Astrophysicists in charge of the European Planck satellite recently reported that the data gathered by their space telescope reveals that scientists might have mistakenly calculated the first stars’ age. New data shows that first stars lit up 140 million years later than previously stated.
This difference of 140 million years might not seem that significant in the context of the 13.8-billion-year history of the cosmos, but proportionately it’s actually a very big change in our understanding of how certain key events progressed at the earliest epochs,”
said Prof George Efstathiou, chief of the Planck Science Collaboration.
Earlier researches assessed the date of the first-star formation around 420 million years after the Big Bang. Planck telescope revealed that the first hot giants lit up 560 million years after the big event.
The European Space Agency’s (ESA) team based their findings on a more accurate mapping of the subtle polarization of the Cosmic Microwave Background (CMB), or the ‘afterglow’ following the Big Bang, across the visible Universe.
Planck mapped the “oldest light” in the universe, which still washes over the Earth these days, between 2009 and 2013. CMB can provide a lot of data about Universe’s early formation, age, shape and ancient stars’ properties.
Scientists explained that CMB underwent several distortions before reaching us. One of these distortions was caused by a sudden change in the cosmos called reionization. Reionization was a result of the ignition of the first stars, which re-energized the cool atoms of hydrogen caused by the Big Bang.
The first stars fried the neutral hydrogen gas around them resulting in the emergence of the first heavy elements and clusters of electrons and protons, which originated in the “fried” hydrogen atoms.
By interfering with these clusters of protons and electrons, CMB underwent a delicate polarization. Planck analyzed this polarization and revealed that it occurred 560 million after the Universe’s emergence out of nothing.
The previous estimate for the peak of re-ionization was established by scientists based on data gathered by the NASA’s satellite WMAP at 420 million years. But the Hubble Space Telescope had also challenged that date because it wasn’t able to detect enough stars and galaxies to support the re-ionization theory.
Prof Richard McMahon from the Cambridge University said that Planck “effectively solves the conflict” between the two findings.
When asked what their opinion was on Planck’s new estimate, researchers said they were surprised but:
That’s OK. We like interesting physics; that’s why we’re physicists, so there’s no problem with that. It’s just we had this naïve expectation that the simplest answer would be right, and sometimes it just isn’t,”
commented Andrew Jaffe, astrophysicist from the Imperial College, in London.
Image Source: Monash Science News