Planet No.10?

New TNO discovered by Brown et al called
2003 UB313. It's diameter ranges from 4400 km to 9900 km, assuming its
albedo is between 0.05 and 0.25. This might qualify as
a new planet. It has an incredible high inclination though of 44 degrees.

This discovery is in addition to the previous one with the designation 2003 EL61 Ortiz et al.

Eamonn A

I believe this recent discovery is not a planet as we would know it.
if Pluto is a planet, then other round objects nearly as large as Pluto ought to be called planets. So therefore, 2003 UB313 would perhaps be a planet, but it would have to get in line behind the other near Pluto sized objects like Sedna, Quaoar and 2004DW.

I would not call it the 10th planet because Pluto and other small objects beyond Neptune should be called, at best, "Kuiper Belt planets."

At present there is no definition for a for 'planet'. The very definition of what constitutes a planet is currently being debated by a working group of the International Astronomical Union. And in fact the debate may go on a while as astronomers find more objects like today’s discovery.

There has never been a definition for the word "planet," because the nine we knew are historically accepted.

Other astronomers had predicted in the early 1990s that there would be 1,000 Plutos out there and there should be Mars-sized worlds and even possibly other worlds as large as Earth.

So we have a lot of undiscovered objects to find in the outer solar system yet. We’re only just starting to find the first few in the last 2 years

Apparently my PhD research on EKBOs with the PSSRI in the UK has the 10th planet beyond the Edgeworth Kuiper Belt as a piggy back project. This hypothetical planet is fundamentally different as to how it got there as compared to the evolution of the Kuiper Belt. There are indications that it should be there based on the aphelia distances of long period comets showing excess at specific distance from the Sun. The object could be the size of Jupiter. This would definitely be the 10th planet as it would be obvious.

Eamonn A

Eamon, there is going to be one hell of a debate on this subject, my own personal opinion is that many, many more objects of this type will be found over the next decade or so. I think that so many of these will be found, that announcements such as this will become routine, the term used to describe them as a 'planet' will become somewhat diluted, and agreed, will be termed KBO's and such, I think the IAU would have no other choice but to call them that. An orbital inclination of 44 degrees is by no means in line with the 'big 9' so these objects have to be treated differently I think.

Now an object the size of earth or upwards could certainly qualify as a planet,
we might just detect one of these yet! Then we could think about the number 10.

It's great we live still in an age of discovery

:!:

Keep up the PhD work, and of course,
Clear Skies!
Keith..

Out of interest has anyone seen a reference to the magnitude of this object?

I'm sure its well beyond my scopes range, but I am wondering about the kind of telescopes that would be required for an automated search for similar objects.

Cheers,
~Al

Albert,

Here are positions and magnitudes for both 2003 UB313 "Tenth Planet" discovered by Brown et al.using the 1.2m telescope (Mt Palomar) at mag 18.4 and 2003 EL61 discovered by Ortiz et al with a 0.36 telescope
in Spain.

2003 UB313:


2003 10 21.26747 01 36 13.82 -06 07 15.3 18.8 R EO041644
2003 10 21.33840 01 36 13.67 -06 07 16.1 18.8 R EO041644
2003 10 21.40306 01 36 13.53 -06 07 16.8 18.8 R EO041644

2005 01 08.06424 01 34 44.08 -05 51 58.2 18.4 R EO041807
2005 01 09.07007 01 34 43.86 -05 51 47.3 18.4 R EO041807
2005 01 10.08784 01 34 43.69 -05 51 36.0 18.4 R EO041807


Ephemeris:
Date TT R. A. (2000) Decl. Delta r Elong. Phase V
2005 07 29 01 39.38 -05 19.3
96.681 96.939 104.4 0.6 18.9
2005 08 08 01 39.30 -05 21.0 96.526 96.937 113.7 0.5 18.9
2005 08 18 01 39.16 -05 22.9 96.382 96.936 122.9 0.5 18.9
2005 08 28 01 38.97 -05 25.0 96.254 96.934 132.1 0.4 18.8
2005 09 07 01 38.72 -05 27.3 96.146 96.933 141.2 0.4 18.8

2003 EL61


2003 03 09.01612 13 19 56.32 +20 40 29.8 17.7 V EO036J86
2003 03 10.01530 13 19 53.05 +20 41 06.4 17.6 V EO036J86

Eamonn A

Regarding your other question to carry out a survey for the brightest TNOs. You'll need the very minimum use of an LX200 12 inch telescope, that will enable you to capture images at 19 mag. A C14 would be a bit better where you can achieve 19.5 mag. A 16 inch would achieve a bit better at 20 mag. If you have a high QE CCD camera you would have less time tracking.

BTW Ortiz and team (whom are professionals used a 14inch telescope to capture 2003 EL61 at 17.4 mag.

Best to use a wide FOV, therefore a telecompressor at around X5. This will enable you to achieve approximately f/5 with some of the instruments above. Ortiz used f/6

However, these EKBOs that they have discovered are exceptionally bright, most EKBOs are around 22 nd mag. which require the use of telescopes of at least 30 inches for these surveys with good tracking and high QE CCD cameras.

If you are interested and want to do a survey I may be able to help you. More details by e-mail.

Eamonn