Outer space: Values ​​calculated from starbursts provide further puzzles

Science astrophysics

Precise surveying of the universe intensifies cosmological puzzle

The object is 16,000 light-years from Earth "G299" is the remnant of a type Ia supernova

Located 16,000 light-years from Earth, object G299 is the remnant of a Type Ia supernova

Source: NASA/CXC/U.Texas

You can listen to our WELT podcasts here

In order to display embedded content, your revocable consent to the transmission and processing of personal data is required, since the providers of the embedded content as third-party providers require this consent [In diesem Zusammenhang können auch Nutzungsprofile (u.a. auf Basis von Cookie-IDs) gebildet und angereichert werden, auch außerhalb des EWR]. By setting the switch to “on”, you agree to this (which can be revoked at any time). This also includes your consent to the transfer of certain personal data to third countries, including the USA, in accordance with Art. 49 (1) (a) GDPR. You can find more information about this. You can withdraw your consent at any time via the switch and via privacy at the bottom of the page.

Astronomers are gathering the most accurate data yet on the composition and extent of the universe. But the values ​​calculated from starbursts create another mystery. Is a previously unknown physical phenomenon involved?

WWhat is the universe made of – and how fast is it expanding? An international research team has found the most accurate answers to these questions to date. To do this, the astronomers evaluated data from over 1,500 stellar explosions up to 10.7 billion light-years away. The problem: The speed of cosmic expansion determined in this way is in clear contradiction to a value determined using another method. The scientists write that this points to the existence of a previously unknown physical phenomenon in the young cosmos in the Astrophysical Journal.

As part of the Pantheon+ project, the team studied the brightness of stellar explosions of a certain type over time collected and evaluated. When a star like our sun has completely used up its nuclear energy supply, it ends up as a white dwarf. Only about the size of the earth, such a remnant of stars slowly cools down over billions of years. However, if such a white dwarf forms a binary system with a second large star, it can snatch matter – mainly hydrogen gas – from it.

Eventually, a white dwarf will have accumulated so much fresh hydrogen that a thermonuclear explosion occurs – a type Ia supernova. Such explosions are extremely valuable to astronomers because they all light up equally brightly. How brightly such a supernova shines in the terrestrial sky therefore depends only on its distance. From the observed brightness of the starburst, astronomers can calculate the distance of the supernova.

also read

LISA Pathfinder program will demonstrate, in orbit, the technologies for LISA, the ESA-NASA Laser Interferometer Space Antenna gravity wave observatory.  LISA Pathfinder will be launched in 2012. It will be packed with radical instrumentation and technology to pave the way for LISA, the world's first space-based gravity wave detector which will open a new window on the Universe by measuring gravitational waves generated by exotic objects such as collapsing binary star systems and massive black holes.  LISA is a candidate mission in ESA¿s Cosmic Vision 2015-2025 programme.  The basic principle of LISA is to measure the changes in distance between freely floating 'test masses', literally, small gold/platinum blocks held in place by carefully controlled electrostatic fields.  LISA will rely on three core technologies to be tested by LISA Pathfinder: gravitational reference sensors, laser interferometry and micro-Newton thrusters.  But instead of a separation of 5 million km as in the three-spacecraft LISA mission, LISA Pathfinder will use test masses only 30cm apart and placed on a single spacecraft.

Armed with this cosmic yardstick, sky explorers can determine what the universe is made of and how fast it is expanding by observing many supernovae at different distances. First of all, the data from Pantheon+ confirm the previous cosmological model with unprecedented accuracy: The matter of which stars, planets and also we humans are made makes up only a tiny proportion of about five percent of the cosmos. The universe is dominated by dark matter and dark energy.

The Dark Matter contributes about 29 percent to the cosmos and ensures that galaxies and galaxy clusters are held together by gravity – the visible normal matter alone would not be sufficient for this. Without dark matter, stars, planets and also no life would never have arisen in the cosmos. The researchers suspect that dark matter consists of previously unknown particles. But all attempts to track down such particles have so far been unsuccessful.

Cosmic expansion accelerates

Dark energy is even more mysterious. The universe was created 13.8 billion years ago with the Big Bang and has been expanding ever since. This cosmic expansion should be slowed down slowly by the attraction of matter. In fact, the opposite is the case: it’s accelerating. The researchers see a kind of inner energy of the room as the cause. Pantheon+ data now shows that this dark energy has probably not changed throughout cosmic history, it is constant.

Pantheon+’s answer to the question of how fast the universe is expanding today is explosive. Astronomers describe the rate of expansion using the Hubble constant, named after Edwin Hubble, the discoverer of cosmic expansion. Pantheon+ delivers a value of 73.4 for the Hubble constant with an uncertainty of only 1.3 percent.

also read

"James Webb"-Image of space released on July 12, 2022

However, there is a second, independent method to determine the Hubble constant. It is based on a detailed study of the cosmic background radiation – a kind of radiation echo from the Big Bang – and gives a value of 67.4 with an uncertainty of 0.7 percent. The numerical values ​​indicate by how many kilometers per second the distance between two objects that are 3.26 million light years – one megaparsec – apart increases.

The difference between the two values ​​is called the Hubble voltage. So far, researchers have still hoped that the difference would simply turn out to be a statistical error. But with the new data from Pantheon+, the probability of this has dropped to well below one ten-thousandth of a percent.

More about astronomy and space travel

“We had hoped to find a possible solution to the problem with our data,” says co-author Dillon Brout from the Harvard Smithsonian Center for Astrophysics in the USA. “Instead, we have to discard many remaining explanations and the differences are more serious than ever.” The Hubble voltage indicates a new physics in the young cosmos – and there are now many theoretical considerations. “But these theories have yet to withstand the scientific process,” says Brout – so they can be verified by further observational data.

You can listen to our WELT podcasts here

In order to display embedded content, your revocable consent to the transmission and processing of personal data is required, since the providers of the embedded content as third-party providers require this consent [In diesem Zusammenhang können auch Nutzungsprofile (u.a. auf Basis von Cookie-IDs) gebildet und angereichert werden, auch außerhalb des EWR]. By setting the switch to “on”, you agree to this (which can be revoked at any time). This also includes your consent to the transfer of certain personal data to third countries, including the USA, in accordance with Art. 49 (1) (a) GDPR. You can find more information about this. You can withdraw your consent at any time via the switch and via privacy at the bottom of the page.

“Aha! Ten minutes of everyday knowledge” is WELT’s knowledge podcast. Every Tuesday and Thursday we answer everyday questions from the field of science. Subscribe to the podcast at Spotify, Apple Podcasts, deezer, Amazon Music or directly via RSS feed.

See more here

See also  ″Artemis I″ to pave way for future lunar settlement | Knowledge & Environment | DW

Leave a Reply

Your email address will not be published. Required fields are marked *