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Planet X Larger Than Pluto?
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."
From my inexplicably rejected story submitted hours ago:
The New Scientist reports:
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.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Clearly it should be named Rupert
It came in about seven o'clock last night...
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
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.
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Regards,
Jaime Nomen
620 OAM
There are several reasons why this planet can't be detected gravitationally.
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.
Save the whales... Collect the whole set.
Before Einstein explained the precession of Mercury's perihelion, many scientists believed there was a planet Vulcan inside Mercury's orbit. Some even "spotted" it. (For the "Some" link, search on "Vulcan".)
Ben Hocking
Need a professional organizer?
The magnitude (really, the visual magnitude) is a measure of how bright the object appears in the sky, not the absolute brightness of the object. Think of it this way. The Sun has a magnitude of -26.7. Vega has a magnitude of 0. Vega is a much brighter star than the sun, but because of the differing distances from the Earth (and therefore, the observer) Vega appears much dimmer than the Sun.
You are thinking of the absolute magnitude. Typically, absolute mangitude is refered to as such while the visual magnitude is refered to as magnitude.
Amongst professional astronomers (which includes me), Pluto is generally not considered a planet. It is the largest member of the Kuiper Belt. It is historical accident that Pluto was discovered almost 50 years before the second Kuiper Belt object, Charon, in 1978. The third KBO was found in 1993. Since then, over 700 other KBOs have been found, several of which rival Pluto in size.
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.
In a word - No.
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.
-- IANAL, BIPOOTV
Just when you thought that this couldn't be bigger news, Ron Baalke at JPL has pointed out that another object, 2003 UB313, resides at 96 AU and has a diameter from 4400 km to 9900 km, assuming its albedo is between 0.05 and 0.25. Though the inclination is a bit weird (44 degrees), this may be considered planet-sized.
http://cfa-www.harvard.edu/mpec/K05/K05O41.html
http://neo.jpl.nasa.gov/orbits/2003ub313.html
However, there's an even more interesting thing that Mike Brown has on his page, called 2003 UB313 (a.k.a. "Lila").
Show me on the doll where his noodly appendage touched you.