StarDate

Messier 79


Listen Later

The star cluster M79 is messy. It’s shedding some of its stars, creating a “tail.” Over the eons, in fact, the cluster might have lost most of the stars it was born with.

Messier 79 is a globular cluster – a ball-shaped family of about 150,000 stars. The cluster is more than 11 billion years old, so its stars are among the oldest in the entire Milky Way Galaxy.

There’s a trail of stars behind the cluster. The stars probably were stripped away by the gravity of the rest of the galaxy – especially its dense core.

Today, M79 is about 42,000 light-years from the Milky Way’s heart. But its orbit might bring it within just a few hundred light-years of the center. At that distance, the gravity of the galaxy’s core overpowers the gravity of the cluster. So stars in M79’s outskirts are pulled away. Eventually, they move away, and follow their own paths across the galaxy.

Some simulations have suggested that M79 has lost up to 85 percent of its original population of a million stars or so. And every future passage through the heart of the galaxy will pull away more stars – leaving only a glimmer of M79’s original glory.

M79 is in Lepus, the hare. The constellation is close to the lower right of bright Orion, in the southeast at nightfall. M79 is below the outline of the rabbit. You need binoculars to pick it out.

Script by Damond Benningfield

...more
View all episodesView all episodes
Download on the App Store

StarDateBy Billy Henry

  • 4.6
  • 4.6
  • 4.6
  • 4.6
  • 4.6

4.6

251 ratings


More shows like StarDate

View all
Radiolab by WNYC Studios

Radiolab

43,837 Listeners

The 365 Days of Astronomy by 365DaysOfAstronomy.org

The 365 Days of Astronomy

350 Listeners

Planetary Radio: Space Exploration, Astronomy and Science by The Planetary Society

Planetary Radio: Space Exploration, Astronomy and Science

1,356 Listeners

SpaceTime with Stuart Gary by Stuart Gary

SpaceTime with Stuart Gary

321 Listeners

BirdNote Daily by BirdNote

BirdNote Daily

1,259 Listeners

Ask a Spaceman! by Paul M. Sutter

Ask a Spaceman!

838 Listeners

Astronomy Cast by Fraser Cain and Dr. Pamela Gay

Astronomy Cast

2,882 Listeners

Universe Today Podcast by Fraser Cain

Universe Today Podcast

566 Listeners

Space Nuts: Astronomy Insights & Cosmic Discoveries by Professor Fred Watson and Andrew Dunkley

Space Nuts: Astronomy Insights & Cosmic Discoveries

231 Listeners

Science Friday by Science Friday and WNYC Studios

Science Friday

6,467 Listeners

Short Wave by NPR

Short Wave

6,592 Listeners

The Supermassive Podcast by The Royal Astronomical Society

The Supermassive Podcast

323 Listeners

NASA's Curious Universe by National Aeronautics and Space Administration (NASA)

NASA's Curious Universe

883 Listeners

Why This Universe? by Dan Hooper, Shalma Wegsman

Why This Universe?

384 Listeners

Crash Course Pods: The Universe by Crash Course Pods, Complexly

Crash Course Pods: The Universe

572 Listeners