Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Star on the Run

10.11.2005


Speeding Star Observed with VLT Hints at Massive Black Hole


Star Ejected from the Large Magellanic Cloud (Artist’s Impression)



Using ESO’s Very Large Telescope, astronomers [1] have recorded a massive star moving at more than 2.6 million kilometres per hour. Stars are not born with such large velocities. Its position in the sky leads to the suggestion that the star was kicked out from the Large Magellanic Cloud, providing indirect evidence for a massive black hole in the Milky Way’s closest neighbour. These results will soon be published in the Astrophysical Journal Letters [2].

“At such a speed, the star would go around the Earth in less than a minute!”, says Uli Heber, one of the scientists at the Dr. Remeis-Sternwarte (University of Erlangen-Nürnberg, Germany) and the Centre for Astrophysics Research (University of Hertfordshire, UK) who conducted the study.


The hot massive star, (named HE 0437-5439), was discovered in the framework of the Hamburg/ESO sky survey far out in the halo of the Milky Way, towards the Doradus Constellation (“the Swordfish”).

“This is a rather unusual place for such a star: massive stars are ordinarily found in the disc of the Milky Way”, explains Ralf Napiwotzki, another member of the team. “Our data obtained with the UVES instrument on the Very Large Telescope, at Paranal (Chile), confirm the star to be rather young and to have a chemical composition similar to our Sun.”

The data also revealed the high speed of the star, solving the riddle of its present location: the star did not form in the Milky Way halo, but happens to be there while on its interstellar – or intergalactic – travel.

“But when we calculated how long it would take for the star to travel from the centre of our Galaxy to its present location, we found this to be more than three times its age”, says Heber. “Either the star is older than it appears or it was born and accelerated elsewhere”, he adds.

As a matter of fact, HE0457-5439 lies closer to one of the Milky Way satellite galaxies, the Large Magellanic Cloud, located 160,000 light-years away from us. The astronomers find it likely for the star to have reached its present position had it been ejected from the centre of the LMC. This could imply the existence of a massive black hole inside the LMC, in order to have imparted the speeding star the necessary kick.

Another explanation would require the star to be the result of the merging of two stars. In this case, the star could be older that presently thought, giving it time to have travelled all the way from the Milky Way Centre. This scenario, however, requires quite some fine-tuning. The astronomers are now planning new observations to confirm one of the two scenarios.

The full text of this ESO Press release 27/05 and the associated artist’s impression is available at http://www.eso.org/outreach/press-rel/pr-2005/pr-27-05.html

Notes

[1] The astronomers are Heinz Edelmann (Dr. Remeis-Sternwarte of the University of Erlangen-Nürnberg, Germany, now at University of Texas, Austin, USA), Ralf Napiwotzki (Centre for Astrophysics Research, University of Hertfordshire, UK), Uli Heber (Dr. Remeis-Sternwarte of the University of Erlangen-Nürnberg, Germany), Norbert Christlieb and Dieter Reimers (Hamburger Sternwarte, Germany).

[2] The paper “HE 0437-5439 – an unbound hyper-velocity main-sequence B-type star” by H. Edelmann et al., will appear in a few weeks in Astrophysical Journal Letters.

Henri Boffin | alfa
Further information:
http://www.eso.org/outreach/press-rel/pr-2005/pr-27-05.html

More articles from Physics and Astronomy:

nachricht Water without windows: Capturing water vapor inside an electron microscope
13.12.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

nachricht Columbia engineers create artificial graphene in a nanofabricated semiconductor structure
13.12.2017 | Columbia University School of Engineering and Applied Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>