FutureStarr

A Future in the Stars

A Future in the Stars

Future in the Stars

Twelve ancient constellations are sharply defined today, and our knowledge of the stars is in part due to their names. The ancient Greeks recognized the first few in the constellation Leo. But the Western constellations are far from stable and are constantly changing. In fact, some of the older constellations have already faded from the sky.

Future

This relative motion of stars across the sky is known as proper motion. It is this motion that causes the stars to move over thousands of years. The constellations we see today are only temporary. They were not the constellations of our long-ago ancestors, and they will not be the constellations of our far-future descendants. Since Halley’s first observations, astronomers have measured the proper motion of thousands of stars. But in the past couple decades that number as grown exponentially. In 2000, the Hipparcos catalog was released. Based on data gathered by the Hipparcos spacecraft, it contains the positions and proper motions of more than 100,000 stars. This year initial data from the Gaia spacecraft was released, containing the position and proper motion of more than 2 million stars. Since stars basically move freely through space, we can use their proper motions to predict where they will be in the future. You can see this in the video above, which plots the proper motions of Gaia’s 2 million stars. It gives us a glimpse of how future generations might see the night sky.

Then, in their 1999 book The Five Ages of the Universe, the astrophysicists Fred Adams and Gregory Laughlin divided the past and future history of an expanding universe into five eras. The first, the Primordial Era, is the time in the past just after the Big Bang when stars had not yet formed. The second, the Stelliferous Era, includes the present day and all of the stars and galaxies now seen. It is the time during which stars form from collapsing clouds of gas. In the subsequent Degenerate Era, the stars will have burnt out, leaving all stellar-mass objects as stellar remnants—white dwarfs, neutron stars, and black holes. In the Black Hole Era, white dwarfs, neutron stars, and other smaller astronomical objects have been destroyed by proton decay, leaving only black holes. Finally, in the Dark Era, even black holes have disappeared, leaving only a dilute gas of photons and leptons. (Source: en.wikipedia.org)

 

 

Related Articles