evidence for a 9th planet

[freyar]

I'm a little surprised this hasn't come up already! Two CalTech astronomers have published evidence for the existence of a 9th planet (NOT a dwarf planet like Pluto or Sedna) based on the orbits of Kuiper belt objects. (This is similar to the way Neptune was found by noticing its effects on the orbits of other planets.) The new planet is expected to have a mass over 10x that of the earth and an orbital period of over 10,000 years. Some other scientists have been a bit more cautious that this might be a false alarm, so we'll see if someone can confirm the discovery by actually finding it on a telescope in the next decade or so.

Astronomical Journal

 

[megamania]

Saw this article yesterday but as it is not proven I didn't speak of it. First we have 9 planets... then 8 now back to nine...... make up your minds

 

[Morrus]

Yeah, it's kind of a "wait and see" situation. Is there any way astronomers can calculate exactly where to direct their telescopes? I assume that far out, there's not a lot of light for it to reflect. Does that make the job harder?

 

[Janx]

per the article I read, the prediction was made by the guy who computed that Sedna existed (which he named) (which I didn't know existed)...

I guess the side problem is, we need an updated list of all the planet-things known in the Sol system, because many of us grew up with the 9 standard ones and are still grieving over the loss of Pluto from that list to have kept up.

 

[Morrus]

Grieving? I'm pretty sure astronomers will just fight through the tears and use their telescopes anyway!

 

[Dioltach]

Pluto's going, "Oh that guy back there? Yeah, he's been around for a while. Of course nobody bothered to ask me about him..."

 

[freyar]

Saw this article yesterday but as it is not proven I didn't speak of it. First we have 9 planets... then 8 now back to nine...... make up your minds

Yeah, I'm not entirely sure why this got so much press compared to other "false alarms" except maybe that one of the coauthors has a good track record on this kind of thing (as noted by Janx).

Yeah, it's kind of a "wait and see" situation. Is there any way astronomers can calculate exactly where to direct their telescopes? I assume that far out, there's not a lot of light for it to reflect. Does that make the job harder?

Some quotes from the press release indicate that they do have a target area for a search, but I didn't find it in a quick skim of the actual paper. But, you're right, there's not a lot of light for it to reflect, and it's hard to know how reflective the planet itself will be. It could be quite dim.

 

[Umbran]

Some quotes from the press release indicate that they do have a target area for a search, but I didn't find it in a quick skim of the actual paper.

How's this? It is by Mike Brown, one of the folks from the paper you linked to....

http://www.findplanetnine.com/p/blog-page.html

"The biggest unexplored territory is where, statistically, it is most likely to be: near aphelion. Sadly, aphelion is also very close to the Milky Way galaxy. Ugh.

So where is it? Probably distant. 500 AU+. Probably fainter than 22nd magnitude. Very possibly in the middle of the Milky Way galaxy."

When they say that it is "very close to the Milky Way" they mean in terms of apparent position in the sky - basically, you have to try to find it in the wash of light from the Milky Way, which makes it hard.

 

[Tonguez]

Including the named Dwarfs isn't there something like 20 Planet-things in the Solar system now? These kinds of announcements don't really spark the imagination like they use to as Planets are getting to be a bit common - its like they're out there just trying to find a little bit of space

 

[Morrus]

How's this? It is by Mike Brown, one of the folks from the paper you linked to....

http://www.findplanetnine.com/p/blog-page.html

"The biggest unexplored territory is where, statistically, it is most likely to be: near aphelion. Sadly, aphelion is also very close to the Milky Way galaxy. Ugh.

So where is it? Probably distant. 500 AU+. Probably fainter than 22nd magnitude. Very possibly in the middle of the Milky Way galaxy."

What does "close to the galaxy" mean in this context? Obviously it's in the galaxy; does that refer to it being in the direction of the galactic centre and thus possibly hard to see against the brighter background in that direction?