30 Doradus in the Large Magellanic Cloud

star-forming-region-R136

Image: HST, NASA, ESA, and E. Sabbi (ESA/STScI) Acknowledgment: R. O’Connell (University of Virginia) and the Wide Field Camera 3 Science Oversight Committee

Hubble’s circumstantial evidence for the impending collision comes from seeing an elongated structure in the cluster at upper left, and from measuring a different age between the two clusters. Also, the unusually large number of high-velocity stars around 30 Doradus can finally be explained if a small cluster has merged into the big cluster R136 in the centre of the Tarantula Nebula.

This nearby example of cluster interaction yields insights into how star clusters may have formed in the early Universe. The Hubble observations, made with the Wide Field Camera 3, were taken 20-27 October, 2009. The blue colour is light from the hottest, most massive stars; the green from the glow of oxygen; and the red from fluorescing hydrogen.

The R136 cluster in the Tarantula nebula (below) contains the most massive stars known. The lead author of this 2010 study, Paul A. Crowther of the University of Sheffield, has a number of online resources providing an overview of the region and the evidence for these extremely high stellar masses. This article [pdf] contains an image, made using adaptive optics at the VLT, in which the star originally known as R136a is resolved into five components, the most massive of which is estimated to have 320 solar masses. If this sounds remarkable, consider that as recently as 1981, R136a was thought to be a 2500 solar mass behemoth! In a new paper today, another object in the region, R144, is shown to be a spectroscopic binary with a total mass content in the 200 – 300 solar mass range. The paper is H. Sana et al., “R144 revealed as a double-lined spectroscopic binary”, arXiv preprint [pdf].

r136

Update: the appearance of so-called “super-canonical” stars – stars more massive than the star formation process should make by itself – is explained naturally by mergers according to recent and innovative N-body simulations.

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2 Responses to “30 Doradus in the Large Magellanic Cloud”

  1. […] about eta Carinae and the likelihood it may go supernova very soon. Suffice to say it is one of the most massive stars in the […]

  2. […] a hundred Suns. Wikipedia has a list of the most massive stars. Top of the list are the stars in R136 in the Large Magellanic Cloud, and at the bottom is the extreme red supergiant VY Canis Majoris […]

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