How the 'Pillars of Creation' … were created
The 'Pillars of Creation', an image made with the Hubble Space Telescope in 1995, is one of the most famous astronomical views. It shows how 'elephant trunks' of cooler interstellar gas are eroded by the intense radiation and winds from nearby massive stars.
National Astronomy Meeting in Portsmouth.Now Scott Balfour, an astronomer at Cardiff University, has run a new simulation where similar structures appear with a remarkably close appearance to their real life counterparts. He also suggests that the stars that make these structures are of little help in forming new siblings. On Thursday 26 June Scott will present his results in a talk at the
The massive O-type stars, more than 16 times as 'heavy' as our Sun, have short but dramatic lives. During their most stable phase on the so-called main sequence, they have surface temperatures of more than 30,000 degrees Celsius (on the Sun the surface is about 5500 degrees), are strong sources of ultraviolet light and emit copious material in a powerful wind.
All of this shapes their surroundings. The O-type stars heat any interstellar gas in their vicinity, creating bubbles which act like snow ploughs sweeping up surrounding colder material. In these regions, where gas is compressed, large numbers of new stars are seen forming so many scientists argue that the O stars drive star formation.
In his new work, Scott has tried to test this idea by simulating the way the gas behaves over a period of 1.6 million years, a simulation that took several weeks of computing time to calculate. His model explored what would happen when a massive star forms in a smooth cloud of gas that is already collapsing under its own weight.
Light from the O-type star creates a bubble in the cloud as expected, but its future can follow one of three paths. It may expand forever; expand, contract a little and then become almost stationary or expand and then contract all the way back to the centre of the cloud. Scott found that only the second case leads to prolific star formation and even then only under very specific conditions.
He comments: "If I'm right, it means that O-type and other massive stars play a much more complex role than we previously thought in nursing a new generation of stellar siblings to life."
His model also neatly replicates the bright rims and pillars seen in the Hubble image, which seem to form naturally along the outer edge of the bubble as it breaks up.
Scott adds: "The model neatly produces exactly the same kind of structures seen by astronomers in the classic 1995 image, vindicating the idea that giant O-type stars have a major effect in sculpting their surroundings."
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The RAS National Astronomy Meeting (NAM 2014) will bring together more than 600 astronomers, space scientists and solar physicists for a conference running from 23 to 26 June in Portsmouth. NAM 2014, the largest regular professional astronomy event in the UK, will be held in conjunction with the UK Solar Physics (UKSP), Magnetosphere Ionosphere Solar-Terrestrial physics (MIST) and UK Cosmology (UKCosmo) meetings. The conference is principally sponsored by the Royal Astronomical Society (RAS), the Science and Technology Facilities Council (STFC) and the University of Portsmouth. Meeting arrangements and a full and up to date schedule of the scientific programme can be found on the official website and via Twitter.
The University of Portsmouth is a top-ranking university in a student-friendly waterfront city. It's in the top 50 universities in the UK, in The Guardian University Guide League Table 2014 and is ranked in the top 400 universities in the world, in the most recent Times Higher Education World University Rankings 2013. Research at the University of Portsmouth is varied and wide ranging, from pure science – such as the evolution of galaxies and the study of stem cells – to the most technologically applied subjects – such as computer games design. Our researchers collaborate with colleagues worldwide, and with the public, to develop new insights and make a difference to people's lives. Follow the University of Portsmouth on Twitter.
The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3800 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others. Follow the RAS on Twitter.
The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security. The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. It enables UK researchers to access leading international science facilities for example in the area of astronomy, the European Southern Observatory. Follow STFC on Twitter.