Hubble finds birth certificate of oldest known star

Mar 07, 2013
This is a Digitized Sky Survey image of the oldest star with a well-determined age in our galaxy. The aging star, cataloged as HD 140283, lies 190.1 light-years away. The Anglo-Australian Observatory UK Schmidt telescope photographed the star in blue light. Credit: Digitized Sky Survey (DSS), STScI/AURA, Palomar/Caltech, and UKSTU/AAO

(Phys.org) —A team of astronomers using NASA's Hubble Space Telescope has taken an important step closer to finding the birth certificate of a star that's been around for a very long time.

"We have found that this is the oldest known star with a well-determined age," said Howard Bond of Pennsylvania State University in University Park, Pa., and the Space Telescope Science Institute in Baltimore, Md.

The star could be as old as 14.5 billion years (plus or minus 0.8 billion years), which at first glance would make it older than the universe's calculated age of about 13.8 billion years, an obvious dilemma.

But earlier estimates from observations dating back to 2000 placed the star as old as 16 billion years. And this age range presented a potential dilemma for . "Maybe the cosmology is wrong, stellar physics is wrong, or the star's distance is wrong," Bond said. "So we set out to refine the distance."

The new Hubble age estimates reduce the range of , so that the star's age overlaps with the universe's age—as independently determined by the rate of expansion of space, an analysis of the microwave background from the big bang, and measurements of .

This "Methuselah star," cataloged as HD 140283, has been known about for more than a century because of its fast motion across the sky. The high rate of motion is evidence that the star is simply a visitor to our stellar neighborhood. Its orbit carries it down through the plane of our galaxy from the ancient halo of that encircle the Milky Way, and will eventually slingshot back to the galactic halo.

This is an illustration of the oldest star ever found in our solar neighborhood. The aging star, cataloged as HD 140283, lies 190.1 light-years from Earth. Hubble Space Telescope observations narrowed the measurement uncertainty on the star's distance, and this helped refine the calculation of a more precise age of 14.5 billion years (plus or minus 800 million years). Because the aging star is relatively nearby, familiar stars and constellations as seen from Earth are in the sky, but in different locations. At upper left is the constellation Orion, which looks distorted from our new perspective in space. Just to the upper left of the foreground star is the Pleiades cluster. To the lower left of the cluster, our Sun has dimmed to an apparent magnitude of +7, placing it below naked-eye visibility. Credit: NASA, ESA, and A. Feild and F. Summers (STScI)

This conclusion was bolstered by the 1950s astronomers who were able to measure a deficiency of heavier elements in the star as compared to other stars in our . The halo stars are among the first inhabitants of our galaxy and collectively represent an older population from the stars, like our sun, that formed later in the disk. This means that the star formed at a very early time before the universe was largely "polluted" with heavier elements forged inside stars through nucleosynthesis. (The Methuselah star has an anemic 1/250th as much of the heavy element content of our sun and other stars in our solar neighborhood.)

The star, which is at the very first stages of expanding into a red giant, can be seen with binoculars as a 7th-magnitude object in the constellation Libra.

Hubble's observational prowess was used to refine the distance to the star, which comes out to be 190.1 light-years. Bond and his team performed this measurement by using trigonometric parallax, where an apparent shift in the position of a star is caused by a change in the observer's position. The results are published in the February 13 issue of the Astrophysical Journal Letters.

The parallax of nearby stars can be measured by observing them from opposite points in Earth's orbit around the sun. The star's true distance from Earth can then be precisely calculated through straightforward triangulation.

Once the true distance is known, an exact value for the star's intrinsic brightness can be calculated. Knowing a star's intrinsic brightness is a fundamental prerequisite to estimating its age.

Before the Hubble observation, the European Space Agency's Hipparcos satellite made a precise measurement of the star's parallax, but with an age measurement uncertainty of 2 billion years. One of Hubble's three Fine Guidance Sensors measured the position of the Methuselah star. It turns out that the star's parallax came out to be virtually identical to the Hipparcos measurements. But Hubble's precision is five times better that than of Hipparcos. Bond's team managed to shrink the uncertainty so that the age estimate was five times more precise.

With a better handle on the star's brightness Bond's team refined the star's age by applying contemporary theories about the star's burn rate, chemical abundances, and internal structure. New ideas are that leftover helium diffuses deeper into the core and so the star has less hydrogen to burn via nuclear fusion. This means it uses fuel faster and that correspondingly lowers the age.

Also, the star has a higher than predicted oxygen-to-iron ratio, and this too lowers the age. Bond thinks that further oxygen measurement could reduce the star's age even more, because the star would have formed at a slightly later time when the universe was richer in oxygen abundance. Lowering the upper age limit would make the star unequivocally younger than the universe.

"Put all of those ingredients together and you get an age of 14.5 billion years, with a residual uncertainty that makes the star's age compatible with the age of the universe," said Bond. "This is the best star in the sky to do precision age calculations by virtue of its closeness and brightness."

This Methuselah star has seen many changes over its long life. It was likely born in a primeval dwarf galaxy. The dwarf galaxy eventually was gravitationally shredded and sucked in by the emerging Milky Way over 12 billion years ago.

The star retains its elongated orbit from that cannibalism event. Therefore, it's just passing through the solar neighborhood at a rocket-like speed of 800,000 miles per hour. It takes just 1,500 years to traverse a piece of sky with the angular width of the full Moon. The star's proper motion angular rate is so fast (0.13 milliarcseconds an hour) that Hubble could actually photograph its movement in literally a few hours.

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Lurker2358
2.7 / 5 (30) Mar 07, 2013
Also, the star has a higher than predicted oxygen-to-iron ratio, and this too lowers the age. Bond thinks that further oxygen measurement could reduce the star's age even more, because the star would have formed at a slightly later time when the universe was richer in oxygen abundance. Lowering the upper age limit would make the star unequivocally younger than the universe.


Circular reasoning.

You are limiting the stars age by your BELIEVED age for the universe, when in fact the star may be a piece of remnant evidence telling you that your universe age is actually wrong.

In fact, it's actually absurd to say that you would restrain the star's age by the universes age, because the universe must be older than the oldest entity it contains. It is not conceivable to measure the age of the universe directly, only the age of the oldest entity it contains which you can observe, because the universe could be much older than any observable entity it contains...

Fail.
rkolter
4.3 / 5 (20) Mar 07, 2013
Actually it's quite reasonably concievable to measure the age of the universe, and we have quite an accurate measurement of it. They are not "restraining the star's age by the universes age" - they are saying the original measurement was not as accurate as teh current measurement, which happens to allow the star's age range to overlap with the purported age of the universe.

Not a fail.
Parsec
4.8 / 5 (20) Mar 07, 2013
@Lurker2358 in no way did this article try and constrain the age of the star beyond what was either directly measured or by what we currently understand about stellar evolution. 14.5 billion years is still older than the estimated age of the universe. It is only by including the possible errors in the estimation ( - 800 million) that the age falls inside the age of the cosmos. It is fair to say that further refinements will adjust the age even lower.

Emphatically NOT a fail...
Widdekind
2.1 / 5 (7) Mar 07, 2013
Core-collapse SNe spew alpha-process elements, e.g. "oxygen" (since all the iron implodes into the remnant compact object). Whereas thermo-nuclear SNe spew iron peak elements (since the CNO white dwarves obliterate themselves in exploding). Ipso facto, high O:Fe ratios imply the star formed from a mix of space gas, containing residues from CC SNe (which occur quickly, from big bright fast-burning stars); but before residues from TN SNe (which occur later, after small stars age into white dwarves) entered the mix. Et ipso facto, high O:Fe implies the star formed earlier, and hence is older. Yes ?
Q-Star
4.6 / 5 (18) Mar 07, 2013
high O:Fe implies the star formed earlier, and hence is older. Yes ?


No, it implies the star formed later, and is younger. If nothing else is considered. But the process of birth, main-sequence, and death is a quick (< 10 millions years) for very massive stars, so a very old star could still have metals, but not as much as later generations of stars. The star in this article is stated as having 1/250 the metals as stars of the same class found nearby,,, which is why they think this is so much older, and migrated. It's a Population III star, but born in an environment with some metals,,,

Google up "Star Metallicity Population classification" for more complete descriptions.
Tuxford
1.6 / 5 (21) Mar 07, 2013
Still another kluge to the Big Bang Fantasy. Clearly stellar evolution models are wrong. Assumptions piled on top of assumptions in this article.
Genep34
3 / 5 (6) Mar 07, 2013
i don't understand how the oldest star is in the milky way - surely the milky way isn't the oldest galaxy
Lurker2358
1 / 5 (16) Mar 07, 2013
i don't understand how the oldest star is in the milky way - surely the milky way isn't the oldest galaxy


It would appear to be a rogue star, perhaps captured from some other source.

Although the more likely solution is that scientists just suck at dating space objects, as all calculations of space objects ages are based on certain assumptions (direct measurements of age are impossible,) these assumptions are:

Assumed mass
assumed composition
assumed distance
assumptions about the required conditions for various nuclear reactions.

The actual conditions for a star cannot be modeled, even in a laboratory, because the laser fusion facilities do not "actually" model stellar core conditions, only stellar core temperatures for like a picosecond. So they get a nuclear reaction, but what they get can't reasonably be what is "really" happening inside a star under sustained temperature and pressure.

Basically it's a bunch of guesses; citation: error margins for betelgeuse...
jsdarkdestruction
4.7 / 5 (13) Mar 07, 2013
i don't understand how the oldest star is in the milky way - surely the milky way isn't the oldest galaxy

"Hubble finds birth certificate of oldest known star"
note "oldest known". their are probably older stars out there but we dont have the ability to detect them as they are small slow burning stars which dont stick out outside of our galaxy as much as inside.
DarkHorse66
2 / 5 (5) Mar 07, 2013
re: uncertainty estimates.

I can see that an uncertainty factor for this star is given in the article. But the article appears to be treating the age of the universe as an absolutely precis number (yeah, right), without uncertainty and this would add an influence as to which side of the universe's real starting date that stellar birth truely might have taken place. That does make the whole story a bit one sided. So, can anybody give an idea of what the overal uncertainty for the calculations and data is, that determines the overall age of the universe itself? And, since uncertainties have a nasty habit of interacting and combining, just how might this other uncertainty impact on the final result for the star?
Cheers, DH66
Isaacsname
2.5 / 5 (2) Mar 07, 2013
When they estimate the age of a star from it's luminosity, are they considering interstellar dust/clouds that may interfere with light ?
yash17
1 / 5 (10) Mar 07, 2013
This one (could also plus other cosmological data) is a clue for us that "The Big Bang theory" is really need evaluation or at least little revising.
ROBTHEGOB
1.3 / 5 (16) Mar 08, 2013
I told you before: THERE WAS NO BIG BANG!
Digi
5 / 5 (2) Mar 08, 2013
A fascinating star, one the Hubble can even detect moving. It's great age make it a huge draw for more intense study - has it any exoplanets I wonder?
matthew_r_lilly
1.5 / 5 (10) Mar 08, 2013
Funny... people think big bang, yet forget the universe is infinite in all directions. Isn't it possibly, our microscopic "big bang" is simply one of infinite big bangs happening outside our tiny reach of sight? We could simply be seeing the farthest reach of the next closest big bang results.
Pkunk_
2.6 / 5 (5) Mar 08, 2013
Actually a Star like this can strengthen the case for the Big Bang model. The age is within margin of error quite near to the calculated Age of the universe.
And there is no such thing as "oldest" star. In fact there are millions of "oldest" stars since within a few million years of the Big Bang stars were forming all over the place. In a few years they probably will start finding stars of a similar age , but not more in the Andromeda galaxy.
If you detect a Star so old it means that the cosmic "soup" of H2 after the Big Bang was very well distributed to every corner of the Universe.
katesisco
1 / 5 (5) Mar 08, 2013
The key here is 'unpolluted.' This star is long lived due to its pure gas birth. In looking at our zoo now do we see stars being born in this 'unpolluted' environment of pure gas?
They would have the characteristics of being perfect spheres and have rotations of very slow periods and be dim due to not burning fast. If they exist they would be very hard for us to see.
jwillis84
5 / 5 (6) Mar 08, 2013
it's just passing through the solar neighborhood at a rocket-like speed of 800,000 miles per hour. It takes just 1,500 years to traverse a piece of sky with the angular width of the full Moon. The star's proper motion angular rate is so fast (0.13 milliarcseconds an hour) that Hubble could actually photograph its movement in literally a few hours.

Pretty spry for an Ancient.
Lurker2358
1.5 / 5 (15) Mar 09, 2013
Pkunk:

The Big Bang is a hypothesis.

You can't use a theory or hypothesis as evidence of itself, moron.

Therefore you cannot use the Big Bang Theory (Hypothesis really,) nor anything dated based on that theory, as a limiting factor when determining the age of anything in the universe.

The age of objects MUST be interpreted as evidence for or against any theory explaining the minimum age of the universe, because "existence" can't be younger than it's contents.

The only way they date the universe is by calculating what they think is the age of radiation or objects contained by the universe, and saying the universe must be at least slightly older.

the way you people treat this, you would throw out the evidence of the star's age, just because it's older, which is the wrong thing to do.

The existing model and calculated age of the universe must be changed to fit the evidence, not the other way around.

BB is almost certainly wrong anyway, for reasons too complicated to discuss here.
yash17
1 / 5 (7) Mar 11, 2013
So, this is the modification.
Assume there was a real "Big Bang". Then from a point of that "Bang" happening, cosmos objects to spread away to entire directions. In GR language, the space expands. But we need to modify something. We need to revise the age of the Universe, since 13.7 billion years is extremely too young for the Universe, and we have been aware that. Many cosmological observations have indicated that. Keep with us all regulations, observations, theories (with all honest & sincere improving interpretations & translations).
Fellows, 13.7 billion years for Universe age is extremely too small. The age of Universe is infinite, or Universe is eternal. Mark the point we assume the "Bang" to happen as Universe nucleus, while (with new interpretation) the "Bang" is still going on and on, eternally. And again, we have noticed its place. It is behind between Ursa Major and Leo constellations. Then, we will get the Universe structure is actually "Cloud and rain model."
1parsec29
1 / 5 (5) Mar 11, 2013
I still belive time is relative. Why we bother so much the linear-time when we have more than enough space to all diraction and level? This "little" star show us people to think over the age of visible universe and find the error. We assuming datas and beliving in science its only one way to find the truth, other way to have a good question. Expl. When the extra dimension left our plane of existance? How about if it left never and exist right under our feet through the stars which is the time of our beloved holographic universe. We thought enough old style, let start to think different.
Fleetfoot
5 / 5 (8) Mar 11, 2013
So, can anybody give an idea of what the overal uncertainty for the calculations and data is, that determines the overall age of the universe itself?


The WMAP page gives you the current numbers:

http://map.gsfc.n...age.html

"we can estimate the age of the universe to about 0.4%: 13.77 ± 0.059 billion years!"

It's also important to understand what the numbers mean. Typically the distribution should be gaussian so 59 million years is the standard deviation. That means there's a 68.3% chance the age lies within those bounds, 95.6% within double that, etc.:

http://ned.ipac.c...re5.jpeg

However, the Hubble Constant is calculated from distances calibrated from the distance to the LMC. This article summarises a recent revision of that which may increase the age of the universe by a couple of percent:

http://phys.org/n...axy.html

Cosmology is an ongoing science :-)
ValeriaT
1 / 5 (7) Mar 11, 2013
we can estimate the age of the universe to about 0.4%: 13.77 ± 0.059 billion years!
The whole CMBR based support of Big Bang cosmology is a nifty example of circular reasoning, because the existence of CMBR is explained like the consequence of expansion of photon wavelength during its aging - well, and the age of Universe is derived from wavelength of CMBR photons expanded. In AWT the Universe is steady-state and the red shift is the consequence of light scattering with density fluctuations of vacuum in similar way, like the changes of wavelength of ripples during their spreading along water surface. This simple model can be falsified experimentally, because it leads into prediction, that the speed of Universe expansion is wavelength dependent in similar way, like the scattering of ripples at the water surface. It means, when being observed in radiowaves, then our Universe would appear collapsing instead, which can be checked both with blue shift, both with positive violation of
ValeriaT
1 / 5 (7) Mar 11, 2013
The blue shift of radiowave sources was observed with Pioneer masers, which serve as a reliable wavelength reference source. The violation of inverse square law was detected during ARCADE-2 observation of distant radiowave sources. In accordance with it the astronomers observed, that the distant galaxies are shrinking in size instead of expanding. From the above model follows, that in CMBR wavelengths the scattering effects (dark matter, dark energy, Sachs-Wolf effects) should disappear from our universe and it has been observed too. So we have a theory, which predicts the same effects, like the Big Bang model for visible light and it remains predictable for another wavelengths, while it doesn't assume the unphysical processes like the initial singularity and formation of Universe "from nothing"...
Q-Star
4 / 5 (12) Mar 11, 2013
The whole CMBR based support of Big Bang cosmology is a nifty example of circular reasoning, because the existence of CMBR is explained like the consequence of expansion of photon wavelength during its aging - well, and the age of Universe is derived from wavelength of CMBR photons expanded. In AWT the Universe is steady-state and the red shift is the consequence of light scattering with density fluctuations of vacuum in similar way, like the changes of wavelength of ripples during their spreading along water surface. This simple model can be falsified experimentally, because it leads into prediction, that the speed of Universe expansion is wavelength dependent in similar way, like the scattering of ripples at the water surface. It means, when being observed in radiowaves, then our Universe would appear collapsing instead, which can be checked both with blue shift, both with positive violation of,,,,,


,,, positive violation of the AWT electron duck principle.
Q-Star
3.9 / 5 (11) Mar 11, 2013
The blue shift of radiowave sources was observed with Pioneer masers, which serve as a reliable wavelength reference source. The violation of inverse square law was detected during ARCADE-2 observation of distant radiowave sources. In accordance with it the astronomers observed, that the distant galaxies are shrinking in size instead of expanding. From the above model follows, that in CMBR wavelengths the scattering effects (dark matter, dark energy, Sachs-Wolf effects) should disappear from our universe and it has been observed too. So we have a theory, which predicts the same effects, like the Big Bang model for visible light and it remains predictable for another wavelengths, while it doesn't assume the unphysical processes like the initial singularity and formation of Universe "from nothing"...


Universe riding on the backs of electron ducks transversely through the aether,, it that what ya meant to say?
Fleetfoot
5 / 5 (8) Mar 11, 2013
we can estimate the age of the universe to about 0.4%: 13.77 ± 0.059 billion years!
The whole CMBR based support of Big Bang cosmology is a nifty example of circular reasoning, because the existence of CMBR is explained like the consequence of expansion of photon wavelength during its aging - well, and the age of Universe is derived from wavelength of CMBR photons expanded.


Nope, wrong way round. The age is determined from the Hubble Constant and measurements of density. That can then give the redshift, but there are many other checks too.

In AWT the Universe is steady-state and the red shift is the consequence of light scattering with density fluctuations of vacuum in similar way, like the changes of wavelength of ripples during their spreading along water surface.


However, water ripples don't change their wavelength in water of constant depth.

This simple model can be falsified experimentally, ..


and it was even before Zwicky proposed it as he noted.
Fleetfoot
5 / 5 (4) Mar 12, 2013
The age is determined from the Hubble Constant and measurements of density
The current estimation of Universe age 13.74 ± 0.11 billion years is based on nine-year data release of WMAP spaceprobe


Exactly, WMAP gives the model parameters and the Hubble constant is then a scaling factor.

If the transverse waves at the surface of water ... and the light waves are transverse waves too


Light is in the bulk of the vacuum, surface waves are not a valid analogy. Neither bulk nor horizontal transverse waves exist in water.

why this scattering wasn't considered in interpretation of red shift already?


As I have told you many times before, Zwicky pointed out in the very first paper that ever suggested the Tired Light model that scattering is not a possible mechanism, it was already well known that scattering is frequency dependent while cosmological redshift is not. Some other explanation would be required if Tired Light hadn't already been falsified.