Hubble Reveals Monster Stars
An international team of scientists using the NASA/ESA Hubble Space Telescope, have identified nine massive stars located within the star cluster of R136 — about 170,000 light years away in the Tarantula Nebula — that have masses over 100 times that of the sun.
This is the largest sample of very massive stars identified to date. However, the current record holder, R136a1, still keeps the title as the most massive star known in the Universe, at over 250 solar masses.
“Together these nine stars outshine the Sun by a factor of 30 million,”according to a statement from the European Space Agency, which operates the telescope with NASA.
In addition to those nine headliners, the young star cluster R136 also contains dozens of stars of at least 50 solar masses.
The discovery was made using Hubble’s Wide Field Camera 3 (WFC3) using the ultraviolent spatial resolution of the Space Telescope Imaging Spectrograph (STIS) and represents the largest sample of massive stars discovered to date and raise new questions regarding the formation of these star types.
“Because they are so massive, they are all close to their so-called Eddington limit, which is the maximum luminosity a star can have before it rips itself apart; and so they’ve got really powerful outflows. They are shedding mass at a fair rate of knots,” the University of Sheffield’s Paul Crowther told the BBC.
The discovery raises many new questions about the formation of massive stars — in fact, when the first four stars in R136 were discovered in 2010, researchers were shocked to find that stars could even get so massive.
“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,” Crowther said in the statement.