sn1987a

Today is the anniversary of the discovery of the first modern supernova, currently named SN1987A, located in the Tarantala Nebula in the Large Magellanic Cloud.  It was independently discovered by both  Ian Shelton and Oscar Duhalde of the Las Campanas Observatory in Chile on the night of February 23/24, 1987, and within the same 24 hours independently by Albert Jones in New Zealand. Two weeks later, between March 4–12, 1987 it was observed from space by Astron, a large ultraviolet space telescope. The supernova has yet to receive an official name.  

While plenty of modern scientific words can be dated accurately, the older a word is (in general) the harder it is to pin down a date.  The word supernova however, defies this logic.  Late October 1604 (and some sources give the date 6 November 1604) a new and bright object appeared in the sky.  German astronomer and mathematician Johannes Kepler (born 27 December 1571-15 November 1630) noticed the ‘new’ object and unsure what exactly it was, simply named it stella nova, from the Latin words for new star.  It wasn’t until the 1930s that astronomers Walter Baade and Fritz Zwicky started using the term super-nova and by 1938 the hyphen was dropped and the word became supernova.  The first reliably recorded supernova was noted by Pliny in AD 185.  Notable supernovae (note the plural maintains the Latin form and does not take the -s that English mostly uses) occurred in 1054, noted mainly by Chinese and Arabic astronomers, and the supernova of 1572 noted extensively by Tycho Brahe.

Time-lapse animation of SN1987A from 1994 to 2009, video compilation courtesy Mark Macdonald, via Larsson, J. et al. (2011). “X-ray illumination of the ejecta of supernova 1987A”. Nature 474 (7352): 484–486., used with permission under a Creative Commons 3.0 license.  

ALMA spots supernova dust factory

Striking new observations with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope capture, for the first time, the remains of a recent supernova brimming with freshly formed dust. If enough of this dust makes the perilous transition into interstellar space, it could explain how many galaxies acquired their dusty, dusky appearance.

Galaxies can be remarkably dusty places and supernovae are thought to be a primary source of that dust, especially in the early Universe. But direct evidence of a supernova’s dust‐making capabilities has been slim up to now, and could not account for the copious amount of dust detected in young, distant galaxies. But now observations with ALMA are changing that.

“We have found a remarkably large dust mass concentrated in the central part of the ejecta from a relatively young and nearby supernova,” said Remy Indebetouw, an astronomer at the National Radio Astronomy Observatory (NRAO) and the University of Virginia, both in Charlottesville, USA. “This is the first time we’ve been able to really image where the dust has formed, which is important in understanding the evolution of galaxies.”

An international team of astronomers used ALMA to observe the glowing remains of Supernova 1987A, which is in the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way about 160,000 light‐years from Earth. SN 1987A is the closest observed supernova explosion since Johannes Kepler’s observation of a supernova inside the Milky Way in 1604.

Astronomers predicted that as the gas cooled after the explosion, large amounts of dust would form as atoms of oxygen, carbon, and silicon bonded together in the cold central regions of the remnant. However, earlier observations of SN 1987A with infrared telescopes, made during the first 500 days after the explosion, detected only a small amount of hot dust.

With ALMA’s unprecedented resolution and sensitivity, the research team was able to image the far more abundant cold dust, which glows brightly in millimetre and submillimetre light. The astronomers estimate that the remnant now contains about 25 percent the mass of the Sun in newly formed dust. They also found that significant amounts of carbon monoxide and silicon monoxide have formed.

Image credit: ALMA (ESO/NAOJ/NRAO)/A. Angelich. Visible light image: the NASA/ESA Hubble Space Telescope. X-Ray image: The NASA Chandra X-Ray Observatory

Image of the Day: Supernova Ring in Satellite Galaxy of Milky Way

A NASA/ESA Hubble Space Telescope image of a gaseous ring surrounding the supernova 1987A, which exploded on February 23, 1987 in the Large Magellanic Cloud, an irregular satellite galaxy of the Milky Way. The image, taken with the European Space Agency’s Faint Object Camera (FOC), reveals clumpy structure in the ring which indicates that the material is not uniformly distributed.

A star set to explode

Floating at the centre of this new Hubble image is a lidless purple eye, staring back at us through space. This ethereal object, known officially as [SBW2007] 1 but sometimes nicknamed SBW1, is a nebula with a giant star at its centre. The star was originally twenty times more massive than our Sun, and is now encased in a swirling ring of purple gas, the remains of the distant era when it cast off its outer layers via violent pulsations and winds.

But the star is not just any star; scientists say that it is destined to go supernova! 26 years ago, another star with striking similarities went supernova — SN 1987A. Early Hubble images of SN 1987A show eerie similarities to SBW1. Both stars had identical rings of the same size and age, which were travelling at similar speeds; both were located in similar HII regions; and they had the same brightness. In this way SBW1 is a snapshot of SN1987a’s appearance before it exploded, and unsurprisingly, astronomers love studying them together.

At a distance of more than 20 000 light-years it will be safe to watch when the supernova goes off. If we are very lucky it may happen in our own lifetimes…

Image credit: ESA/Hubble & NASA; acknowledgement: Nick Rose

(NASA)  The Mysterious Rings of Supernova 1987A
Image Credit: ESA/Hubble, NASA

What’s causing those odd rings in supernova 1987A? Twenty five years ago, in 1987, the brightest supernova in recent history was seen in the Large Magellanic Cloud. At the center of the above picture is an object central to the remains of the violent stellar explosion. Surrounding the center are curious outer rings appearing as a flattened figure 8. Although large telescopes including the Hubble Space Telescope monitor the curious rings every few years, their origin remains a mystery. Pictured above is a Hubble image of the SN1987A remnant taken last year. Speculation into the cause of the rings includes beamed jets emanating from an otherwise hidden neutron star left over from the supernova, and the interaction of the wind from the progenitor star with gas released before the explosion.

SUPERNOVA!

Today is the anniversary of the discovery of the first modern supernova, currently named SN1987A, located in the Tarantala Nebula in the Large Magellanic Cloud.  It was independently discovered by both  Ian Shelton and Oscar Duhalde of the Las Campanas Observatory in Chile on the night of February 23/24, 1987, and within the same 24 hours independently by Albert Jones in New Zealand. Two weeks later, between March 4–12, 1987 it was observed from space by Astron, a large ultraviolet space telescope. The supernova has yet to receive an official name.  

While plenty of modern scientific words can be dated accurately, the older a word is (in general) the harder it is to pin down a date.  The word supernova however, defies this logic.  Late October 1604 (and some sources give the date 6 November 1604) a new and bright object appeared in the sky.  German astronomer and mathematician Johannes Kepler (born 27 December 1571-15 November 1630) noticed the ‘new’ object and unsure what exactly it was, simply named it stella nova, from the Latin words for new star.  It wasn’t until the 1930s that astronomers Walter Baade and Fritz Zwicky started using the term super-nova and by 1938 the hyphen was dropped and the word became supernova.  The first reliably recorded supernova was noted by Pliny the Elder in AD 185.  Notable supernovae (note the plural maintains the Latin form and does not take the -s that English mostly uses) occurred in 1054, noted mainly by Chinese and Arabic astronomers, and the supernova of 1572 noted extensively by Tycho Brahe.

Time-lapse animation of SN1987A from 1994 to 2009, video compilation courtesy Mark Macdonald, via Larsson, J. et al. (2011). “X-ray illumination of the ejecta of supernova 1987A”. Nature 474 (7352): 484–486., used with permission under a Creative Commons 3.0 license.

Astronomers dissect the aftermath of a supernova

In research published today in the Astrophysical Journal, an Australian led team of astronomers has used radio telescopes in Australia and Chile to see inside the remains of a supernova.

The supernova, known as SN1987A, was first seen by observers in the Southern Hemisphere in 1987 when a giant star suddenly exploded at the edge of a nearby dwarf galaxy called the Large Magellanic Cloud.

In the two and a half decades since then the remnant of Supernova 1987A has continued to be a focus for researchers the world over, providing a wealth of information about one of the Universe’s most extreme events.

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Hubble Sees a Star Set to Explode

Floating at the center of this new Hubble image is a lidless purple eye, staring back at us through space. This ethereal object, known officially as [SBW2007] 1 but sometimes nicknamed SBW1, is a nebula with a giant star at its center. The star was originally twenty times more massive than our sun, and is now encased in a swirling ring of purple gas, the remains of the distant era when it cast off its outer layers via violent pulsations and winds.

But the star is not just any star; scientists say that it is destined to go supernova. Twenty-six years ago, another star with striking similarities went supernova — SN 1987A. Early Hubble images of SN 1987A show eerie similarities to SBW1. Both stars had identical rings of the same size and age, which were travelling at similar speeds; both were located in similar HII regions; and they had the same brightness. In this way SBW1 is a snapshot of SN1987a’s appearance before it exploded, and unsurprisingly, astronomers love studying them together.

At a distance of more than 20 000 light-years it will be safe to watch when the supernova goes off. If we are very lucky it may happen in our own lifetimes.

Credit: ESA/NASA, acknowledgement: Nick Rose.

It’s Got a Ring to It

Here is a beautiful image of a ring nebula around a blue supergiant star. Known as [SBW2007] 1, but usually referred to by the shorter moniker SBW1, the nebula has a star at its center was once 20 times more massive than our Sun. Now it is shrouded in a ring nebula of its own making, having jettisoned some of its outer layers in violent pulsations that mark the beginning of the end for this star.

Located some 25,000 light-years away, SBW1 bears a striking resemblance to SN 1987A, a very well studied supernova that exploded 26 years ago (http://on.fb.me/1hrEfRR). The similarities go beyond looks - the rings around both stars were nearly identical in size, age, and brightness, were moving at similar speeds, and were located in fields of ionized hydrogen (HII regions). In other words, SBW1 is like a snapshot of what SN1987A looked like before it went supernova. Is it any wonder that astronomers think SBW1 is destined to explode? Scientists can use these two objects are ‘before and after‘ examples to better understand stellar evolution and supernovae events.

-JF

Image credit: ESA/Hubble & NASA; Acknowledgements: Nick Rose/Steve Byrne 

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Further reading

Sudden Supernova In M82 Galaxy Rips Apart The Night Sky

Astronomers have been stunned by the appearance of a new supernova in the night sky.

A star in the galaxy M82 has exploded - or at least, the light from the explosion 11.5 million years ago just reached Earth - and scientists are hailing it as a spectacular chance to study a relatively rare event.

The supernova is one of the closest to Earth in more than 20 years, only matched by Supernova SN1993J in 1993, and SN1987A (in 1987, obviously).

Supernovae usually occur when massive stars run out of hydrogen fuel and collapse, before releasing vast amounts of energy in a stellar explosion visible across the galaxy.

But in this case the supernova appears to be a ‘white dwarf supernova’, which occurs when the mass of an isolated white dwarf, with a mass equivalent to that of our Sun but a size similar to the Earth, suddenly grows, collapses and explodes.

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