* Astronomy

Members Login
Post Info TOPIC: (SN) 1987A


L

Posts: 130042
Date:
RE: (SN) 1987A
Permalink  
 




This artist's impression of the material around a recently exploded star, known as Supernova 1987A (or SN 1987A), is based on observations which have for the first time revealed a three dimensional view of the distribution of the expelled material. The observations were made by astronomers using ESO's Very Large Telescope. The original blast was not only powerful, according to the new results. It was also more concentrated in one particular direction. This is a strong indication that the supernova must have been very turbulent, supporting the most recent computer models. This video shows the different elements present in SN 1987A: two outer rings, one inner ring and the deformed, innermost expelled material.

__________________


L

Posts: 130042
Date:
Permalink  
 

Exploding star reconstructed in 3D

Astronomers have put together the first three-dimensional reconstruction of an exploding star (known as a supernova).
Read more

__________________


L

Posts: 130042
Date:
Supernova 1987A
Permalink  
 


Seeing a Stellar Explosion in 3D

Astronomers using ESO's Very Large Telescope have for the first time obtained a three-dimensional view of the distribution of the innermost material expelled by a recently exploded star. The original blast was not only powerful, according to the new results. It was also more concentrated in one particular direction. This is a strong indication that the supernova must have been very turbulent, supporting the most recent computer models.
Unlike the Sun, which will die rather quietly, massive stars arriving at the end of their brief life explode as supernovae, hurling out a vast quantity of material. In this class, Supernova 1987A (SN 1987A) in the rather nearby Large Magellanic Cloud occupies a very special place. Seen in 1987, it was the first naked-eye supernova to be observed for 383 years, and because of its relative closeness, it has made it possible for astronomers to study the explosion of a massive star and its aftermath in more detail than ever before. It is thus no surprise that few events in modern astronomy have been met with such an enthusiastic response by scientists.

Read more

__________________


L

Posts: 130042
Date:
Permalink  
 

Title: Could the compact remnant of SN 1987A be a quark star?
Authors: T.C. Chan, K.S. Cheng, T. Harko, H.K. Lau, L.M. Lin, W.M. Suen, X.L. Tian

The standard model for Type II supernovae explosion, confirmed by the detection of the neutrinos emitted during the supernova explosion, predicts the formation of a compact object, usually assumed to be a neutron star. However, the lack of the detection of a neutron star or pulsar formed in the SN 1987A still remains an unsolved mystery. In this paper we suggest that the newly formed neutron star at the center of SN1987A may undergo a phase transition after the neutrino trapping time scale (~10 s). Consequently the compact remnant of SN 1987A may be a strange quark star, which has a softer equation of state than that of neutron star matter. Such a phase transition can induce the stellar collapse and result in a large amplitude stellar oscillations. We use a three dimensional Newtonian hydrodynamic code to study the time evolution of the temperature and density at the neutrinosphere. Extremely intense pulsating neutrino fluxes, with submillisecond period and with neutrino energy (> 30 MeV) can be emitted because the oscillations of the temperature and density are out of phase almost 180 degree. If this is true we predict that the current X-ray emission from the compact remnant of SN 1987A will be lower than 10^34 erg s-1, and it should be a thermal bremsstrahlung spectrum for a bare strange star with surface temperature of around ~10^7 K.

Read more  (100kb, PDF)

__________________


L

Posts: 130042
Date:
RE: (SN) 1987A
Permalink  
 


SANDULEAK -69°220 = RADCLIFFE 127 = HDE 269858

Source (IAUC 8913)

__________________


L

Posts: 130042
Date:
Supernova 1987A
Permalink  
 


Two decades after it lit up Earths southern skies, the exploding star known as Supernova 1987A is still putting on the fireworks. The first supernova of 1987 had astronomers in a tizzy because it was the brightest one seen since 1604before the invention of the telescope. Instantly they started a global monitoring program, watching for every clue about how massive stars die. Now the Hubble Space Telescope has delivered the pièce de résistance, capturing the supernovas blast wave as it sweeps into interstellar space, heating a surrounding ring of gas into a glowing cosmic rosary.

sn1987_600
Expand (63kb, 600 x 294)
Courtesy of NASA/ESA/P.Challis/R.Kirshner
(Harvard Smithsonian Center for Astrophysics)


Read more

__________________


L

Posts: 130042
Date:
RE: (SN) 1987A
Permalink  
 


Twenty years after the first detection of SN 1987A, the nearest supernova ever detected since the invention of the telescope, XMM-Newton provided a fresh-new view of this object. The source keeps brightening - XMM-Newton confirms.

SN 1987A
Expand (113kb, 1024 x 768)
Credits: ESA/EPIC/MPE

The supernova SN 1987A in the Large Magellanic Cloud is the nearest supernova detected since the invention of the telescope. Almost 20 years after its discovery on 23 February 1987, XMM-Newton observed the stellar remnant in X-rays on 17 January 2007. Continuously brightening since the first detection in X-rays by ROSAT in 1992, it now outshines all other X-ray sources in its immediate neighbourhood and it is more than ten times brighter as compared to the first-light observations of XMM-Newton in January 2000.

Read more

__________________


L

Posts: 130042
Date:
Permalink  
 

February 24, 2007 marks the 20th anniversary of one of the most spectacular events observed by astronomers in modern times, Supernova 1987A. The destruction of a massive star in the Large Magellanic Cloud, a nearby galaxy, spawned detailed observations by many different telescopes, including NASA's Chandra X-ray Observatory and Hubble Space Telescope. The outburst was visible to the naked eye, and is the brightest known supernova in almost 400 years.

sn87a
Expand (175kb, 1024 x 244)
Credit: X-ray: NASA/CXC/PSU/S.Park & D.Burrows.; Optical: NASA/STScI/CfA/P.Challis

Position(J2000): RA 05h 35m 28.30s | Dec -69º 16' 11.10"

This composite image shows the effects of a powerful shock wave moving away from the explosion. Bright spots of X-ray and optical emission arise where the shock collides with structures in the surrounding gas. These structures were carved out by the wind from the destroyed star. Hot-spots in the Hubble image (pink-white) now encircle Supernova 1987A like a necklace of incandescent diamonds. The Chandra data (blue-purple) reveals multimillion-degree gas at the location of the optical hot-spots. These data give valuable insight into the behavior of the doomed star in the years before it exploded.

Source

__________________


L

Posts: 130042
Date:
Permalink  
 

A merger of two stars and the deadly dance that preceded it produced the distinctive triple ring system of supernova 1987A, a new study says.
SN 1987A exploded within the Milky Way galaxy on 23 February 1987 and is the nearest supernova observed since the one observed by Johannes Kepler in 1604. The unusual chemistry of SN 1987A has led many astronomers to suspect the progenitor star had merged with another star shortly before the explosion.
Like many stars that have reached the end of their lives, the star that produced SN 1987A is surrounded by a gaseous nebula, sometimes called planetary nebulae for historical reasons. These form when massive stars begin to die, bloating into red giants before shedding as much as half their mass as gas and dust nebulae, which often take on a pinched appearance.
Scientists have had difficulty explaining the bizarre and intricate shapes of these nebulae. Some have suggested the merger process might explain the triple rings of SN 1987A, but it has been unclear whether this was correct.
Now, a pair of astronomers has reproduced the triple rings in a simulation of the two stars spiralling in and merging, providing new evidence that this process produced the puzzling shape. The simulation was produced by Thomas Morris and Philipp Podsiadlowski, both of the University of Oxford, UK.

Read more

__________________


L

Posts: 130042
Date:
Supernova 1987A
Permalink  
 


Twenty years ago next month, the closest and brightest supernova in four centuries lit up the southern sky, wowing astronomers and the public alike.
Ongoing observations of the exploded star, called supernova 1987A, provided important tests for theories of how stars die, but it also raised some new questions. Principal among these was how a bizarre, triple-ring nebula surrounding the supernova - ejected by the star a few thousand years before it exploded - originated. Astronomers devised a complicated theory that, within a relatively short period of time, the original star, a red supergiant, merged with a companion and started spinning rapidly, then underwent a transition to a blue supergiant, and finally exploded.
University of California, Berkeley, astronomer Nathan Smith has proposed a different theory for the origin of the nebula, arguing instead that SN1987A's progenitor star may have been in a class of unstable blue supergiant stars, called luminous blue variables, which eject material from their surfaces in recurring, volcano-like eruptions before they finally die in a supernova explosion.

Read more

__________________
«First  <  1 2 3 4  >  Last»  | Page of 4  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard