Astronomers See the Glow of a Boiling Planet 56
The Bad Astronomer writes "For the first time, astronomers have detected the light from a 'super-Earth' exoplanet. The planet 55 Cancri e (with twice the radius and 8 times the mass of Earth) circles its host star every 18 hours, and is so hot it glows in the infrared. By observing in that wavelength, the astronomers measured the dip in light as the planet's glow was blocked by the star itself. This is the reverse of the usual method of detecting a planet as it blocks the light of its host star."
Re: (Score:3)
Re: (Score:2)
Get off your lazy ass and have a current version for Mac, and an HTML version for at least both platforms, will you? Less trolling, more doing.
How cold do you think it needs to be ? (Score:5, Insightful)
Re: (Score:1)
Before it doesn't emit infrared radiation?
Good point, but I would assume that it's got to be giving off quite a bit to be detectable from here.
Or maybe it's just very reflective.
Re:How cold do you think it needs to be ? (Score:4, Informative)
Re: (Score:2, Funny)
Ahhh.. Crematoria.
Re: (Score:3)
Norfair?
Re: (Score:2)
Is that the temperature for the WHOLE planet or the side which faces its sun ?
Re: (Score:1)
with 2700 C the dominant frequencies aren't infrared anymore. More like yellow.
Re: (Score:1)
They were looking at a wavelength of 4.5um - this probably isn't the peak wavelength the planet is emitting, but if it were, the source would need to be 370 C. Which I would call toasty.
Re:How cold do you think it needs to be ? (Score:5, Informative)
It's not the peak - TFA states the planet's temperature is about 2700C. Which I would call "infernal".
That does, however, explain how the IR emissions are high enough for us to detect here on Earth, light-years away - it's really, really, *really* hot.
Re:How cold do you think it needs to be ? (Score:5, Informative)
2700ÂC is not just infernal I'd think. That temperature is nearly half the temperature of the sun's photosphere (5500ÂC). Iron melts at 1538ÂC, and boils at 2862ÂC. There could be clouds of iron vapor and rains of molten iron there. If it had any kind of atmosphere it would likely be made up of iron and silicon vapor.
Re: (Score:1)
If it had any kind of atmosphere it would likely be made up of iron and silicon vapor.
Interesting ... it is said that silicon-based organic chemistry life is impossible because, unlike CO2, SiO2 is not a gas but a rock. Well, it seems now we have found a place where SiO2 actually is a gas...
Re: (Score:2)
If it had any kind of atmosphere it would likely be made up of iron and silicon vapor.
Interesting ... it is said that silicon-based organic chemistry life is impossible because, unlike CO2, SiO2 is not a gas but a rock. Well, it seems now we have found a place where SiO2 actually is a gas...
Sodium Oxide is too low temperature, but I think Li2O might have potential. Does anyone know the triple point of Lithium Oxide?
Re:How cold do you think it needs to be ? (Score:5, Funny)
...it's really, really, *really* hot.
Yea, but it's a dry heat...
Re: (Score:2)
Re: (Score:2)
Everything above 0K emits infra red.
Re: (Score:2)
Before it doesn't emit infrared radiation?
Absolute zero. All objects emit infrared. Better question: What's the sensitivity of the equipment measuring this?
super-Earth? (Score:1)
What exactly justified it to be called super-Earth? The size is close to Earth (half order of magnitude), but it is close to Venus as well, and Venus is hotter.
Re:super-Earth? (Score:5, Informative)
The only planets larger than Earth in the Solar system are the gas giants, so a super Earth is just a designation for a planet more massive than Earth, but not a gas giant.
Re:super-Earth? (Score:5, Informative)
What exactly justified it to be called super-Earth?
Earth-like but significantly bigger than earth. The planet in question is 8 times the mass of Earth with twice the radius so roughly the same density. It might only be a factor of 8 in mass but if you saw a person with 8 times the average mass, say ~600kg, you'd certainly call them super-sized! As for temperature Venus is hotter than Earth but with a surface temperature of 460C it's decidedly nippy compared to the planet in question which is just over 1700C.
Re: (Score:2, Informative)
The problem here is one of nomenclature and trying to define different terms for planets. In our Solar System there are no "super-Earth" sized planets, so until exo-solar planets were discovered there was no need for any classification for planets that sized. Basically there is a need to define planets smaller than the "small gas giants" like Neptune and Uranus and something larger than the size of the Earth or Venus.
Currently that is being called "Super Earth" because it shares many more characteristics
Re: (Score:2)
Re: (Score:1)
Re: (Score:1)
What exactly justified it to be called super-Earth?
It's bigger, stronger, faster, shoots infra-red beams, and, the dead give-away, has a red cape. Yeah. I went there.
Sauna world (Score:5, Funny)
I suggest we send Finnish astronauts. They actually like this sort of place.
"Cosmonaut Hämeenniemi! Have you reached the planet, what is it like!"
(long delay)
"Shhh... I'm relaxing"
Re: (Score:2)
^_^ (Score:3, Funny)
A watched planet never boils...
Re: (Score:2)
But it started boiling before we started watching it.
So Boil's law is not broken.
Re: (Score:2)
So you have created a universe with a better ratio of hospitable-to-inhospitable planets?
No?
Didn't think so.
Re: (Score:3)
Leave the AC alone. At least he exists!
Re: (Score:2)
We have no idea if they are really inhospitable to life. They are merely inhospitable to life as we know it. But, the bare fact is we don't know much, we have only a single working model to compare against which is hardly a scientific sample to draw any conclusions with.
you should have two dips (Score:2)
One small dip is when the planet is covering the sun.A larger dip is when the sun is covering the planet.
S+P vs S vs S +P - coveredfractionofsun*S.
When the planet is colder the first dip is larger and the second dip is less. With a hot planet I think both dips may well be measurable.
Re: (Score:2)
Sun before planet => intensity = intenisty of only the sun.
Sun behind planet => intensity = intensity of the sun - intensity of blocked part of the sun + intensity of the planet
sun and planet besides eachother => intensity = sun + planet