FEATURED IMAGE: 17 Oct 2019, 18:04 UTC | The Clumpy and Lumpy Death of a Star 20 October 2019, 10:31:30UTC RSS RSS | About | Contact | Site Map
Home » News & Blogs » When it comes to making stars, galactic gas tanks are nowhere near full
Bookmark and Share
Bad Astronomy

When it comes to making stars, galactic gas tanks are nowhere near full

7 Aug 2019, 13:00 UTC
When it comes to making stars, galactic gas tanks are nowhere near full
(200 words excerpt, click title or image to see full post)

Stars, like people, are born, live out their lives, and eventually die. We understand quite a bit about all three of these phases (for stars; people are less predictable), but there is still a lot we don't know.

For example, stars are born in clouds of gas called nebulae. But there are lots of different kinds of gas clouds; stars are born where the gas is dense enough that the gravity of the gas can overcome its internal pressure, collapsing it. Many nebulae are huge, dozens of light years across or more, with fairly low-density gas in them. Only a fraction of that gas is dense enough to make stars.

Assigning a number to that fraction is important. When we look at distance galaxies we can measure the total amount of gas in them, but it can be extremely difficult to know how much of that gas will lead to star formation. We can generally measure star formation in those galaxies too (it's a long chain of logic, but in a nutshell when lots of stars are born, some (small) known fraction of them are high mass stars, and these blast out ultraviolet radiation that can be measured in a ...

Latest Vodcast

Latest Podcast

Advertise PTTU

NASA Picture of the Day

Astronomy Picture of the Day

astronomy_pod