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Tag: Milky Way

  • Massive Black Hole Found in Milky Way’s Binary System

    Massive Black Hole Found in Milky Way’s Binary System

    Astronomers have found a really big black hole in our Milky Way galaxy. This huge black hole is special because it’s in a pair of stars. The discovery is exciting and surprises scientists. It helps us learn more about black holes.

    Milky Way

    When a very big star in space burns out, it explodes in a big event called a supernova. After the explosion, its center collapses into a tiny, super dense point called a black hole. Black holes have strong gravity, so strong that not even light can escape them. They’re like invisible giants in space.

    Finding black holes is hard because we can’t see them directly. But the European Space Agency’s Gaia spacecraft helps. It maps stars in our galaxy with incredible detail. Scientists use Gaia’s data to study stars and find hidden black holes.

    A team of scientists, including some from Tel Aviv University, looked at Gaia’s data. They focused on pairs of stars called binary systems. In one of these pairs, they noticed something strange. One star moved like it was orbiting something invisible. That something turned out to be a massive black hole.

    This black hole is super heavy, 33 times heavier than our Sun. It’s the biggest black hole found in a binary system in our galaxy. The system is called Gaia BH3. It’s 1,500 light-years away from us.

    The two stars in Gaia BH3 are very different. One is a normal star, while the other is the black hole. The normal star is very old, maybe more than 10 billion years old. This age gap between the star and the black hole is a puzzle for scientists.

    Finding Gaia BH3 was tough. Black holes are hard to spot. But Gaia’s discoveries show there might be many more out there. Scientists are excited about what they might find next. This discovery could change how we think about black holes in our galaxy.

  • Gaia’s Revelation: Uncovering the Earliest Building Blocks of the Milky Way

    Gaia’s Revelation: Uncovering the Earliest Building Blocks of the Milky Way

    Astronomers have identified what might be two of the Milky Way’s earliest building blocks, dubbed “Shakti” and “Shiva,” suggesting they merged with the early Milky Way over 12 to 13 billion years ago, contributing to its initial formation. Combining data from ESA’s Gaia mission with measurements from the SDSS survey, astronomers made this groundbreaking discovery, akin to archeologists uncovering traces of an ancient settlement that evolved into a modern city.

    Milky Way

    The Milky Way’s history involves the merging of smaller galaxies, forming substantial building blocks. Researchers Khyati Malhan and Hans-Walter Rix from the Max Planck Institute for Astronomy identified two potential early building blocks, Shakti and Shiva, remnants of galaxies that merged with the Milky Way billions of years ago. By analyzing Gaia and SDSS data, they found these fragments, akin to discovering the roots of a present-day city.

    When galaxies merge, they bring along their hydrogen gas clouds, leading to the formation of new stars. Stars from merging galaxies mingle, contributing to the stellar population of the newly formed galaxy. Despite the challenge of identifying stars’ origins post-merger, certain physical properties like energy and angular momentum offer clues to trace their ancestry. Stars with similar energy and angular momentum likely originated from the same pre-merger galaxy.

    Lower metallicity indicates older stars. Thus, stars with low metal content, known as “metal-poor” stars, likely formed early in the galaxy’s history. This method, along with Gaia’s extensive data set launched in 2013, enables astronomers to excavate the Milky Way’s ancient past.

    Malhan and Rix used Gaia data combined with stellar spectra from the Sloan Digital Sky Survey to identify Shakti and Shiva. They observed groups of metal-poor stars with specific energy and angular momentum combinations, indicative of stars originating from separate merging galaxies. Named after Hindu deities, Shakti and Shiva show high angular momentum and low metallicity, suggesting they could be among the Milky Way’s earliest ancestors.

    These findings expand our understanding of the Milky Way’s formation. Shakti and Shiva, possibly the first additions to the Milky Way’s core, played a crucial role in its growth into a large galaxy. This discovery underscores the importance of data-driven astronomical research and its role in unraveling the mysteries of the universe.