MessageToEagle.com

Stars In The Milky Way Move In Mysterious Ways

8 February, 2012

MessageToEagle.com - Appearently we still have a lot to learn about the stars in the Milky Way.

Something strange has been noticed about the stars in our galaxy.

Rather than moving in circles around the center of the Milky Way, all the stars in our Galaxy are travelling along different paths, moving away from the Galactic center.

This strange behavior may be due to perturbation caused by the central bar and spiral arms of our Galaxy, forcing stars to leave their normal circular course and take an outward path.

Most galaxies, including our own Milky Way, are spiral-shaped and stars are distributed in a thin disk rotating around the galactic center, with areas divided into spiral arms or elliptical regions such as the central bar.

Due to gravity, the spiral arms move through the disk in the form of density waves.

For over twenty years, scientists believed that the potential impact of these density waves on stellar velocities in the Milky Way was insignificant in comparison with the circular motion of the stars in the galactic disk.

This belief has now been blatantly proved wrong by an international team including several researchers from the Strasbourg Astronomical Observatory: near the Earth, stars move towards the exterior of the Galaxy at an average speed of around 10 kilometers per second, which is considerably faster than previously thought.

To reach this conclusion, the team systematically analyzed the velocities of over two hundred thousand stars located within a radius of a little over six thousand light years around the Sun.

Using data from the major star survey RAVE (RAdial Velocity Experiment)(1) collected since 2003 by the Australian Astronomical Observatory's Schmidt telescope, they were able to measure for the first time the radial velocities of hundreds of thousands of stars and determine whether they were moving towards or away from us.

© Gal Matijevic, Ljubljana University

The Sun (in yellow) is located 25 000 light years from the center of the Milky Way. The stars whose velocities were measured by RAVE are shown in red. The arrows show the outward motion observed by the researchers at the Strasbourg Observatory and their colleagues.

The researchers were thus able to ascertain that the average speed of stars towards the exterior of the Galaxy increases with their distance from the Sun in the direction of the Galactic center, reaching 10 kilometers per second at a distance of 6 000 light years from us (in other words, 19 000 light years from the Galactic center).


Credit: RAVE

This result was completely unexpected and all the more surprising as it appeared to mainly affect old stars, several billion years old. Until now, it was thought that the spiral arms mostly affected the dynamics of young stars (only a few tens-of-million-years old).

However, theoretical study of the combined effect of the spiral arms and the central bar, both within and outside the plane of the Galaxy, could explain the strange distortions of stellar motion observed by the astronomers in the RAVE team.

This research has been conducted by Arnaud Siebert and Benoit Famaey, astronomers at the Strasbourg Astronomical Observatory (CNRS/Université de Strasbourg), and by their colleagues in other countries.

RAVE (RAdial Velocity Experiment) is a multi-fiber spectroscopic astronomical survey of stars in the Milky Way using the 1.2-m UK Schmidt Telescope of the Anglo-Australian Observatory (AAO). The RAVE collaboration consists of researchers from over 20 institutions around the world and is coordinated by the Leibniz-Institut für Astrophysik Potsdam.

See also: Monster Star Thousand Times Bigger Than Our Sun Could Soon Explode
Star Changes Into An Incredible Diamond Planet

Follow MessageToEagle.com for the latest news on Facebook and Twitter !

Don't Miss Our Stories! Get Our Daily Email Newsletter

Enter your email address:


Once you have confirmed your email address, you will be subscribed to the newsletter.

Recommend this article:

Subscribe To Our News!

Grab the latest RSS feeds right to your reader, desktop or mobile phone.

Subscribe to RSS headline updates from:
Powered by FeedBurner

Go to - MAIN PAGE

Copyright @ MessageToEagle.com All rights reserved.
Go to - MAIN PAGE

Other Popular Articles

Astrophysicist Resolves Paradox With Radio Millisecond Pulsars
Celestial objects known as pulsars are still full of secrets. It is takes time and many efforts to learn all their secrets. Previous studies reached the paradoxical conclusion that some millisecond pulsars are even older than the universe itself. It was time to resolve this paradox.


Mysterious Signal From Outer Space - Is Someone Trying To Contact Us?
A mysterious signal coming from a region of space between the constellations Pisces and Aries has been picked up on three different occasions by the Arecibo radio telescope in Puerto Rico...


Astronomical Mystery: Giant Alien Planet Orbiting Three Suns
Binary stars are well-known and even trinary systems may be common but most of them are crowded together and thus, difficult to find and study. Additionally, it has long been considered they are inhospitable to planets...


Unusual Sounds From Space Reported Worldwide - What Are They?
For almost a year now people from different countries have reported hearing strange sound from the sky. Now scientists propose that what people are hearing is only a small fraction of the actual power of these sounds! What are these sounds? What is causing them? Are they in anyway related to our Sun and the biggest solar flares, do they come from Earth's inner core or can they be attributed to an unknown an astronomical phenomenon? Are they in anyway dangerous to our planet?


Unknown Force "Intelligently" Put Together Miranda Moon - with video
What could melt this moon in this extremely cold region of the solar system? Voyager 2 passed Miranda’s strange world at a distance of only 3,000 kilometers (1,800 miles) and sent back to Earth very detailed images of its "tortured" surface. Nothing like them has been seen anywhere else in the solar system! Did a type III civilization conduct some "experiments" on Miranda?


Mysterious Jelly-Like Blue Spheres That Fell From The Sky Are Not Of Meteorological Origin
Residents in United Kingdom were baffled when they suddenly saw strange jelly-like blue spheres falling from they sky. Steve Hornsby, a former aircraft engineer from Bournemouth found these strange spheres in his garden, last Thursday. "The sky went a really dark yellow colour."

W3Counter