StarDate

Escapees


Listen Later

A small star with a planetary companion appears to be making a high-speed exit from the center of the Milky Way – perhaps fast enough to escape the galaxy entirely.

The system is more than 24,000 light-years away, in Sagittarius. It appears to contain a red-dwarf star – a cool, faint ember about 20 percent the mass of the Sun. It’s accompanied by a “super-Neptune” – a planet about 30 times the mass of Earth. They’re separated by less than the distance from Earth to the Sun.

What makes the system especially interesting is its high speed – at least 1.2 million miles per hour. That’s not fast enough to leave the Milky Way behind. But it could be moving a good bit faster.

The system might have started as a member of a binary – two stars bound by gravity. The stars passed too close to the monster black hole in the galaxy’s heart. The black hole grabbed the other star, and gave the escapee a giant kick. On the other hand, the kick could have come from an encounter with a smaller black hole in the Milky Way’s crowded center.

How the star maintained its grip on the planet is a key question. But the planet must have been in a tight orbit to avoid being yanked away.

Researchers were scheduled to take some follow-up observations this month. That might reveal whether the system really is a star and planet on a high-speed ride through the galaxy.

We’ll talk about another possible escapee tomorrow.

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

44,012 Listeners

The 365 Days of Astronomy by 365DaysOfAstronomy.org

The 365 Days of Astronomy

351 Listeners

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

Planetary Radio: Space Exploration, Astronomy and Science

1,357 Listeners

SpaceTime: Your Guide to Space & Astronomy by Stuart Gary

SpaceTime: Your Guide to Space & Astronomy

298 Listeners

BirdNote Daily by BirdNote

BirdNote Daily

1,222 Listeners

Ask a Spaceman! by Paul M. Sutter

Ask a Spaceman!

833 Listeners

Astronomy Cast by Fraser Cain and Dr. Pamela Gay

Astronomy Cast

2,875 Listeners

Universe Today Podcast by Fraser Cain

Universe Today Podcast

560 Listeners

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

Space Nuts: Astronomy Insights & Cosmic Discoveries

230 Listeners

Science Friday by Science Friday and WNYC Studios

Science Friday

6,347 Listeners

Short Wave by NPR

Short Wave

6,371 Listeners

The Supermassive Podcast by The Royal Astronomical Society

The Supermassive Podcast

318 Listeners

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

NASA's Curious Universe

853 Listeners

Why This Universe? by Dan Hooper, Shalma Wegsman

Why This Universe?

390 Listeners

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

Crash Course Pods: The Universe

508 Listeners