Featured Research

from universities, journals, and other organizations

Stars Forming Just Beyond Black Hole's Grasp At Galactic Center

Date:
January 6, 2009
Source:
Harvard-Smithsonian Center for Astrophysics
Summary:
The center of the Milky Way presents astronomers with a paradox: It holds young stars, but no one is sure how those stars got there. The galactic center is wracked with powerful gravitational tides stirred by a 4 million solar-mass black hole. Those tides should rip apart molecular clouds that act as stellar nurseries, preventing stars from forming in place. Yet the alternative -- stars falling inward after forming elsewhere -- should be a rare occurrence.

This artist's concept shows young, blue stars encircling a supermassive black hole at the core of a spiral galaxy like the Milky Way. The background stars are the typical older, redder population of stars that inhabit the cores of most galaxies (including our own). CfA astronomers caught two stars in the act of forming within a few light-years of the Milky Way's center. Their find demonstrates that stars can form at our galaxy's core despite the powerful gravitational tides generated by the black hole.
Credit: NASA, ESA, and A. Schaller (for STScI)

The center of the Milky Way presents astronomers with a paradox: it holds young stars, but no one is sure how those stars got there. The galactic center is wracked with powerful gravitational tides stirred by a 4 million solar-mass black hole. Those tides should rip apart molecular clouds that act as stellar nurseries, preventing stars from forming in place. Yet the alternative – stars falling inward after forming elsewhere – should be a rare occurrence.

Related Articles


Using the Very Large Array of radio telescopes, astronomers from the Harvard-Smithsonian Center for Astrophysics and the Max Planck Institute for Radio Astronomy have identified two protostars located only a few light-years from the galactic center. Their discovery shows that stars can, in fact, form very close to the Milky Way's central black hole.

"We literally caught these stars in the act of forming," said Smithsonian astronomer Elizabeth Humphreys. She presented the finding today at a meeting of the American Astronomical Society in Long Beach, Calif.

The center of the Milky Way is a mysterious region hidden behind intervening dust and gas, making it hard to study. Visible light doesn't make it out, leaving astronomers no choice but to use other wavelengths like infrared and radio, which can penetrate dust more easily.

Humphreys and her colleagues searched for water masers—radio signals that serve as signposts for protostars still embedded in their birth cocoons. They found two protostars located seven and 10 light-years from the galactic center. Combined with one previously identified protostar, the three examples show that star formation is taking place near the Milky Way's core.

Their finding suggests that molecular gas at the center of our galaxy must be denser than previously believed. A higher density would make it easier for a molecular cloud's self-gravity to overcome tides from the black hole, allowing it to not only hold together but also collapse and form new stars.

The discovery of these protostars corroborates recent theoretical work, in which a supercomputer simulation produced star formation within a few light-years of the Milky Way's central black hole.

"We don't understand the environment at the galactic center very well yet," Humphreys said. "By combining observational studies like ours with theoretical work, we hope to get a better handle on what's happening at our galaxy's core. Then, we can extrapolate to more distant galaxies."

Humphreys' co-authors are Mark Reid (Harvard-Smithsonian Center for Astrophysics) and Karl Menten (Max Planck Institute for Radio Astronomy).


Story Source:

The above story is based on materials provided by Harvard-Smithsonian Center for Astrophysics. Note: Materials may be edited for content and length.


Cite This Page:

Harvard-Smithsonian Center for Astrophysics. "Stars Forming Just Beyond Black Hole's Grasp At Galactic Center." ScienceDaily. ScienceDaily, 6 January 2009. <www.sciencedaily.com/releases/2009/01/090105131212.htm>.
Harvard-Smithsonian Center for Astrophysics. (2009, January 6). Stars Forming Just Beyond Black Hole's Grasp At Galactic Center. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2009/01/090105131212.htm
Harvard-Smithsonian Center for Astrophysics. "Stars Forming Just Beyond Black Hole's Grasp At Galactic Center." ScienceDaily. www.sciencedaily.com/releases/2009/01/090105131212.htm (accessed October 25, 2014).

Share This



More Space & Time News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: China Launches Moon Orbiter

Raw: China Launches Moon Orbiter

AP (Oct. 24, 2014) China launched an experimental spacecraft Friday to fly around the moon and back to Earth in preparation for the country's first unmanned return trip to the lunar surface. (Oct. 24) Video provided by AP
Powered by NewsLook.com
China Prepares Unmanned Mission To Lunar Orbit

China Prepares Unmanned Mission To Lunar Orbit

Newsy (Oct. 23, 2014) The mission is China's next step toward automated sample-return missions and eventual manned missions to the moon. Video provided by Newsy
Powered by NewsLook.com
Russian Cosmonauts Kick Off Final Spacewalk of 2014

Russian Cosmonauts Kick Off Final Spacewalk of 2014

Reuters - US Online Video (Oct. 22, 2014) Russian cosmonauts Maxim Suraev and Alexander Samokutyaev step outside the International Space Station to perform work on the exterior of the station's Russian module. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. 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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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