Farthest Solar System Object - Sedna?

[TheThorn]

Nasa Schedules News Conference About Unusual Solar Object

Well, they've got my attention. They say they're going to present the discovery of the most distant object ever seen in the solar system, on Monday at 1 PM EST.

I wonder what it is. From the hype, it doesn't sound like just another KBO.

[damienpaul]

a new planet perhaps??? I will keep my eye on the broadcasts, or perhaps Fraser could report on it.

[TheThorn]

I'll admit it. The first thing I thougt of was that guy who was in here a couple of months back claiming he had evidence that there was a brown dwarf out there beyond the Kuiper Belt. What was his handle? I can't seem to find the threads he was involved in.

[antoniseb]

The announcement implies it was discovered in some Spitzer images. So the object is something that must be fairly easily found in the mid-infrared. A planet or brown dwarf might qualify.

I had thought it was interesting that the kuiper belt had such a hard apparent outer boundry. That sort of suggests a planet. A brown dwarf seems too extraordinary. I'm guessing planet.

Either way, I can hardly wait!

[damienpaul]

So what are the bets? Who wants to wager on Brown Dwarf? Who wants to wager on Planet? who wants to suggest another wager?

[TheThorn]

There was some speculation in YahooGroups MPML (Minor Plante Mailing List) that it might be 2004 DW - a very distant KBO that was discovered recently apparently by the same people making this announcement. Then this post came in from Jim Scotti who apparently is in the know:

"Actually, the object that is to be announced is most decidedly not 2004 DW,
but another object on a very different orbit. Dr. Brown gave a talk here at
LPL a couple weeks ago where he showed us images of this new object (as well
as telling us about the discovery of 2004 DW) and described briefly what he
knew of it at the time and of some of the implications of its existance.
Trust me, it is a unique object in our inventory, nothing like any other
object we've ever seen, but probably not the only one of its kind."

Let's speculate. We'll find out soon enough.

"On a very different orbit" would imply not a KBO, or at least on an orbit that is different in some way than the other KBO's and scattered disk objects.

"Unique in our inventory" is another hint, which would make one think of a brown dwarf, or something other than just a gas giant or big, distant KBO or whatever.

Maybe out that far a gas giant" would actually be an "ice giant". That would be unique.

"The importance of it's existence" kind of implies that its very existence explains some other things (like the hard outer edge of the Kuiper Belt that antoniseb mentioned, or the apparent clustering of the aphelia of long period comets.

But then "probably not the only one of its kind" raises all sorts of other questions. If they'd found a brown dwarf or gas giant in the zone between the Kuiper Belt and the Oort cloud, what would make them speculate that more would "probably" exist?

The only thing I'm willing to bet on at this point is that whatever the announcement is, it's in The Universe Today on Tuesday

[DippyHippy]

I was wondering if this might make it onto UT before Monday...

A few of us are on the emailing list for press releases and this one came through to me on Friday night, at about 5:20pm GMT. Basically, the email read exactly the same as the release linked to above.

In the three years I've been on the list, I've never seen anything announced in this way...

I don't think it's a KBO because when the largest KBO was recently announced, they did so in the normal fashion. No big fuss over that.

I don't think it's anything to do with the Oort cloud either, for the same reason - they wouldn't make this much fuss over it.

As discussed in emails with others, although I'd put my money on a brown dwarf or massive gas giant, a brown dwarf should have been detected already and a gas giant that far out would defy current planetary formation theories. *But* when they found gas giants close to other stars, that defied planetary formation theories too.

I don't think it's anything extra-terrestrial because Bush would make the announcement, I think. (Not that he has any right to, but that's just the way it would happen, I believe)

Whatever it is, I'll bet good money it's gonna be on the evening news...

[DippyHippy]

BTW I'm just moving this to the Other Stories section since I think it'll get more attention there

[Planetwatcher]

I'm thinking that this will be a KBO which is larger and/or farther then Pluto.
While other large KBO's were reported in the normal fashion, none were nearly as large as Pluto, and not many of them are significantly farther.
By significantly farther, I'm speaking in terms of either Bode's Law, or a body more then twice the distance of Pluto from the Sun.

As discussed in emails with others, although I'd put my money on a brown dwarf or massive gas giant,

Other then this one point, I tend to aggree with Dippy Hippy.

[Faulkner]

Maybe it's a black hole on a collision course with Earth!?

[antoniseb]

Originally posted by DippyHippy@Mar 14 2004, 05:09 AM
a brown dwarf should have been detected already and a gas giant that far out would defy current planetary formation theories.

If the object is a brown dwarf [roughly 10-85 jupiter masses] it could have remained un-noticed if it:
- formed billions of years ago [and so has cooled]
- it has no large moons reheating it's atmosphere with tides
- is located thousands of AU away from the sun [and so does not detectably affect the orbits of Neptune and other planets]
- was going through part of its orbit that is against the Milky Way as we see it.

I am speculating that it is a captured object. That is, something that did not form with the sun, but was in a more elliptical galactic orbit, and got accelerated by the sun's gravity into co-orbiting with us.

[GOURDHEAD]

:unsure: Maybe a binary binary or even larger grouping of near Pluto sized objects.

Unless its in or beyond the Oort cloud, anythning equal to or greater than Jupiter should affect the orbits of some of the outer planets in a manner subject to current observational technology. But then Pluto has only been observed over less than a third of its period. :unsure:

[TheThorn]

Here's something that I'm betting is related, from Spaceref.com's Daily Hubble Status Report. for Mar. 11 (at the bottom of the page)

"SIGNIFICANT EVENTS:

Loads for SA075O02_F1 were signed off @ 072/0800z. SA075O02 supercedes SA075O01, and includes the additional "Director's Discretionary Target" for proposal # 10041 "Characterization of a Planetary-sized Body in the Inner Oort Cloud".

They retargeted the Hubble at the last minute to take pictures of it.

OK, Damienpaul, I'm ready to bet now. I'm betting on a planetary sized body in the Inner Oort Cloud.

I'll also bet that after this is announced, there will be another debate on the status of Pluto - Planet or Kuiper Belt Object.

[DippyHippy]

Just a quick point... Faulkner, if it were a black hole, I think you'd be feeling the effects by now, even at this distance.

I think the TheThorn's right... that HST report sounds connected... but how do you define "planetary sized"? As big as / bigger than Pluto?

[antoniseb]

Some more thoughts on the Brown dwarf idea:

Visual Brightness
Lets assume that there is a brown dwarf at some distance from the sun. Assume that it has the surface area of Jupiter [a conservative guess, brown dwarfs are probably a little larger than that]. Also assume that it reflects light with about the same reflectivity Jupiter has. Planet brightness goes down according to the 4th power of distance. If the Brown dwarf were 1000 times as far away as Jupiter, it would be 1e12 times dimmer than Jupiter, making it 30 magnitudes dimmer, that is magnitude 28. Note that it it were 10,000 AU, it would just barely have appeared as a gray streak on the Hubble Ultra Deep Field survey [if by incredible luck it were in the field]. Of course the Oort cloud probably goes out ten times that far. Who knows where this thing could be?

Note that in the Infrared, Jupiter gives off more light than it reflects because it is slowly collapsing, and radiating away the heat that holds it up. A Brown Dwarf would be doing the same thing.

Gravitational Influence on Inner Planets
The acceleration it would have on Neptune would be (M[bd]*G / R*R)
If we assume [for example] R= 7,000 AU = 1e14 meters, and M[bd] = 1e30 Kg [upper end of the range], a[max] = 100G which is about 1e-8 meters per second per second.

At most, this would affect Neptune's orbital position by about 1000 kilometers over the course of a year. If it were a light-weight brown dwarf at four times that distance, the displacement would be 10 Km over a year.

Conclusion
A brown dwarf could be out there and have remained undetected.

[Manchurian Taikonaut]

10th Planet for the SOL system
:huh:
...some news

http://www.theaustralian.news.com.au/commo...5E29098,00.html

planet SEDNA orbits at 67 AU from the Sun

[DippyHippy]

Woohoo!!! Thanks for the link

And the winner for the first correct guess is.... *drum roll* Antoniseb!

[burmese]

See:
http://www.theaustralian.news.com.au/print...8968352,00.html

and

http://www.nasa.gov/home/hqnews/2004/mar/H...lar_object.html

[antoniseb]

This is cool. Somehow, I am happy that it isn't some distant Brown Dwarf. I don't know why, but somehow I don't seem to like big surprises in our own solar system.

It will be interesting to know the orbital inclination and eccentrity.

It will not be interesting to hear the symantic debate about whether it's a planet or not.

[DippyHippy]

I'm going to merge this with the topic in Other Stories because someone has already posted the link and the subject is being discussed there.

[DippyHippy]

Oh boy... I wish I could post what I've just heard but I gave my word... but trust me, this is fascinating... it's a lot more mysterious than the Aussie article makes out... this is the sort of discovery that re-opens a lot of debates about KBO's, the Oort Cloud, Pluto and all the planetary-formation theories....

[DippyHippy]

The BBC have now broken the story too... (about an hour ago)

http://news.bbc.co.uk/1/hi/sci/tech/3511678.stm

[jonfr]

it's going to be interesting....

[TheThorn]

I guess we'll find out tomorrow. But a 2000 km body 60+ AU from the sun hardly qualifies as a "planetary-sized object in the inner Oort cloud", as described in that Hubble task. Iffy on the planetary-sized part, not even close on the Oort cloud part.

So, either they mis-described it in that Hubble report, or our friends in the press have got it wrong.

If that's what it turns out to be, just a rather large, rather distant KBO, in a relatively circular orbit, well, that's cool, but the press conference hype was unnecessary.

[DippyHippy]

It's just been on the BBC television news, at 7:10am this morning... they're already calling it a new planet, which seems a bit premature, but they haven't stated anything that hasn't already been published online, either here or elsewhere.

[jonfr]

Originally posted by DippyHippy@Mar 15 2004, 07:17 AM
It's just been on the BBC television news, at 7:10am this morning... they're already calling it a new planet, which seems a bit premature, but they haven't stated anything that hasn't already been published online, either here or elsewhere.

The discovery of a mysterious object in our solar system is the topic of a listen-and-log-on news briefing on Monday, March 15, at 1 p.m. EST.

That doesn't sounds like an other small ice planet to me... :huh: :unsure: But we will see...

[Faulkner]

Sedna? My aunty's name is Sedna! :P

[NasaBoy]

I hope its a planet.......oh well i'll just tune into Nasa Tv today at 1:00 pm EST......

[Dave Mitsky]

Here are two more links concerning Sedna:


http://www.cnn.com/2004/TECH/space/03/14/p...very/index.html

http://www.msnbc.msn.com/id/3217961/


Dave Mitsky

[TheThorn]

And here's a really good link http://www.gps.caltech.edu/~chad/sedna/ to a page by Chad Trujillo, one of the discoverers, with all the details, including the discovery photos.

Smaller than Pluto, farther perihelion than anything else known, but with an aphelion of 850 AU or so, it's hard to call it an Oort cloud object (isn't the Oort cloud 10,000 - 50,000 AU out?).

It's not a planet. There are several similar sized KBO's.

I hate hype.