Astronomers have spotted Mingus, the most distant supernova ever seen.
Mingus was described at the 221st American Astronomical Society meeting in the US.
These lightshows of dying stars have been seen since ancient times, but modern astronomers use details of their light to probe the Universe’s secrets.
Ten billion light-years distant, Mingus will help shed light on so-called dark energy, the force that appears to be speeding up cosmic expansion.
Formally called SN SCP-0401, the supernova was something of a chance find in a survey carried out in part by the Supernova Cosmology Project (SCP) using the Hubble space telescope, first undertaken in 2004.
But the data were simply not good enough to pin down what was seen. As David Rubin of the University of California, Berkeley, lead author on the study, told the AAS meeting, “for a sense of brightness, this supernova is about as bright as a firefly viewed from 3,000 miles away”.
Further news had to wait until astronauts installed the Wide Field Camera 3 on the Hubble telescope in 2009 and again trained it on the candidate, which had – in an SCP tradition of naming supernovae after composers – already been named after jazz musician Charles Mingus.
“Unfortunately, it took the development of Wide Field Camera 3 to bring home what the [2004] measurements meant,” said David Rubin.
“The sensitivity is a few times better, which makes a huge difference, and we have a much cleaner image.”
Astronomers have spotted Mingus, the most distant supernova ever seen
The team went on to confirm that the supernova was in fact a Type 1a – a particular class of exploded star whose light occurs in such a regular way that it is known as a “standard candle”.
What interests astronomers trying to find ever more distant Type 1a supernovae – distant both in space and in time – is the chance to compare them to better-known, more local supernovae.
“We were able to watch these changes in brightness and spectral features for an event that lasted just a few weeks almost 10 billion years ago,” said Saul Perlmutter, who leads the Supernova Cosmology Project.
Prof. Saul Perlmutter shared the 2011 Nobel prize in physics for work with Type 1a supernovae that proved our Universe is speeding up in its expansion.
Elucidating the mysterious force, “dark energy”, which has been invoked as the cause of the expansion, will require careful study of supernovae all the way back to the epoch of the earliest stars.
“We’re seeing two-thirds of the way back to the beginning of the Universe, and we’re getting a little bit of history where the physics of what makes a supernova explode have to all work out the same way there as they do near here,” he told the meeting.
The group’s study is published online and will appear in the Astrophysical Journal on January 20.
The meeting also heard from Joshua Frieman, director of the Dark Energy Survey – a five-year mission using the most powerful camera ever trained on the skies to get to the bottom of the dark matter mystery.
The phone-booth-sized Dark Energy Camera snapped its first images in September 2012 and will begin its formal mission in September this year, looking not only at supernovae but also at three other dark-energy signatures in the cosmos.
Prof. Joshua Frieman said the distant supernova result fits neatly into a story that he hoped the Dark Energy Survey would explore in great detail.
“What they’re doing is using the Hubble telescope to go really deep – we’re going to use the Dark Energy Survey to go very broad,” he explained.
“They’re finding tens of supernovae at these high [distances], and we’re going to find thousands of supernovae not quite as deep. You really need both of those together to really make progress in trying to figure out why the Universe is speeding up.”
Dark Energy Camera, the highest-resolution camera ever built, has begun its quest to pin down the mysterious stuff that makes up nearly three-quarters of our Universe.
The Dark Energy Survey’s 570-million-pixel camera will scan some 300 million galaxies in the coming five years.
The goal is to discover the nature of dark energy, which is theorized to be responsible for the ever-faster expansion of the Universe.
Its first image, taken 12 September, focused on the Fornax galaxy cluster.
In time, along with its massive haul of individual galaxies, it will study 100,000 galaxy clusters – the largest stable structures we know of – and 4,000 supernovae, the bright dying throes of stars.
This enormous survey is a collaboration between US, UK, Brazilian, Spanish and German astronomers.
The phone box-sized Dark Energy Camera or DECam is mounted on the 4 m Victor M Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile’s Atacama desert.
The Dark Energy Survey's 570-million-pixel camera will scan some 300 million galaxies in the coming five years
DECam is particularly sensitive to red and infrared light, to better study cosmic objects as distant as eight billion light-years away.
More distant objects are moving away from us – and each other – faster than nearer objects, which causes a shift of their apparent color toward the red end of the spectrum – a “redshift”.
Careful studies of the shifted light from distant supernovae were what first demonstrated this expansion, leading to the 2011 Nobel Prize in physics.
What is believed to be causing this increase in the speed of expansion is called dark energy, making up more than 70% of the “stuff” of the Universe and the focus of the DECam’s mission.
Other efforts hope to get to the bottom of the mystery, including the Boss survey and a future space telescope dediated to the effort called Euclid.
But for now, Will Percival from the University of Portsmouth, a Dark Energy Survey collaborator, said DECam is an exciting prospect.
“This will be the largest galaxy survey of its kind, and the galaxy shapes and positions will tell us a great deal about the nature of the physical process that we call dark energy, but do not currently understand,” he said.
The survey will tackle the problem in four ways.
It will study the same kind of supernovae that led to the Nobel Prize, in a bid to unravel the “expansion history” of the Universe – when its expansion increased and decreased over billions of years.
It will also map out in 3D the distribution of galaxy clusters, measuring what are known as baryon acoustic oscillations – literally relics of the sound echoes of the Big Bang.
By counting the clusters and plotting out when they evidently formed, the survey can feed back to computer models that map out how we think the Universe organized itself in its earliest years.
And studies of the way galaxies and galaxy clusters bend passing light – in a process called weak gravitational lensing – will help to pin down the equally mysterious “dark matter” that is believed to make up more than 80% of the Universe’s mass.
DECam will now be run through a series of tests and will begin the official survey in December.
With each snapshot it acquires, it will see an apparent area of the sky 20 times larger than the full moon.
In its full five-year run, it should capture an eighth of the full sky.
“The achievement of first light through the Dark Energy Camera begins a significant new era in our exploration of the cosmic frontier,” said James Siegrist, associate director of science for high-energy physics at the US Department of Energy, which oversaw the instrument’s construction.
“The results of this survey will bring us closer to understanding the mystery of dark energy and what it means for the Universe.”
What is redshift?
• The term “redshift” arises from the fact that light from more distant objects shows up on Earth more red than when it left its source
• The color shift comes about because of the Doppler effect, which acts to “stretch” or “compress” waves from moving objects
• It is at work in the sound of a moving siren: an approaching siren sounds higher-pitched and a receding one sounds lower-pitched
• In the case of light, approaching objects appear more blue and receding objects appear more red
• The expansion of the Universe is accelerating, so in general, more distant objects are moving away from us (and each other, and everything else) more quickly than nearer ones
• At cosmic distances, the shift can profoundly affect the color – the factor by which the wavelength is “stretched” is called the redshift
Dark energy and dark matter mysteries
• Gravity acting across vast distances does not seem to explain what astronomers see
• Galaxies, for example, should fly apart; some other mass must be there holding them together
• Astrophysicists have thus postulated “dark matter” – invisible to us but clearly acting on galactic scales
• At the greatest distances, the Universe’s expansion is accelerating
• Thus we have also “dark energy” which acts to drive the expansion, in opposition to gravity
• The current theory holds that 73% of the Universe is dark energy, 23% is dark matter, and just 4% the kind of matter we know well
A coalition of 15 states, members of European Union, has announced plans to build the biggest telescope in the world.
The mirror inside the telescope will measure 39 metres across – four times wider than today’s biggest telescope – and it will be so powerful that astronomers will even be able to observe dark, rocky planets far beyond our solar system.
The European Southern Observatory (ESO) project is supported by 15 members of the European Union and has the catchy name “European Extremely Large Telescope”… even if it will be built in Chile’s Atacama Desert, to avoid light pollution.
The twin infrared/optical telescope will sit on top of a 3,060 metre mountaintop, giving unparralled views of the sky above, and should hopefully come online in 2022.
Astronomers hope the observatory will help provide insights into the formation of galleries and the nature of black holes
They also hope to shed light on two of the biggest mysteries of our universe – the formation of “dark matter”, which cannot be directly observed but is hypothesized to make up most of the mass of the universe, and “dark energy”, which appears to driving the universe to expand at an accelerating rate.
ESO project is supported by 15 members of the European Union and has the catchy name “European Extremely Large Telescope” even if it will be built in Chile's Atacama Desert, to avoid light pollution
ESO agreed to the optical/infrared telescope in Garching, Germany, (E-ELT) Programme, pending confirmation of final referendums.
All of ESO’s member states have already expressed very strong support for the E-ELT project.
At the council meeting, Austria, the Czech Republic, Germany, the Netherlands, Sweden and Switzerland voted in favor of the start of the E-ELT programme.
Four further countries voted in favor ad referendum: Belgium, Finland, Italy, and the UK.
The project has an estimated cost of 1,083 million Euros ($1,320 million).
ESO director general, Tim de Zeeuw said: “This is an excellent outcome and a great day for ESO.
“We can now move forward on schedule with this giant project.”
2012 marks the 50th anniversary of the founding of the ESO. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the UK.
The team operates three observing sites in Chile: La Silla, Paranal and Chajnantor.
At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes.
