from the cut-them-in-half-and-count-the-rings dept.
One of the long-standing difficulties in astrophysics has been a way to accurately determine the age of a star. Brand new stars are obvious from their location in or near "star nurseries" of interstellar gas and dust, and "adult" stars can be roughly characterized through various methods, including a calculation based on their mass and luminosity. Unfortunately, these methods are approximations at best. Researchers at KU Leuven's Institute for Astronomy have now discovered a way to distinguish young stars from older ones by measuring the acoustic waves that they emit using ultrasound technology.
The result of the accretion of shrinking clouds of gas and dust particles, a star evolves from "newborn" to "adolescent" as growing gravitational forces cause it to contract. As these forces continue, the star becomes smaller, denser, and hotter until the core temperature is great enough to trigger thermonuclear fusion. Once this stage has been reached, and the star has stabilized in its size and fusion energy production over a very long period of time, it is classed as an "adult" and generally remains in this state for many billions of years. As a general rule, as an adult star ages it becomes brighter. This means it is possible to approximate the ages of these stars using a calculation based on their mass and luminosity. This method works particularly well for stellar objects in their main sequence, where they are stable, adult stars falling within a particular range of mass, color, and luminosity.
(Score: 0) by Anonymous Coward on Tuesday July 08 2014, @07:27AM
I like how the entire second paragraph is just an elaboration on calculating star age based on mass and luminosity, and not about sound waves as the title and first paragraph suggested.
Great summary guys!
(Score: 2) by q.kontinuum on Tuesday July 08 2014, @07:42AM
I was thinking the same, especially since the first paragraph points out how these estimates are "approximations at best", while the unexplained sound method is supposed to be superior.
Registered IRC nick on chat.soylentnews.org: qkontinuum
(Score: 2) by aristarchus on Tuesday July 08 2014, @08:13AM
Abstract refers to asteroseismology, not sound waves, which would, I believe, require a medium between us and said star?
(Score: 1) by cyrano on Tuesday July 08 2014, @02:23PM
It's sound allright. It's only picked up on earth through light ;-)
The quieter you become, the more you are able to hear. - Kali [kali.org]
(Score: 2) by aristarchus on Tuesday July 08 2014, @10:00PM
Maybe it is the analogy that is throwing everybody off:
[from the Gizmag article]
To be picky, (which I would never do), it is detection of vibrations by means of light, so it is not sound, or not sound as we know it, and the ultrasound thing is an artifact of the analogy to studying very young (in utero) humans. This demands a re0visit of the old chestnut, "If a star is born in a gaseous nebula and nobody sees it, does it make a sound?"
(Score: 1) by cyrano on Wednesday July 09 2014, @02:37PM
Optical microphones exist. Don't they record sound?
The quieter you become, the more you are able to hear. - Kali [kali.org]
(Score: 2) by aristarchus on Wednesday July 09 2014, @11:07PM
And no doubt there are sonic cameras, as well! Nope, optical microphones are recording a vibration of light, that is somehow related to or caused by a vibration in a medium, such as gas, which some would call "sound", but is not sound until it is converted.
(Score: 2) by Tork on Tuesday July 08 2014, @08:40AM
🏳️🌈 Proud Ally 🏳️🌈
(Score: 3, Informative) by wonkey_monkey on Tuesday July 08 2014, @10:08AM
It's the first two paragraphs of this article [gizmag.com].
systemd is Roko's Basilisk
(Score: 4, Informative) by wonkey_monkey on Tuesday July 08 2014, @10:10AM
As a previous commenter has pointed out, the summary barely touches on the acoustic method, with the second paragraph solely talking about established methods of dating stars.
The reason for this is that the two paragraphs have been copied directly from this Gizmag article [gizmag.com].
If you're not going to write your own summary, you could at least credit the people who did the work for you with a link.
systemd is Roko's Basilisk
(Score: 3, Insightful) by AnonTechie on Tuesday July 08 2014, @10:56AM
My mistake ... sorry !
Albert Einstein - "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
(Score: 0) by Anonymous Coward on Tuesday July 08 2014, @02:10PM
Why are you submitting stories that apparently you either have not read or do not understand?
(Score: 2) by AnonTechie on Tuesday July 08 2014, @06:17PM
Your comment hurts .. I forgot to include the link ...
Albert Einstein - "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
(Score: 2) by aristarchus on Wednesday July 09 2014, @12:01AM
Leave AnonTechie alone!!!!!!!
(Score: 2) by redneckmother on Tuesday July 08 2014, @04:31PM
I'm confused. Is this "in space, no one can hear you scream" or "music of the spheres"?
Mas cerveza por favor.