Astronomers have developed a new way to measure cosmic distances by listening to the frequencies of the “music” played by vibrating stars that collectively act as a vast orchestra of different cosmic instruments.
Results can help European Space Agency (ESA) The Gaia satellite measures the positions of about two billion stars, as well as the distances between them Land And movements while building an accurate three-dimensional map of the place milky way.
Scientists usually use a process called… the view, the apparent shift in the position of an object when viewed from two different locations, to measure the distance to different stars. They then measure the angles of the star itself, using Gaia’s position spaceAn attempt at triangulation. But the problem is that the further away the star is, the smaller the apparent displacement of the parallax. The smaller the parallax offset, the more likely subtle systematic errors are to creep in, which can lead to bias in the measurements.
A team of researchers, including scientists from the Federal Institute of Technology in Lausanne (EPFL) and the University of Bologna, is working to eliminate these errors. In short, they have developed the most accurate feedback ever for over 12,000 vibrations Red giant stars.
Related: New data from the Gaia telescope reveals a ‘gold mine’ of more than 500,000 undiscovered stars and much more.
“We measured Gaia’s biases by comparing its reported parallaxes Satellites With the view of the same stars “We identified using astroseismology,” said Sania Khan, a researcher in the Candlestick and Standard Distances group at EPFL who led the recent work. He said in a statement.
What shakes Gaia?
The team’s analysis of stellar oscillations is called “astroseismology,” and is similar to how geologists investigate the Earth’s structure by tracking patterns in Earthquakes.
Khan and his colleagues used the vibrations and oscillations of star samples, which can be seen as small differences in light intensity, by converting them into sound waves. In return, they were able to discover a group of associated sound frequencies. It was then possible to convert these stellar sound frequencies into distance measurements.
“The frequency spectrum allows us to determine how far away the star is, enabling us to obtain asteroid parallax variations,” Khan said. “In our study, we listened to the ‘music’ of a large number of stars – some as many as 15,000 stars.” Light year far!”
The range of sounds also told the team more about the stars in their sample, which helped them pick out the cosmic instruments in this celestial orchestra.
“By analyzing the frequency spectrum of stellar oscillations, we can estimate the size of a star, just as you can determine the size of a musical instrument by the type of sound it makes — think of the difference in pitch between a violin and a cello,” said Andrea Meglio, one of the study’s authors and a scientist in the University of California’s Department of Physics and Astronomy. Bologna, in the statement.
Once the team used this method to calculate a star’s size, it became possible to calculate its brightness as well. This brightness can also be compared to how bright a star shines for us as we stand here on Earth. This information was combined with observations showing the stars’ temperatures and chemical composition to calculate the final distance.
This calculated distance was then used to determine parallax, which could be checked against the parallax obtained by Gaia during data collection. It was a wide-ranging examination of the measurement accuracy of the ESA mission.
“Gaia has increased by a factor of 10,000 the number of stars whose eclipses are measured thanks to the huge increase in resolution compared to its predecessor, ESA’s Hipparcos mission,” said Richard Anderson, head of the Candles and Standard Distances Research Group at EPFL. statement. “Astroseismology is the only way we can verify the accuracy of Gaia’s parallax across the entire sky – that is, for low- and high-density stars.”
Just like the stars you study, the future could be bright for an astronomy-based method of measuring distance.
“Upcoming space missions such as TESS and PLATO aim to detect and survey Exoplanets “It will use astroseismology and provide the required data sets across increasingly large regions of the sky,” Khan concluded. “Methods like ours will therefore play a crucial role in improving measurements of the Gaia landscape, which will help us determine our place in Universe And take advantage of the large number of subfields of Astronomy And Astrophysics“.
The team’s research was published in September in the journal Astronomy and astrophysics.