Ancient star system reveals Earth-sized planets forming near start of universe

January 27, 2015
Kepler-444 hosts five Earth-sized planets in very compact orbits. The planets were detected from the dimming that occurs when they transit the disc of their parent star, as shown in this artist's conception. Credit: Tiago Campante/Peter Devine

A Sun-like star with orbiting planets, dating back to the dawn of the Galaxy, has been discovered by an international team of astronomers.

At 11.2 billion years old it is the oldest star with earth-sized planets ever found and proves that such planets have formed throughout the history of the Universe.

The discovery, announced on 28 January (AEDT) in the Astrophysical Journal, used observations made by NASA's Kepler satellite. The scientific collaboration was led by the University of Birmingham and contributed to by the University of Sydney.

The star, named Kepler-444, hosts five planets smaller than Earth, with sizes varying between those of Mercury and Venus.

"We've never seen anything like this - it is such an old star and the large number of small planets make it very special," said Dr Daniel Huber from the University's School of Physics and an author on the paper.

"It is extraordinary that such an ancient system of terrestrial-sized planets formed when the universe was just starting out, at a fifth its current age. Kepler-444 is two and a half times older than our solar system, which is only a youthful 4.5 billion years old.

"This tells us that planets this size have formed for most of the history of the universe and we are much better placed to understand exactly when this began happening."

Dr Tiago Campante, the research leader from the University of Birmingham said, "We now know that Earth-sized planets have formed throughout most of the Universe's 13.8-billion-year history, which could provide scope for the existence of ancient life in the Galaxy."

Kepler-444: An ancient extrasolar system with five Earth-sized planets. This animation starts by showing us Kepler's field-of-view in the direction of the constellations Cygnus and Lyra. We are next taken to the vicinity of the Kepler-444 planetary system, located some 117 light years away. Kepler-444, the parent star, was formed 11.2 billion years ago when the Universe was less than 20% its current age. This pale yellow-orange star is 25% smaller than the Sun and substantially cooler. We see its five planets transiting in front of the stellar disc. Having sizes between those of Mercury and Venus, they cause a tiny dimming of the light received from the star during transit. The last segment of the animation emphasizes the compactness of this system. The five planets orbit their parent star in less than 10 days or, equivalently, at less than one-tenth Earth's distance from the Sun. In a way, this system may be thought of as a miniature version of the inner planets in our own Solar System. Credit: Tiago Campante/Peter Devine.

Together with their international colleagues the University's astronomy team used asteroseismology to determine the age of the star and planets. This technique measures oscillations - the natural resonances of the host star caused by sound waves trapped within it.

They lead to miniscule changes or pulses in the star's brightness and allow researchers to measure its diameter, mass, and age. The presence and size of the planets is detected by the dimming that occurs when the planets pass across the face of the star. This fading in the intensity of the light received from the star enables scientists to accurately measure the sizes of the planets relative to the size of the star.

Kepler-444 planets compared to the sized of planets in the inner solar system. Credit: NASA

"When asteroseismology emerged about two decades ago we could only use it on the Sun and a few bright stars, but thanks to Kepler we can now apply the technique to literally thousands of stars. Asteroseismology allows us to precisely measure the radius of Kepler-444 and hence the sizes of its planets. For the smallest planet in the Kepler-444 system, which is slightly larger than Mercury, we measured its size with an uncertainty of only 100km," Dr Huber said.

"It was clear early on that we had discovered something very unusual because we had five planets orbiting a very bright star - one of the brightest Kepler has observed. It is fantastic that we can use asteroseismology to date the star and determine just how old it is.

"In the case of Kepler-444 the planets orbit their parent star in less than 10 days, at less than one-tenth the Earth's distance from the Sun. Their closeness to their host star means they are uninhabitable because of the lack of liquid water and high levels of radiation. Nevertheless, discoveries like Kepler-444 provide important clues on whether a planet that is more truly comparable to Earth may exist. "We're another step closer towards finding the astronomers' holy grail - an Earth-sized planet with a one year orbit around a star similar to our Sun."

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26 comments

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foolspoo
4 / 5 (1) Jan 27, 2015
"It is extraordinary that such an ancient system of terrestrial-sized planets formed"

oh daniel, you should be cautious in projecting ignorance as phenomenon
katesisco
1 / 5 (8) Jan 27, 2015
Mes Mathis paper: http://milesmathi...core.pdf
As he points out correctly, radiation from the origin would not exist, so where does the 'radiation' described above come from?
Maggnus
5 / 5 (11) Jan 27, 2015
Mes Mathis paper: http://milesmathi...core.pdf
As he points out correctly, radiation from the origin would not exist, so where does the 'radiation' described above come from?


Back to Mathis again? That is quite the site BTW. He really riddles his arguments with fallacies and misunderstandings. The expanding earth theory is pretty far out there.

So you think he is correct when he suggests that "radiation from the origin would not exist". Can you elaborate as to why you agree with him?
vlaaing peerd
4.2 / 5 (5) Jan 27, 2015
They dated the star, but I see nothing that proves the planets weren't formed at a much later time. As I see it, those planets may just as well have formed just a few billion years ago.
yyz
5 / 5 (5) Jan 27, 2015
"At 11.2 billion years old it is the oldest star with earth-sized planets ever found..."

How does this system compare with the Methuselah planet, orbiting a white dwarf-pulsar binary at the edge of the globular cluster M4? The binary is estimated to be 12.7 billion years old: https://en.wikipe...620-26_b
RCole
5 / 5 (7) Jan 27, 2015
The Methuselah planet is not an earth-sized planet, being about 2.5 times the size of Jupiter.
TechnoCreed
4.5 / 5 (11) Jan 27, 2015
The Methuselah planet is not an earth-sized planet, being about 2.5 times the size of Jupiter.
Exactly! It should not be a surprise to find old gas giants. What is interesting here is to find solid core planets in the early universe when there was not supposed to be enough heavy elements for them to exist.
what_the_hell
not rated yet Jan 27, 2015
"Their closeness to their host star means they are uninhabitable because of the lack of liquid water and high levels of radiation."

Could be written as...

"Their closeness to their host star means they are uninhabitable, at least as of 11.2 billion years ago, because of the lack of liquid water and high levels of radiation."
Uncle Ira
4.3 / 5 (6) Jan 27, 2015
Mes Mathis paper: http://milesmathi...core.pdf
As he points out correctly, radiation from the origin would not exist, so where does the 'radiation' described above come from?


@ katie-Skippette, Chere, anybody ever tell you that you are really weird? Non? Well take it from me,,,, Chere you are the really weird Skippette.
reset
1 / 5 (5) Jan 27, 2015
He really riddles his arguments with fallacies and misunderstandings. The expanding earth theory is pretty far out there.

So you think he is correct when he suggests that "radiation from the origin would not exist". Can you elaborate as to why you agree with him?


He is bang on about the earths magnetic field observations. A polarity reversal of any field generated by flow can only be accomplished by reversing the direction of the flow...you feel that ground shaking?

Me neither.
Z99
5 / 5 (3) Jan 27, 2015
Let me wave my arms (in front of the mirrors, and in a smoke filled room) and say that by ~0.5 Myr post Big Bang, matter was sufficiently cool to begin gravitational condensation (I've not read the primary literature on this, which surely exists). Add 0.1 My for star formation, add 1-2 Gy for complete life cycle (massive stars only) and easily by 3 Gy post BB enough metals existed to form rocky planets. So, 13.8 - 3 = 11. The oldest rocky planets should be at least 11 Gy old. (and in special circumstances (hypermassive stars may have lifecycles of only 0.5 Gy), we may find some almost 13 Gy old.)
anonymous_9001
4.9 / 5 (17) Jan 27, 2015
Ren82,

Religion myths will remain a mystery to people because we can not know with precision the events taking place in the bronze ages. Creation myths generated by original storytellers travel thousands of years to the present and are constantly modified and retold my other storytellers. Thus, the tales change greatly on the way to current recollections and do not give an accurate picture of the original events. And that means we cannot be sure of the actual history. When someone says a a guy talked to a burning bush and a guy made a copy of himself in a virgin and then killed himself to absolve the sins he let happen in the first place and then came back as a zombie, it means that his knowledge is a sand tower.
pugphan
1 / 5 (11) Jan 27, 2015
"In my Father's house, there are many mansions," Jesus, NT. We keep looking for life out there, but truth be known, ALFs & ETs have been here all along. wwwweliveamonyoucom
Bhrash
1.6 / 5 (7) Jan 27, 2015
I know I am of limited intelligence and there is probably a logical explanation for this, so some one please share it with me. When I read an article of this nature, so many variables enter my mind that I don't see how the article can be anything more than a work of fiction. Here are just a couple. 1. How is it every star we look at, the orbital plane of the planets in that solar system are directly in line of site from their sun to our earth? Really! All orbits, everywhere? For the statisticians in here what are the odds of that happening in a random Galaxy? What are the odds of ANY orbital plane being exactly where ours is? 2. How do your calculations account for comets, asteroids, moons, meteors, planet alignment, etc. (your the space experts, how many other objects can we list here?) that can interfere with brightness of a star? This reminds me of medieval religions (all of them) that believed the earth was the center of everything and everything revolves around earth! I am waiti
anonymous_9001
5 / 5 (11) Jan 27, 2015
God take care for authenticity of Scripture. Apart from that all prophecies recorded in Scripture are came true.


Bullshit! I took a class on the Gospels in college. Those four book alone are inconsistent. You're not pulling the wool over my eyes.
Vietvet
4.9 / 5 (10) Jan 27, 2015
@BHrash

Not all stars have planetary orbits that are in line with earth, if that were the case we would see extra solar planets everywhere we looked.

It's the same with spiral galaxies. Some we observe face on, others edge on and everywhere in between.
Captain Stumpy
5 / 5 (12) Jan 27, 2015
You can not comment on the content and authenticity while you read it carefully
@renTROLL
1- you comment on it and YOU have not read it carefully
2- Anon HAS read it well enough so that the argument stated above stands as legit, and so have many other science minded people, including myself, which makes your argument one from stupidity and fallacious
3- until you can comprehend that there is such a thing as EVIDENCE, especially in science, that can be repeated, demonstrated and is considered the most accurate means to represent reality, via court or any other means, then you are simply stupidly ignoring reality for the sake of a belief

You would do well to stick to argument from your delusional faith, because it is far more likely that the SCIENTIST in a person using science and reason (like Anon) will read your bible more accurately than you will and ask pertinent questions

That is YOUR fallacy and problem
you DON'T comprehend/know your own tome
jazzy_j_man
Jan 28, 2015
This comment has been removed by a moderator.
TechnoCreed
5 / 5 (8) Jan 28, 2015
@ BHrash
Honestly, I do not see what you find so upsetting. Kepler observed more than 100000 stars and, so far, found 1013 planets. That makes 0.1 planet per star. What do you find so dizzying?
How is it every star we look at, the orbital plane of the planets in that solar system are directly in line of site from their sun to our earth? Really! All orbits, everywhere? For the statisticians in here what are the odds of that happening in a random Galaxy? What are the odds of ANY orbital plane being exactly where ours is?
If you like maths, the probabilities are explained here: http://certificat...ter.html
If you want a more prosaic answer, read: Will all the stars Kepler observes have transiting planets? http://kepler.nas.../faq/#a4

For your number 2 question I will be blunt: NO CHANCE AT ALL.
TechnoCreed
5 / 5 (8) Jan 28, 2015
@jazz_i_man
This kind of immature language has no place here. I have reported it and hope everybody will do the same.
Torbjorn_Larsson_OM
5 / 5 (8) Jan 28, 2015
@vlaaing_perd: It is a result of how we know planets form, from a protoplanetary disk. [ http://en.wikiped...pothesis ] (Not planets around white dwarfs/neutron stars though, they form from secondary debris disks after the star cataclysm is over. But that is dateable too.)

@TechnoCreed: "What is interesting here is to find solid core planets in the early universe when there was not supposed to be enough heavy elements for them to exist."

You got that backwards I think, gas giants demands more of what astronomers call metals. First, they have terrestrial cores of ~ 10 Earth masses, which the disk gas "core collapse" on. Second, "metal poor" gaseous disks seem to disperse faster, so they tend to have _less_ gas giants (as the gas collapse is interrupted).
Torbjorn_Larsson_OM
5 / 5 (7) Jan 28, 2015
@BHrash: We see exactly the number of transit systems that we expect from them being randomly tilted. And those are the only ones we _can_ see with the method, you seem to have confused posteriors with priors. The orientation is decided by the largest, random gas movement in the collapsing protoplanetary nebula.

**********

So, the trolls.

Of course, we don't know enough about geodynamo formation yet (a hard field) to know what the anti-geophysics troll claim.

And of course we have known since the 17th century (an easy field) that creationist magic is a meaningless claim (from thermodynamics of closed systems), and that we can't "deny" something that we know doesn't exist. So much for the anti-scientist troll.

Trolls must troll, however. All we can do is shake our heads and laugh at their infantile antics.
humy
5 / 5 (3) Feb 01, 2015
They dated the star, but I see nothing that proves the planets weren't formed at a much later time. As I see it, those planets may just as well have formed just a few billion years ago.


wouldn't that contradict absolutely everything science has deduced about planet formation?
TechnoCreed
5 / 5 (2) Feb 01, 2015
@Torbjorn
Do not forget that there are two operative models for planet formation; core accretion and disk instability. Even low metallicity stars should host gas giants formed by disk instabilities and in fact10% of gas giants can only be explained by the disk instability model. But, as a general rule, you are right, more gas giants form around high metallicity stars.

In my former comment I was just expressing my surprise to the fact that rocky planets are omnipresent without regard to the metallicity of their host stars.
deusexmakina
5 / 5 (2) Feb 28, 2015
several comments in this thread have given me avenues to explore, the religious ones are a nuisance and have almost made me close the page and stop reading. I am not gonna even say here wether I have superstitions of my own or not, just that a scientific discussion should remain so. those who seek truth will always remain objective and base their arguments on what facts we have available. those with an agenda will only get in the way of discovery. if there is any kind of god, I would like to know more about it, science does not exist to prove or disprove a narrow point of view, but to give us a greater understanding and control, or at least learn the limits of, the time and place we live in. The are never answers, only the questions we will have tomorrow after we have come to understand today. Please remain clinical and never forget the less passionate scientific method. This is not a church, pray and evangelize elsewhere (with my full support). Stop polluting this roundtable.
viko_mx
1.3 / 5 (3) Feb 28, 2015
If the gravitation was so powerfull to make pasible formation of cosmic structures after the hipotetical big bang in the distatnt past, the universe would have colapsed on itself long ago. This is the disturbing problem for big bang religious proponents and the reason to invent such a complex strategy for universe expansion that we can see on popular pictures.

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