Astrophysicists 'weigh' galaxy's most massive star

September 19, 2008

Theoretical models of stellar formation propose the existence of very massive stars that can attain up to 150 times the mass of our Sun.

Until very recently, however, no scientist had discovered a star of more than 83 solar masses. Now an international team of astrophysicists, led by Université de Montréal researchers from the Centre de recherche en astrophysique du Québec (CRAQ), has found and "weighed" the most massive star to date.

Olivier Schnurr, Jules Casoli and André-Nicolas Chené, all graduates of the Université de Montréal, and professors Anthony F. J. Moffat and Nicole St-Louis, successfully "weighed" a star of a binary system with a mass 116 times greater than that of the Sun, waltzing with a companion of 89 solar masses, doubly beating the previous record and breaking the symbolic barrier of 100 solar masses for the first time.

Located in the massive star cluster NGC 3603, the supermassive star system, known under the name of A1, has a rotation period of 3.77 days. The masses were calculated by a combination of observations made with the SINFONI instrument, an integral field spectrograph operating on the Very Large Telescope on the site of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) in Chile, and infrared images coming from the Hubble Space Telescope.

The stars forming the A1 system are so massive and bright that the light they transmit shows characteristics that only "Wolf-Rayet" stars possess. Within the context of this work, a binary system transmitting X-rays at a power almost never seen in our Galaxy was also discovered near NGC 3603-A1.

Notes: NGC 3603 (entry number 3603 of the New General Catalogue) is a giant HII region in the Constellation Carina, in the Carina arm of our spiral Galaxy, the Milky Way, about 20,000 light years from the Sun. It was discovered by John Frederick William Herschel in 1834. NGC 3603 has an open cluster at its centre that contains approximately 2,000 bright and massive stars.

A Wolf-Rayet star is a hot, massive and evolved star exhibiting a very high loss of mass due to a strong stellar wind (similar to the solar wind).

Article: www3.interscience.wiley.com/journal/121358317/abstract?CRETRY=1&SRETRY=0

Source: University of Montreal

Explore further: A spectacular landscape of star formation

Related Stories

A spectacular landscape of star formation

August 20, 2014

This image, captured by the Wide Field Imager at ESO's La Silla Observatory in Chile, shows two dramatic star formation regions in the Milky Way. The first, on the left, is dominated by the star cluster NGC 3603, located ...

Candidate most massive binary star identified

April 17, 2013

Astronomers have observed a binary star that potentially weighed 300 to 400 solar masses at birth. The present day total mass of the two stars is between 200 and 300 times that of the Sun, depending on its evolutionary stage, ...

Stars: How big is big?

December 12, 2011

You may have seen one of these astronomical scale picture sequences, where you go from the Earth to Jupiter to the Sun, then the Sun to Sirius – and all the way up to the biggest star we know of VY Canis Majoris. However, ...

Image: Starburst Cluster Shows Celestial Fireworks

July 6, 2010

(PhysOrg.com) -- Like a July 4 fireworks display, a young, glittering collection of stars looks like an aerial burst. The cluster is surrounded by clouds of interstellar gas and dust—the raw material for new star formation. ...

Recommended for you

Binary star system precisely timed with pulsar's gamma-rays

July 31, 2015

Pulsars are rapidly rotating compact remnants born in the explosions of massive stars. They can be observed through their lighthouse-like beams of radio waves and gamma-rays. Scientists at the Max Planck Institute for Gravitational ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

gopher65
not rated yet Sep 19, 2008
Does anyone else out there twitch everytime they remember that NGC stands for "New Galactic Catalogue"? "New" indeed.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.