you don't look in the right place, at the right time...
it is not on the same plane as Pluto (so it's not following like cars on the road). Add the fact that its orbit is extremely long, you're right back to needle and haystack. How often do Pluto and the object get close enough to peturb each other?
2. Just because it is larger than Pluto doesn't make it easier to see -- it is a VERY long distance from the sun to the object, so there isn't a lot of light to reflect (not quite the best analogy but, can you see a candle reflecting light from 20 miles?)
3. Astronomers' equipment gather a tremendous amount of info every year, and it takes time to review the material. Was that faint spot a speck of dust on the lens? a computer glitch? they have to track the object to note its motion, size, etc.
Vulcan was the planet inside Mercury's orbit (Score:5, Informative)
Not Planet X (Score:3, Informative)
Re:Doesn't add up (Score:4, Informative)
You are thinking of the absolute magnitude. Typically, absolute mangitude is refered to as such while the visual magnitude is refered to as magnitude.
The reason Pluto was considered a planet (Score:4, Informative)
Pluto was once thought to be much more massive than it is currently known to be. When I was in high school, prevailing theories had it as being slightly larger than Mercury. Furthermore, it was first discovered due to its supposed perturbation on the planet Uranus (those perturbations were, in fact, due to incorrect calculations, IIRC). Additionally, we had very little information on other objects of similar ilk. So, why wouldn't it have been considered a planet?
The flip side of the question is, "should we change its status now?" I don't really care much, but I don't see why its so important whether its a planet or a KBO, from a labeling point of view.
Some might argue that it makes teaching about the Solar System easier, but I think the exceptions can help to make the system more interesting, and, hence, easier to learn about.
Well, in that case, here's my journal entry on it! (Score:3, Informative)
Essentially, European astronomers have found something they call 2003 EL61 [www.iaa.es] and what American astronomers call K40506A [aas.org].
There are questions on how reflective the object is, which means we don't have that much information on how big it is or how far away it is. The guesses by astronomers, at this point, are pretty speculative, according to the BBC [bbc.co.uk], which is tracking this breaking story.
NASA [nasa.gov] has published a wild guess as to the orbit, in Java.
The other known super-large (1000Km or bigger) Kuiper Belt objects are:
Re:Water? (Score:4, Informative)
There could still be free-flowing water under the ice with life swimming around in it.
Highly unlikely...scientists believe that there may be liquid water under the ice of Europa (I assume that's the parallel you're attempting to draw here) because of the heating caused by the tidal action of Jupiter's gravity (don't take my word for it...here's an informative link [resa.net]).
As far out from the Sun as this planet is, it is certain that it recieves an insufficient supply of either radiation or tidal friction to warm water ice to the melting point.
Re:Broken Link, Naming Contest. (Score:4, Informative)
Lord John Whorfin: Where are we going?
Red Lectroids: Planet Ten!
Lord John Whorfin: When?
Red Lectroids: Real soon!!
Perhaps a New King of the Kuiper Belt (Score:5, Informative)
What we have here is one that could be larger than Pluto. This is not unexpected, but has been predicted ever since we started discovering KBOs in serious numbers. There is always a distribution of sizes, and Pluto lies near the upper end, but it is unlikely that it is the largest, and even less likely that it would be distinctly larger than the rest of the population.
To call Pluto a planet is to create a category of "ice planets" which contains only one object. That is scientifically silly. To call it a Kuiper Belt Object fits it in with a family of other objects whose characteristics in composition, orbit size, orbit shape, orbit inclination, companions, etc are shared amongst the group. That is a scientific classification.
The solar system does not contain "the Sun and
9 planets" as so many of us incorrectly learned. Rather, it contains 6 families: a star, the rocky planets, the asteroid belt, the gas giant planets, the Kuiper belt, and the Oort cloud. Each of these families shares common characteristics that are the basis for this classification. Pluto, and this new discovery,
fit squarely in the Kuiper belt.
Now for the truth about planets. The IAU, which
governs these things, has no official definition of what constitutes a planet. There is a reasonable upper limit in mass (i.e., not so larger as to create fusion at it core), but there is no lower limit. Most astronomers would say that a reasonable idea would be large enough for gravity to make it spherical (or close to, like Earth). However, then other KBOs and asteroids qualify as planets. You simply can't come up with a rigorous definition that includes Pluto and excludes the others unless you work customize your definition in a manner that is not scientific.
This will not be the last big KBO. There will be several more. These are exciting times as we discover more and more about our own backyard.
More info at Space.com (Score:4, Informative)
Rb
Re:New Scientist Coverage (Score:2, Informative)
Actually, its fainter than Pluto (Score:3, Informative)
Re:Pluto is no planet (Score:3, Informative)
It's not just the orbit of the inner planets (which would be Mercury, Venus, Earth and Mars) on that plane. All planets except Pluto fit on there.
The Sun rotates. Furthermore, it rotates along the same plane as the planets' orbits. (Again, you can confirm this yourself if you have Celestia. Just go to the Sun, back up a bit, make sure the orbits are turned on and speed up time a bit.)
The theory I read in The Cartoon History of the Universe (great book) was that as the gases condensed to form the Sun they began to spin faster and faster. This scattered out debris that would orbit around the Sun along the same plane. It is that debris which condensed to form what I consider to be planets.
Second, what exactly is a "planet"?
Good question. I wonder if there is some exact set of rules that decides this. Even though it may not be the technical definition, I like the idea of the offspring of the Sun being the de facto planets in our Solar System.
Re:Abbot/Costello (Score:3, Informative)
I've had way too much coffee this morning.
-l
Re:Pioneer (Score:4, Informative)
Both Pioneer Spacecraft (as well as Voyager) measure the anomaly, and they are moving away from the Sun in different directions. A distant object has been ruled out as a potential source of the effect, since to produce a slowing of all the spacecraft you need a force acting towards the sun. Whatever is causing them to slow down, it's not a solar system body too far out for us to see.
Re:Pluto is a planet? (Score:3, Informative)
It is true that Jupiter gives off more energy than it receives from the sun. BUT of the energy emitted is not from fusion.
Jupiter is too small to produce a core temperature high enough to create fusion. It takes about 3 million degrees to start the fusion of hydrogen.
That means Jupiter is definately a planet by my definitions.
Re:More info at Space.com (Score:1, Informative)
What was interesting to me is that the discoverer of Sedna [caltech.edu], Mike Brown of Caltech, has been monitoring this object for some time, and was just about to make an announcement about it before this announcement by the Ortiz group was made. Apparently the Brown group was only waiting for some data from the Spitzer Space Telescope, which arrived last week. Based on the Space.com article, it appears the Brown group knows a lot more about this object than anyone else--including the fact that it has a moon. There's a very nice image of the planet and its moon with the Space.com article.
Re:More info at Space.com (Score:1, Informative)
Re:Name for it: (Score:4, Informative)
joking aside, Lesbos was a Greek island and had nothing to do with Roman gods (which our planets are named after). The island got its reputation from Sappho, the poet (also the synonym sapphic is derived from her, though rare to see these days).
Incidentally, Sappho was married and if she did munch the rug it would make her bisexual, which makes the association incorrect, anyway.
Now that I've shot that option down, I need to catch the first shuttle to Bacchus
Not Planet X, no demotion (Score:3, Informative)
Planet X was thought to be a very large planet, responsible for causing apparent perturbations we were seeing in the orbit of Uranus and Neptune. When Voyager II flew by these planets and got refined measurements of their masses, the discrepancies went away. We now know that the revised data shows no perturbations, putting severe limits on very large objects to very great distances. That is, there is no Planet X, and there never was.
There are likely all sorts of Pluto-sized objects out there, though. So finding another one is not surprising. There's nothing special about the mass of Pluto, and so some Kuiperoids will be around the same mass, and some will be more (though probably not too many). Thus, this discovery is nothing very surprising. You'd expect to find Kuiperoids more massive than Pluto out there.
As for reigniting the "controversy" about Pluto's planetary status, probably not. There's really not much controversy here. The IAU does not have and never has had an objective definition of the word planet that Pluto succeeds or fails in meeting the criteria for. A planet is literally what we point to and say, "That's a planet." The terms are made up by us, after all; do you think Pluto cares what it's called? Do you think that somehow further enhances the study of it, knowing that it's in this classification bin but not this one?
There have been a few serious astronomers suggesting conferring dual classification -- as both a planet and an asteroid/Kuiperoid -- to Pluto. The official proposal was never about demotion. Talk at length about removing planetary status from Pluto has largely been taking place in the popular press and by amateurs. Most actual astronomers don't care, because it doesn't matter what name you give something.
Another one... (Score:5, Informative)
http://cfa-www.harvard.edu/mpec/K05/K05O41.html [harvard.edu]
http://neo.jpl.nasa.gov/orbits/2003ub313.html [nasa.gov]
Re:Here's the text of the message... (Score:3, Informative)
Even more interesting... (Score:5, Informative)
However, there's an even more interesting thing that Mike Brown has on his page, called 2003 UB313 [caltech.edu] (a.k.a. "Lila").
Re:Perhaps a New King of the Kuiper Belt (Score:3, Informative)
Re:Pioneer (Score:2, Informative)
IIRC, The Voyagers were unable to measure it because of the stabilization technology they use.
Re:Even more interesting... (Score:2, Informative)
In the event, only 2003 UB313 ("Lila") is larger than Pluto and is the first of the 700-odd Kuiper-Belt Objects (KBOs) discoevered since 1973 to have that honor, so it is presently the only real candidate for Planet X. However, its orbital inclination at 44 degrees makes it a very odd planet in comparison to the other 9.