Gaia Space Mission

Why in the News?

Recently, the third dataset released by the European Space Agency’s Gaia mission has revealed the surprise phenomena of ‘starquakes’.

Key Points:

Gaia Space Mission:

• Gaia is an astronomical observatory mission launched in 2013 from Kourou, French Guiana

• Launching Agency:  European Space Agency (ESA)

• Objective: To create the most accurate and complete 3D map of the Milky Way by surveying 1% or one billion of the galaxy’s 100 billion stars

• In the Gaia mission the following three techniques are used for observation: Astrometry, Photometry and Spectroscopy

Key Findings of Third Dataset:

• ‘Starquakes’: These are similar to earthquake-like movements but on the surface of stars
• It contains improved information on nearly two billion celestial objects-including stars in the Milky Way, objects outside the galaxy and those inside our solar system
• Milky Way: It contains the largest-ever three-dimensional map of stars in the Milky Way
• The map shows the chemical compositions as well as past and future movements of stars
• Starquakes: One of the most surprising discoveries was that of more than 100,000 ‘starquakes’- which can be likened to tsunamis or massive vibrations on the surface of stars that can change their shape
• Quasars: The new Gaia data has revealed the measurements of over a million confirmed quasars
• The discovery of new quasars is significant as it helps to measure the most distant stretches of our universe
• Position of Stars: The data shows chemical components, colours, brightness, velocity, temperatures, and positions of millions of stars
• According to the ESA, astronomers hope to use the data to understand better how stars are born and die, and how the Milky Way evolved over billions of years
• Binary Systems: The new data has revealed the position, distance, orbits, and masses of over 8,00,000 binary star systems

Key Terms

Astrometry

•  Astrometry is the science of measuring the movement and position of stars within the plane of the sky, photometry studies the colour, brightness and other derived properties of stars

Spectroscopy 

• Spectroscopy measures the radial velocity or the movement of stars towards or away from us by studying stellar spectra or the fingerprints of stars

Quasars 

• Quasars are extraordinarily active and bright cores of galaxies powered by supermassive black holes
• These are the most luminous objects in the universe and are visible along its distant edges

Binary Star Systems:

• These are two stars that orbit each other around a shared centre

Significance of Gaia Mission:

• Understanding Galaxy Evolution: This information allows astronomers to reconstruct the galaxy’s past and future evolution over billions of years
• Tracing the Location of origin: The new set shows the radial velocity of 33 million stars, i.e. how fast are these stars moving towards, or away from us
• This can not only help scientists figure out the trajectory of the stars, but also their location of origin
• Astronomers hope to use the data to understand better how stars are born and die, and how the Milky Way evolved over billions of years