Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble unveils monster stars

18.03.2016

Astronomers using the unique ultraviolet capabilities of the NASA/ESA Hubble Space Telescope have identified nine monster stars with masses over 100 times the mass of the Sun in the star cluster R136. This makes it the largest sample of very massive stars identified to date. The results, which will be published in the Monthly Notices of the Royal Astronomical Society, raise many new questions about the formation of massive stars.

An international team of scientists using the NASA/ESA Hubble Space Telescope has combined images taken with the Wide Field Camera 3 (WFC3) with the unprecedented ultraviolet spatial resolution of the Space Telescope Imaging Spectrograph (STIS) to successfully dissect the young star cluster R136 in the ultraviolet for the first time [1].


The image shows the central region of the Tarantula Nebula in the Large Magellanic Cloud. The young and dense star cluster R136 can be seen at the lower right of the image. This cluster contains hundreds of young blue stars, among them the most massive star detected in the Universe so far.

Using the NASA/ESA Hubble Space Telescope astronomers were able to study the central and most dense region of this cluster in detail. Here they found nine stars with more than 100 solar masses.

Credit: NASA, ESA, P Crowther (University of Sheffield)

R136 is only a few light-years across and is located in the Tarantula Nebula within the Large Magellanic Cloud, about 170 000 light-years away. The young cluster hosts many extremely massive, hot and luminous stars whose energy is mostly radiated in the ultraviolet [2]. This is why the scientists probed the ultraviolet emission of the cluster.

As well as finding dozens of stars exceeding 50 solar masses, this new study was able to reveal a total number of nine very massive stars in the cluster, all more than 100 times more massive as the Sun. However, the current record holder R136a1 does keep its place as the most massive star known in the Universe, at over 250 solar masses. The detected stars are not only extremely massive, but also extremely bright. Together these nine stars outshine the Sun by a factor of 30 million.

The scientists were also able to investigate outflows from these behemoths, which are most readily studied in the ultraviolet. They eject up to an Earth mass of material per month at a speed approaching one percent of the speed of light, resulting in extreme weight loss throughout their brief lives.

“The ability to distinguish ultraviolet light from such an exceptionally crowded region into its component parts, resolving the signatures of individual stars, was only made possible with the instruments aboard Hubble,” explains Paul Crowther from the University of Sheffield, UK, and lead author of the study. “Together with my colleagues, I would like to acknowledge the invaluable work done by astronauts during Hubble’s last servicing mission: they restored STIS and put their own lives at risk for the sake of future science!” [3]

In 2010 Crowther and his collaborators showed the existence of four stars within R136, each with over 150 times the mass of the Sun. At that time the extreme properties of these stars came as a surprise as they exceeded the upper-mass limit for stars that was generally accepted at that time. Now, this new census has shown that there are five more stars with more than 100 solar masses in R136. The results gathered from R136 and from other clusters also raise many new questions about the formation of massive stars as the origin of these behemoths remains unclear [4].

Saida Caballero-Nieves, a co-author of the study, explains: “There have been suggestions that these monsters result from the merger of less extreme stars in close binary systems. From what we know about the frequency of massive mergers, this scenario can’t account for all the really massive stars that we see in R136, so it would appear that such stars can originate from the star formation process.”

In order to find answers about the origin of these stars the team will continue to analyse the gathered datasets. An analysis of new optical STIS observations will also allow them to search for close binary systems in R136, which could produce massive black hole binaries which would ultimately merge, producing gravitational waves.

“Once again, our work demonstrates that, despite being in orbit for over 25 years, there are some areas of science for which Hubble is still uniquely capable,” concludes Crowther.

Notes

[1] R136 was originally listed in a catalogue of the brightest stars in the Magellanic Clouds compiled at the Radcliffe Observatory in South Africa. It was separated into three components a, b, c at the European Southern Observatory, with R136a subsequently resolved into a group of eight stars (a1-a8) at ESO, and confirmed as a dense star cluster with the NASA/ESA Hubble Space Telescope after the first servicing mission in 1993.


[2] Very massive stars are exclusive to the youngest star clusters because their lifetimes are only 2-3 million years. Only a handful of such stars are known in the entire Milky Way galaxy.


[3] STIS’s capabilities were restored in 2009 by astronauts who successfully completed Serving Mission 4 (SM4), one of the Hubble’s most challenging and intense servicing missions, involving five spacewalks.


[4] The ultraviolet signatures of even more very massive stars have also been revealed in other clusters — examples include star clusters in the dwarf galaxies NGC 3125 and NGC 5253. However, these clusters are too distant for individual stars to be distinguished even with Hubble.

More information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The results were published in the paper “The R136 star cluster dissected with Hubble Space Telescope/STIS. I. Far-ultraviolet spectroscopic census and the origin of Heii λ1640 in young star clusters” in the Monthly Notices of the Royal Astronomical Society.

The international team of astronomers in this study consists of Paul A. Crowther (Department of Physics and Astronomy, University of Sheffield, Sheffield, UK), S.M. Caballero-Nieves(Department of Physics and Astronomy, University of Sheffield, Sheffield, UK), K.A. Bostroem (Space Telescope Science Institute, Baltimore MD, USA; Department of Physics, University of California, Davis CA, USA), J. Maíz Apellániz (Centro de Astrobiología, CSIC/INTA, Madrid, Spain), F.R.N. Schneider (Department of Physics, University of Oxford, Oxford, UK; Argelanger-Institut fur Astronomie der Universität Bonn, Bonn, Germany), N.R. Walborn(Space Telescope Science Institute, Baltimore MD, USA), C.R. Angus (Department of Physics and Astronomy, University of Sheffield, Sheffield, UK; Department of Physics, University of Warwick, Coventry, UK), I. Brott (Institute for Astrophysics, Vienna, Austria), A. Bonanos (Institute of Astronomy & Astrophysics, National Observatory of Athens, P. Penteli, Greece), A. de Koter (Astronomical Institute Anton Pannekoek, University of Amsterdam, Amsterdam, Netherlands; Institute of Astronomy, Leuven, Belgium), S.E. de Mink (Astronomical Institute Anton Pannekoek, University of Amsterdam, Amsterdam, Netherlands), C.J. Evans (UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK), G. Gräfener (Armagh Observatory, Armagh, UK), A. Herrero (Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna, La Laguna, Tenerife, Spain), I.D. Howarth (Department of Physics & Astronomy, University College London, London, UK), N. Langer (Argelanger-Institut fur Astronomie der Universität Bonn, Bonn, Germany), D.J. Lennon (European Space Astronomy Centre, ESA, Villanueva de la Cañada, Madrid, Spain), J. Puls (Universitäts-Sternwarte, Munchen, Germany), H. Sana (Space Telescope Science Institute, Baltimore MD, USA; Institute of Astronomy, Leuven, Belgium), J.S. Vink (Armagh Observatory, Armagh, UK).

Links
Images of Hubble
Link to science paper
Image of R136 taken in 2009
ESO release on the discovery of R136a1 in 2010

Contacts

Paul Crowther
University of Sheffield
United Kingdom
Tel: +44-(0)114 222 4291
Email: paul.crowther@sheffield.ac.uk

Saida Caballero-Nieves
University of Sheffield
United Kingdom
Tel: +1 813 400 3765
Email: s.caballero@shef.ac.uk

Mathias Jäger
ESA/Hubble, Public Information Officer
Garching, Germany
Tel: +49 176 62397500
Email: mjaeger@partner.eso.org

Mathias Jäger | ESA/Hubble Media Newsletter
Further information:
http://www.spacetelescope.org/news/heic1605/?lang

More articles from Physics and Astronomy:

nachricht Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas

nachricht Calculating quietness
22.09.2017 | Forschungszentrum MATHEON ECMath

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>