Featured Research

from universities, journals, and other organizations

Spinstars: First polluters of the universe? Imprints of fast rotating massive stars in Milky Way's bulge

Date:
April 30, 2011
Source:
Leibniz-Institut für Astrophysik Potsdam (AIP)
Summary:
From the analysis of the chemical composition of some of the oldest stars in our galaxy, an international team of astronomers presents new clues on the nature of the first stellar generations in our universe.

Simulation of the formation of the first stars showing fast rotation.
Credit: A. Stacy, University of Texas / Figure adapted from Stacy et al, 2011, MNRAS 413,1, 543

From the analysis of the chemical composition of some of the oldest stars in our Galaxy, an international team of astronomers led by Cristina Chiappini from the Leibniz-Institut für Astrophysik Potsdam (AIP) and the Instituto Nazionale di Astrofisica (INAF) presents new clues on the nature of the first stellar generations in our Universe.

"We think that the first generations of massive stars were very fast rotators -- that's why we called them spinstars," explains Chiappini. Their findings will be published in a Nature article on April 28, 2011.

Massive stars live fast and furious, and hence the first generations of massive stars in the Universe are already dead. However, their chemical imprints, like fingerprints, can still be found today in the oldest stars in our Galaxy. These fossil records are thus the witnesses of the nature of the first stellar generations to pollute our Universe. "It is like if we tried to reveal the character of a cook from the taste of his dishes," says Prof. Georges Meynet, from the Geneva University.

How were these first stars? Were they different from the stars we observe today? Soon after the Big Bang, the composition of the Universe was much simpler than at present as it was made of essentially only hydrogen and helium. The chemical enrichment of the Universe with other elements had to wait around 300 million years until the fireworks started with the death of the first generations of massive stars, polluting the primordial gas with new chemical elements, which were later incorporated in the next generations of stars.

Using data from ESO's Very Large Telescope (VLT), the astronomers reanalyzed spectra of a group of very old stars in the Galactic Bulge. These stars are so old that only very massive, short-living stars with masses larger than around ten times the mass of our Sun should have had time to die and to pollute the gas from which these fossil records then formed. As expected, the chemical composition of the observed stars showed elements typical for enrichment by massive stars. However, the new analysis unexpectedly also revealed elements usually thought to be produced only by stars of smaller masses. Fast-rotating massive stars on the other hand would succeed in manufacturing these elements themselves.

"Alternative scenarios cannot yet be discarded -- but -- we show that if the first generations of massive stars were spinstars, this would offer a very elegant explanation to this puzzle!," says Cristina Chiappini. Team member Urs Frischknecht, a PhD student at the Basel University, is already working on extending the stellar simulations in order to further test the proposed scenario.

The impact of having had an early generation of spinstars in the Universe is manifold. Fast rotation also affects other properties of a star, such as its colour, its lifetime and its luminosity. Spinstars would therefore also have strongly influenced the properties and appearance of the first galaxies which were formed in the Universe. The existence of spinstars is now also supported by recent hydrodynamic simulations of the formation of the first stars of the universe by an independent research group.


Story Source:

The above story is based on materials provided by Leibniz-Institut für Astrophysik Potsdam (AIP). Note: Materials may be edited for content and length.


Journal Reference:

  1. Cristina Chiappini, Urs Frischknecht, Georges Meynet, Raphael Hirschi, Beatriz Barbuy, Marco Pignatari, Thibaut Decressin, André Maeder. Imprints of fast-rotating massive stars in the Galactic Bulge. Nature, 2011; 472 (7344): 454 DOI: 10.1038/nature10000

Cite This Page:

Leibniz-Institut für Astrophysik Potsdam (AIP). "Spinstars: First polluters of the universe? Imprints of fast rotating massive stars in Milky Way's bulge." ScienceDaily. ScienceDaily, 30 April 2011. <www.sciencedaily.com/releases/2011/04/110427132316.htm>.
Leibniz-Institut für Astrophysik Potsdam (AIP). (2011, April 30). Spinstars: First polluters of the universe? Imprints of fast rotating massive stars in Milky Way's bulge. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2011/04/110427132316.htm
Leibniz-Institut für Astrophysik Potsdam (AIP). "Spinstars: First polluters of the universe? Imprints of fast rotating massive stars in Milky Way's bulge." ScienceDaily. www.sciencedaily.com/releases/2011/04/110427132316.htm (accessed September 17, 2014).

Share This



More Space & Time News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) — Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
NASA’s Curiosity Rover Finally Reaches Long-Term Goal

NASA’s Curiosity Rover Finally Reaches Long-Term Goal

Newsy (Sep. 15, 2014) — After more than two years, NASA’s Mars Curiosity Rover reached Mount Sharp, its long-term destination. Video provided by Newsy
Powered by NewsLook.com
SpaceX's Elon Musk Really Wants To Colonize Mars

SpaceX's Elon Musk Really Wants To Colonize Mars

Newsy (Sep. 14, 2014) — Elon Musk has been talking about his goal of colonizing Mars for years now, but how much of it does he actually have figured out, and is it possible? Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:  

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile iPhone Android Web
      Follow Facebook Twitter Google+
      Subscribe RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins