Strange ‘Methuselah’ Star Looks Older Than the Universe
The oldest known star appears to be older than the universe itself, but a new study is helping to clear up this seeming paradox.
Previous research had estimated that the Milky Way galaxy’s so-called “Methuselah star” is up to 16 billion years old. That’s a problem, since most researchers agree that the Big Bang that created the universe occurred about 13.8 billion years ago.
Now a team of astronomers has derived a new, less nonsensical age for the Methuselah star, incorporating information about its distance, brightness, composition and structure.
“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,” study lead author Howard Bond, of Pennsylvania State University and the Space Telescope Science Institute in Baltimore, said in a statement. [Gallery: The Methuselah Star Revealed]
The uncertainty Bond refers to is plus or minus 800 million years, which means the star could actually be 13.7 billion years old — younger than the universe as it’s currently understood, though just barely.
This is a backyard view of the sky surrounding the ancient star, cataloged as HD 140283, which lies 190.1 light-years from Earth. The star is the oldest known to astronomers to date. Image released March 7, 2013.
CREDIT: A. Fujii and Z. Levay (STScI)
A mysterious, fast-moving star
Bond and his team used NASA’s Hubble Space Telescope to study the Methuselah star, which is more formally known as HD 140283.
Scientists have known about HD 140283 for more than 100 years, since it cruises across the sky at a relatively rapid clip. The star moves at about 800,000 mph (1.3 million km/h) and covers the width of the full moon in the sky every 1,500 years or so, researchers said.
The star is just passing through the Earth’s neck of the galactic woods and will eventually rocket back out to the Milky Way’s halo, a population of ancient stars that surrounds the galaxy’s familiar spiral disk.
The Methuselah star, which is just now bloating into a red giant, was probably born in a dwarf galaxy that the nascent Milky Way gobbled up more than 12 billion years ago, researchers said. The star’s long, looping orbit is likely a residue of that dramatic act of cannibalism.
Distance makes the difference
Hubble’s measurements allowed the astronomers to refine the distance to HD 140283 using the principle of parallax, in which a change in an observers’ position — in this case, Hubble’s varying position in Earth orbit — translates into a shift in the apparent position of an object.
They found that Methuselah lies 190.1 light-years away. With the star’s distance known more precisely, the team was able to work out Methuselah’s intrinsic brightness, a necessity for determining its age.
The scientists also applied current theory to learn more about the Methuselah star’s burn rate, composition and internal structure, which also shed light on its likely age. For example, HD 140283 has a relatively high oxygen-to-iron ratio, which brings the star’s age down from some of the earlier predictions, researchers said.
In the end, the astronomers estimated that HD 140283 was born 14.5 billion years ago, plus or minus 800 million years. Further observations could help bring the Methuselah star’s age down even further, making it unequivocally younger than the universe, researchers said.
The new study was published last month in the Astrophysical Journal Letters.
Watch Big Asteroid Buzz Earth This Weekend: 2 Live Webcasts
| Asteroid 2013 ET was sighted March 7 by the Virtual Telescope’s Gianluca Masi and Francesca Nocentini, remotely using a 100mm scope at Siding Spring Australia.
CREDIT: G. Masi & F. Nocentini
Editor’s Note: Unexpectedly strong winds and clouds have forced the Virtual Telescope Project to cancel its live webcast of the asteroid 2013 ET today. The next chance to see the asteroid will be Saturday, March 9, in a 3:15 p.m. ET webcast by the Slooh Space Telescope as detailed in the original report below:
An asteroid the size of a city block is due to make a close pass by Earth on Saturday (March 9), and you can get a front-row view via two back-to-back webcasts.
The asteroid 2013 ET was discovered March 3 by the Catalina Sky Survey based at the University of Arizona. During the flyby, the space rock will fly within 2.5 times the moon’s distance from Earth. On average, the moon is about 238,000 miles (about 383,000 kilometers) from Earth.
Asteroid 2013 ET is about 210 feet by 460 feet (64 meters by 140 m) in size, with some astronomers comparing its width to a football field. Its close approach to Earth comes just days after another space rock, the 33-foot (10 meters) asteroid 2013 EC, buzzed the Earth on Monday (March 4) at a range just inside the moon’s orbit. [See a video of asteroid 2013 ET]
The first asteroid 2013 ET event will occur today in a free live webcast from the Virtual Telescope Project in Ceccano, Italy, starting at 2 p.m. EST (1900 GMT). You can watch the asteroid webcast on SPACE.com here.
“No matter how many asteroids approach us, even within a few days, the interest for these intriguing cosmic objects is always very high,” Virtual Telescope founder Gianluca Masi, an astrophysicist, told SPACE.com. “I believe that these close approaches should be used to increase in the public a correct perception of the real situation, to avoid confusion and false alarms.”
You can visit the Virtual Telescope directly at: http://www.astrowebtv.org.
On Saturday (March 9), the online Slooh Space Telescope, which also offers stargazing events, will provide a free webcast of the asteroid from its observatory in the Canary Islands, off the coast of west Africa. The Slooh webcast will feature discussions by Slooh president Patrick Paolucci, Slooh engineer Paul Cox, and documentary filmmaker Duncan Copp. That show begins Saturday at 3:15 p.m. EST (2015 GMT).
“We only have a short viewing window of an hour or so from our Canary Islands observatory on March 9, but we wanted to give the general public a front row seat to witness this new asteroid in real time as it passes by Earth,” Slooh president Patrick Paolucci said in a statement.
The Slooh webcast will also be carried on SPACE.com, and can be accessed directly at the Slooh Space Camera website.
Asteroid 2013 ET is not quite bright enough to view through small backyard telescopes or binoculars, but should be nicely visible in the footage from the online telescopes.
This asteroid pass comes less than a month after two major space rock events: the close flyby of asteroid DA14 near Earth, and the impact of a meteor into Russia. And 2013 ET’s approach comes just days after the asteroid 2013 EC flew within 230,000 miles (370,000 km) of Earth early Monday.
“The recent flurry of asteroidal close calls and near misses, including the double whammy of DA14 and the Siberian meteor on February 15, is starting to make our region of space seem like a video game or pinball contest,” astronomer Bob Berman, columnist and contributing editor of Astronomy magazine, said in a statement. “This latest interloper arrives just as serious debates are unfolding as to the obvious need for more and better monitoring of potentially hazardous asteroids crossing our orbit — and even whether we should develop a ‘deflection’ system.”
NASA and other astronomers around the world regularly scan the night sky for signs of asteroids that could pose a potential impact threat to Earth.
Huge Russian Meteor Blast is Biggest Since 1908 (Infographic)
A rock from space about 55 feet across (17 meters) entered Earth’s atmosphere early on the morning of Feb. 15, 2013.
Before entering the atmosphere, the object weighed about 10,000 tons. An early estimate of the energy of the Russian meteor explosion is that it equaled about 30 atomic bombs of the type used on Hiroshima in World War II.
The Russian meteor is second only to an explosion that occurred in Siberia in 1908. In the so-called Tunguska event, a 130-foot-wide (40 m) object exploded, flattening trees over an 825-square-mile area (2,137 square km). Even larger impacts from space occurred before recorded human history.
The solar system was shaped by even bigger impacts from space. Fifty thousand years ago, a rock about 150 feet wide (46 meters) crashed into what is now Arizona. The crater is 0.7 mile in diameter (1.2 km). Impacts have occurred since the beginning of our solar system. In 1994, the planet Jupiter was assaulted by fragments from comet Shoemaker-Levy 9.
Big Story: Russia Meteor Blast is Biggest in 100 Years
The dramatic fireball that exploded over Russia was apparently the biggest such blast in more than a century, scientists say.
RAW VIDEO: Meteorite Crash in Russia Sparks Panic
A series of explosions in the skies of Russia’s Urals region, reportedly caused by a meteor shower, has sparked panic in three major cities.
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Russian Satellite Crash with Chinese ASAT Debris Explained (Infographic)
Analysts believe that on Jan. 22, 2013, debris from the destroyed Chinese satellite Fengyun 1C collided with a small Russian laser-ranging retroreflector satellite called BLITS (“Ball Lens in The Space”). After the impact, BLITS was knocked from its original orientation and is now spinning rapidly. Ground trackers are following at least two fragments of the BLITS satellite.
The BLITS nanosatellite was launched into a polar orbit by Russia on Sept. 17, 2009. The tiny satellite weighs 16.2 pounds (7.35 kilograms)
BLITS is essentially a glass ball, 6.7 inches in diameter (170 mm). Two outer hemispheres of low-refraction-index glass surround an inner ball lens made of high-refraction-index glass. One half of the sphere is covered with an aluminum coating. The satellite rotated for stability and to achieve a precise orientation. BLITS was used as laser ranging target by the International Laser Ranging Service for precision experiments.
The Fengyun 1C weather satellite was launched into a polar orbit by China on May 10, 1999. On Jan. 11, 2007 Fengyun 1C was intentionally destroyed. A “kinetic kill”anti-satellite vehicle was launched and intercepted Fengyun 1C at high speed. The collision shattered the satellite into many pieces.
The cloud of debris from Fengyun 1C has been spreading out as the fragments, traveling in different orbits, slowly move apart.
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