For more than a century, the star HD 140283 has been studied, but only now has its age been estimated: within hundreds of millions of years of the age of the Universe. Delivering a scoop, my Nature article, Nearby star is almost as old as the Universe, details this important new conclusion:
The team then exploited the fact that HD 140283 is in a phase of its life cycle in which it is exhausting the hydrogen at its core. In this phase, the star’s slowly dimming luminosity is a highly sensitive indicator of its age, says Bond. His team calculates that the star is 13.9 billion years old, give or take 700 million years. Taking into account that experimental error, the age does not conflict with the age of the Universe, 13.77 billion years.
The very first generation of stars coalesced from primordial gas, which did not contain appreciable amounts of elements heavier than helium, he notes. That means that as old as HD 140283 is, its chemical composition — which includes a low but non-zero abundance of heavy elements — shows that the star must have formed after the first stellar generation.
Conditions for making the second generation of stars, then, “must have been in place very early”, says Bromm. The very first stars are usually thought to have coalesced a few hundred million years after the Big Bang, he notes. Massive and short lived, they died after only a few million years — exploding in supernovae that heated surrounding gas and seeded it with heavier elements.
The Nature article contains more information about the research and characteristics of early stars.
Recent infrared images taken from the Hubble Space Telescope’s Wide Field Camera 3 are the deepest taken of the Universe, and they reveal several galaxies, including one that is the most distant object we’ve ever found. This galaxy is 13.29 billion light years (4.1 billion parsecs) from Earth and were first visible when the Universe was only 450 million years old (only 4 percent of what it is now). From my recent article in Nature, Galaxy found at record-breaking distance:
Scientists’ discovery of a large black hole in a relatively small galaxy is causing them to rethink our understanding of black holes and their growth. From my latest Nature article, Small galaxy harbours super-hefty black hole:
Are there massive black holes that move about the universe? In my recent article in Science notes, initial observations with the Hubble Space Telescope and follow-up data collection using NASA’s Chandra x-ray Observatory suggest this is the case. If so, then this would verify Einstein’s theory of general relativity under previously untested conditions.
Do Solo Black Holes Roam the Universe?
Even gravitational monsters can get the heave-ho. Two mysterious bright spots in a disheveled, distant galaxy suggest that astronomers have found the best evidence yet for a supermassive black hole being shoved out of its home.
Observations with NASA’s Chandra x-ray Observatory revealed that only one of the compact visible-light sources—a blob that lies about 8000 light-years from the galaxy’s estimated center—emits x-rays. The high-energy radiation is believed to be a sign that this blob is a supermassive black hole munching away on surrounding gas.
Even better than the image below, this short video explains how the big black hole may have formed.
Is the blob seen near the bright star Fomalhaut a planet or not? Only Hubble has ever seen the point of light, but new Hubble observations scheduled for end of May, plus a reanalysis of previous Hubble data may help settle the question. See my story posted May 23 at news section of Nature.
Infant galaxy offers tantalizing peek at early Universe
Astronomers are claiming a new benchmark in the quest to see the Universe’s first galaxies. By taking advantage of a rare cosmic zoom lens — where the gravity of a large mass magnifies light from objects in the distant background — a team of US and European researcher has spotted a galaxy so remote its light was emitted just 490 million years after the Big Bang, when the Universe was a mere 3.6% of its current age.
Read my entire article, which includes how existing and upcoming telescope capabilities could be used to investigate this galaxy further and what the find means for our understanding of the Universe’s number of galaxies.