
A strange lonely planet found without a star - evo_9
http://phys.org/news/2013-10-strange-lonely-planet-star.html
======
sramsay
The "artist's rendering" is always my favorite part.

Astronomer: We want something sort of like Jupiter, but purple.

Artist: Can I do that big red storm thing?

Astronomer: No, no. Don't do that. We don't know if there's a storm. We used
blackbody radiation to find it.

Artist: So wait, it's supposed to be black?

Astronomer: No! It's gotta be PURPLE.

Artist: But you said . . .

Astronomer: Never mind. Just make it look lonely. And don't put any stars
around it.

~~~
aortega
>We used blackbody radiation to find it.

Pardon my pedantry but that's another way to say "we used regular light to
find it". If I remember my physics right, stars, like a candle or an
incandescent light bulb emit light as blackbody radiation.

~~~
guard-of-terra
Light bulbs don't emit black body radiation. They don't nearly have enough
black body temperature for bright yellow light. I guess tungsten has different
emission pattern.

~~~
gus_massa
I measured the emission spectrum of a tungsten lamp in the laboratory a few
years ago. I don’t remember all the details, but in the visible spectrum the
tungsten the amount or radiation that the tungsten lamp emits is roughly
0.3-0.4 times the radiation that a black body would emit.

I googled a little and found these two articles:

1)
[http://articles.adsabs.harvard.edu/full/seri/ApJ../0061//000...](http://articles.adsabs.harvard.edu/full/seri/ApJ../0061//0000146.000.html)
:

* In page 151 it has a graph of the emissivity of tungsten for different colors and temperatures. More emissivity for blue (A) than for red (C).

* In page 156 it has a greph of the difference between the color temperature and the true temperature. For 3000K, the difference is only ~100K. I think that it’s changes the color only slightly.

2)
[http://physicsed.buffalostate.edu/pubs/TPT/TPTDec99Filament....](http://physicsed.buffalostate.edu/pubs/TPT/TPTDec99Filament.pdf)

* More friendly version, with an experiments with actual lamps.

* In page 525 it explains that the emissivity if tungsten at that temperature in ~0.42 but you must introduce a correction because the glass of the lamp absorbs a 8% of the light.

------
hrjet
Apparently, the estimated number of orphan planets is "100,000 per star in the
galaxy!" [1].

The star equivalent to these orphan planets are called, well, orphan stars.
They are not bound to a particular galaxy and roam about freely in the space
between galaxies [2].

[1]: [http://news.discovery.com/space/astronomy/galaxy-filled-
with...](http://news.discovery.com/space/astronomy/galaxy-filled-with-
wandering-planets-study-finds-120224.htm)

[2]:
[http://aninews.in/newsdetail14/story80862/-039-mysterious-03...](http://aninews.in/newsdetail14/story80862/-039-mysterious-039-galaxy-
halos-produced-by-orphan-stars.html)

~~~
worldsayshi
I wonder what the chances are for orphan planets to wander into a solar
system. I suppose that could wreak quite some havoc.

~~~
uchi
The chances are incredibly small.

~~~
worldsayshi
If there are 100,000 free floating planets per star, and it's still an
incredibly small chance that one wanders into a solar system it gives you some
slight sense of proportion.

------
sdfjkl
Reminds me of one of George R.R. Martin's incredibly depressing earlier works:
[http://en.wikipedia.org/wiki/Dying_of_the_light](http://en.wikipedia.org/wiki/Dying_of_the_light)

 _A rogue, an aimless wanderer, creation’s castaway; this world was all those
things.

For uncounted centuries it had been falling, alone, without purpose, falling
through the cold lonely places between the suns. Generations of stars had
succeeded each other in stately sweeps across its barren skies. It belonged to
none of them. It was a world in and of itself; entire. In a sense it was not
even part of the galaxy; its tumbling path cut through the galactic plane like
a nail driven through a round wooden tabletop. It was part of nothing._

~~~
redler
For something one might imagine as a coda to Dying of the Light -- and even
more depressing -- try the 2011 Lars von Trier movie _Melancholia_.

[http://www.imdb.com/title/tt1527186/](http://www.imdb.com/title/tt1527186/)

------
gavinpc
Am I the only one who thought this was about a travel guide with no rating?

~~~
mkingston
You should be ashamed of yourself (I jest)

------
mutagen
I just submitted the arxiv.org link to the paper but this article is more
accessible. Fascinating discovery!

~~~
GFischer
Since you mention it, I'll link it:

[http://arxiv.org/abs/1310.0457](http://arxiv.org/abs/1310.0457)

------
hrjet
The article says that such planets have been observed previously, but only
indirectly. I found an article about those previous discoveries:
[http://arstechnica.com/science/2011/05/exoplanets-
without-a-...](http://arstechnica.com/science/2011/05/exoplanets-without-a-
star-galaxy-teems-with-lonely-jupiters/)

------
neur0mancer
Do they captured a real picture of the planet or the image is artificialy
colored?

~~~
manachar
> Artist's conception of PSO J318.5-22. Credit: MPIA/V. Ch. Quetz

From the image caption of the article.

~~~
neur0mancer
I mean, the other image[1].

[1]
[http://cdn.physorg.com/newman/gfx/news/2013/1-astrangelone.j...](http://cdn.physorg.com/newman/gfx/news/2013/1-astrangelone.jpg)

~~~
hrjet
The planet radiates only in Infra-Red, so the frequencies have been surely
mapped into our visible spectrum.

------
asgasdga
There was a short story about humans settling on such a planet:
[http://www.kuro5hin.org/story/2002/12/21/17846/757](http://www.kuro5hin.org/story/2002/12/21/17846/757)

------
pavel_lishin
I wonder if it has any moons.

~~~
enraged_camel
Or space stations...

~~~
tghw
That's no moon.

~~~
prawn
C'mon, I left Slashdot to escape this sort of "Someone mentioned a moon, so I
must make a Death Star joke" default.

~~~
tghw
Really? Those three words cause you such distress that you abandoned an entire
forum?

And to be clear, someone mentioned a moon _and_ a space station.

~~~
prawn
"escape this sort of"

------
pagejim
Are they sure it's a planet. Could be a large spaceship

~~~
skore
This really interests me as well - how do they know that it's a 12 million
years old planet?

I suppose a big reason would be that it does give off a heat significant (if
not AS significant) signature to begin with - a large spaceship would very
likely try to conserve as close to 100% of its energy.

Then again - what about a dyson sphere that is still under construction?

------
digerata
That's not a planet... ;)

~~~
groovy2shoes
...it's a space station!

~~~
jburwell
... I have a bad feeling about this. (Everyone take a drink)

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afterburner
Neat, I didn't expect we'd find one of these for some time, being all unlit in
between stars.

I wonder how many Earth-size orphan planets there are. They would be even
harder to find, without all that heat coming off them.

------
estebank
Oh great! I[1] was wondering where I left it!

[1]: [http://ipaz.info/wp-content/uploads/principito.gif](http://ipaz.info/wp-
content/uploads/principito.gif)

------
FajitaNachos
So what happens to planets who orbit a star that dies? It seems like they
would be come orphans. That was my first thought. I know next to nothing about
the Universe.

~~~
troels
When a star "dies", it goes through some phases, there one of them is that is
grows really big. Planets would presumably be consumed in this process. In any
case, a star doesn't disappear when it dies. It just ceases burning.

~~~
Daniel_Newby
Some stars explode with such energy that they evaporate. The thermal motion of
the gas exceeds the gravitational binding energy. Any outer planets simply
drift off into the cosmos.

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ck2
What if it is just in a REALLY big orbit.

Something is illuminating it, so it must be remotely near a star, we cannot
even image pluto like that.

~~~
wtallis
I'm pretty sure they're just measuring the blackbody radiation it's giving off
in the infrared spectrum. This thing is about half the mass necessary to
ignite fusion and become a brown dwarf, and it's very young, so it's still got
a lot of heat.

~~~
hrjet
I wonder if it were to get close to a star, would the heat from the star be
sufficient to ignite the fusion in the orphan planet?

~~~
cubancigar11
As I understand, a nearby star will strip off most of the gas and make it more
akin to a comet, so pretty much opposite of fusion will happen if it were to
get close to a star.

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tocomment
Couldn't this be a failed solar system with this as it's sun that just wasn't
big enough to ignite?

------
schtev
An evil, lightless place, where Elder Things dwell in their blasphemous cities
of impossible geometry...

------
Filligree
This is obviously not a planet. It hasn't cleared its orbit.

------
bitwize
Sha Ka Ree!

------
swamp40
Well, not everyone can be a star.

------
sien
The 50th anniversary is fine and everything, but this is going over the top
for PR.

Also, in the new series Mondas is no longer where they come from anyway.

