The mass of the Milky Way Galaxy is a question that has long puzzled astronomers and astrophysicists. Estimates ranged from between 500 billion to three trillion times the mass of our Sun. A new study looked at globular clusters, groupings of a million or so stars surrounding the Milky Way. By measuring the velocity at which they circled our galaxy, as measured by the Hubble Space Telescope and the Gaia Telescope, astronomers determined the Milky Way has a mass around one-and-a-half trillion times as great as our Sun.Read More Hubble and Gaia Team Up to Measure the Mass of the Milky Way
Astronomers have long theorized that planetary systems can be affected by stars passing near solar systems. However, direct evidence of this has never been seen, until now.
Sitting 300 light years from Earth, the star HD 106906 is accompanied by a planet 11 times the size of Jupiter, orbiting the pair of binary stars 738 times further away than the distance between the Earth and the Sun. Computer simulations show that roughly 12 million years ago, another pair of stars passed the system, altering the orbit of this giant world, pulling it far from its stellar companions. Had the encounter not taken place, this world would have crashed into the stars around which it orbits.
A river of 4,000 stars has been detected just 330 light years from the Sun. This grouping is one billion years old, and has circled the outer edge of the Milky Way Galaxy four times since its formation. Astronomers found the formation using the Gaia space telescope, operated by the European Space Agency.Read More Billion-Year-Old River of Stars Seen Flowing Near the Sun