parkmodelsandcabins.com

# New Insights into the Milky Way's Mass: Hubble and Gaia Collaboration

Written on

Chapter 1: Measuring the Milky Way's Mass

For many years, astronomers have been intrigued by the mass of our Milky Way Galaxy, with current estimates ranging from 500 billion to three trillion solar masses. Recent collaborations between the Hubble Space Telescope (HST) and the European Space Agency’s Gaia observatory have led to a more refined estimate of approximately 1.5 trillion solar masses.

The elusive dark matter constitutes a significant portion of the galaxy's total mass but remains invisible; its gravitational effects are critical in determining the galaxy's dynamics. The discrepancies in earlier mass estimates largely stemmed from varying models of dark matter distribution within the Milky Way.

To derive this new measurement, researchers analyzed globular clusters—small groups of stars orbiting the Milky Way. These clusters, held in place by gravity, have velocities that can indicate the mass of their host galaxy; the faster these clusters move, the more massive the galaxy. However, precise velocity measurements of these clusters were only achievable after the launch of Hubble and Gaia.

“Previous measurements primarily focused on the speed of a cluster as it approaches or recedes from Earth, which is merely the velocity along our line of sight. Our approach allowed us to also assess the lateral motion of these clusters, enabling the calculation of total velocity and, subsequently, the galactic mass,” explained N. Wyn Evans from the University of Cambridge.

Visualization of globular clusters around the Milky Way

This illustration depicts the distribution of globular clusters surrounding the Milky Way. Image credit: ESA/Hubble, NASA, L. Calçada

The Milky Way boasts an estimated 200 billion stars and contains a supermassive black hole at its core, which has a mass equivalent to four million suns. Additionally, the galaxy is enveloped by extensive dark matter, which, while not emitting radiation, is confirmed through its gravitational influence.

“We aim to determine the Milky Way's mass with greater accuracy to contextualize it within cosmology and compare it against galaxy simulations in the evolving universe. The uncertainty surrounding the Milky Way's mass complicates numerous cosmological inquiries,” remarked Roeland van der Marel from the Space Telescope Science Institute (STScI).

Launched in 2013, the Gaia satellite embarked on a mission to create a three-dimensional map of over one billion stars within our galaxy. Its data, combined with Hubble's observations, enabled researchers to analyze the motion of globular clusters to ascertain the mass of the Milky Way. The study utilized Hubble data from 12 clusters located up to 130,000 light years from Earth, and integrated it with Gaia's observations of 34 clusters as far as 65,000 light years away.

Hubble's view of globular cluster NGC 362

The globular cluster NGC 362 captured by the Hubble Space Telescope, one of approximately 150 similar structures orbiting the Milky Way. Image credit: ESA/Hubble/NASA

Globular clusters are home to some of the Universe's oldest stars, formed during the initial stellar events in the cosmos. The mass identified in this recent study pertains to the region within 129,000 light years from the galactic center. Other galaxies display a vast range of masses, from one billion to 30 trillion solar masses. Dark matter exists not only around galaxies but also in the voids between them, influencing the evolution and dynamics of galaxies across the cosmos.

Chapter 2: Understanding Dark Matter's Role

In the video "How much does the Milky Way weigh? - New result from Hubble and Gaia," experts discuss the latest findings regarding the mass of our galaxy, derived from the collaboration of Hubble and Gaia.

The second video, "The Merger History of the Milky Way – What Gaia Revealed with Eva Grebel," explores how Gaia’s data has shed light on the Milky Way's formation and mergers, enhancing our understanding of its structure and mass.

Share the page:

Twitter Facebook Reddit LinkIn

-----------------------

Recent Post:

Twitter Explores $4 Billion Acquisition of Clubhouse

Twitter considered acquiring Clubhouse for $4 billion. Talks have ceased, and the platform looks to secure funding at the same valuation.

Maximize Your Marketing Impact with These Simple Fixes

Discover three straightforward strategies to enhance your marketing effectiveness and outpace your competitors.

Creating an Effective Blue Ocean Strategy for Your Business

Learn how to develop a Blue Ocean Strategy to establish a unique market position and boost customer loyalty.