Spitzer Spies Ghostly Magnetar

Article written: 28 May , 2008
Updated: 24 Dec , 2015
by

Spitzer Space Telescope Image of Magnetar SGR 1900+14

If only it were closer to Halloween. NASA’s Spitzer Space Telescope has captured an infrared image showing a ghostly ring extending seven light-years across around the corpse of a massive star, called a magnetar . The collapsed star, called Magnetar SGR 1900+14, is unlike anything ever seen before. Scientists believe this object may have formed in 1998 when the magnetar erupted in a giant flare. They believe the crusty surface of the magnetar cracked, sending out a flare, or blast of energy, that excavated a nearby cloud of dust, leaving an outer, dusty ring. “The universe is a big place and weird things can happen,” said Stefanie Wachter of NASA’s Spitzer Science Center.

Wachter is lead author of a paper about the findings in this week’s Nature. The ring is oblong, with dimensions of about seven by three light-years. It appears to be flat, or two-dimensional, but the scientists said they can’t rule out the possibility of a three-dimensional shell.

Magnetars are formed when a giant star ends its life in a supernova explosion, leaving behind a super dense neutron star with an incredibly strong magnetic field. These are the cores of massive stars that blew up in supernova explosions, but unlike other dead stars, they slowly pulsate with X-rays and have tremendously strong magnetic fields. The ring seen by Spitzer could not have formed during the original explosion, as any material as close to the star as the ring would have been disrupted by the supernova shock wave.

This composite image was taken using all three of Spitzer’s science instruments. The blue color represents 3.6-micron infrared light taken by the infrared array camera, green is 16-micron light from the infrared spectograph, and red is 24-micron radiation from the multiband imaging photometer.

Original News Source: NASA


7 Responses

  1. greg your last name says

    nancy, you have been on a roll with new info!! amazing stuff.

  2. Why, thank you! I have a pretty fun job, especially this week.

  3. dmedici says

    Three questions for the board:

    At one point, this magnetar must have gone nova to shed it’s gas into this formation, correct?

    How do we know if we’re currently looking at a nova or supernova if it’s nothing more than an incredibly bright flash of light?

    How do we know if this has already gone nova or supernova? Wouldn’t both produce the same gas visuals/signatures?

    Thanks in advance for your answers!

  4. Andy says

    Can someone explain to me how a neutron star can maintain such a powerful magnetic field? I thought that magnetic fields were generated by the movement of charged particles.

  5. Astrofiend says

    # Andy Says:
    May 29th, 2008 at 3:34 am

    “Can someone explain to me how a neutron star can maintain such a powerful magnetic field? I thought that magnetic fields were generated by the movement of charged particles.”
    I can’t explain it too well, but here’s a basic rundown…

    Although Neutron stars are ‘sold’ as being giant balls of neutrons, in all probability it is nowhere near that simple. According to generally accepted theory, they are composed of a number of different types of particles and layers, and due to increasing pressure as one moves from the surface to the core (and a number of other effects), a number of different physical states arise.

    One of these states is a region of superconducting protons, whose existence is implied by the fundamental theory of how neutrons behave quantum mechanically at such immense pressures. Other charged particles such as electrons are also expected to exist in numbers significant enough to contribute to the overall magnetic field too.

    When the star explodes as a supernova, some physical mechanism ensures that these charged particles retain a ‘memory’ of the progenitor star’s old magnetic field – the laws of electromagnetism clearly state that such a field must be conserved if it cannot be dissipated in any other way during the explosion. Hence the neutron star continues to generate a similar TOTAL field strength as the original star, but as one nears the neutron star’s surface the field becomes more and more compressed as it is being generated from such a tiny region.

    This is about as far as I can go with this. As a disclaimer – I’m sure there are people here more knowledgeable than I on this topic. Correction of any errors in the above would be graciously accepted…

  6. AJames says

    Drats!! and Double Drats (with whistles)!!

    I was certain this was going to be the big announcement as alluded too in the speculation of the NASA announcement on May 9th, 2008 in this site. It turned out to be a very unspectacular discovery by Chandra observatory.
    I think this “magnetar” discovery was far more important – if only because it shows the true energy and amazing effects of neutron stars. The sheer violence and consequences are truly astonishing – and would make the plot of any decent sci-fi movie plot – and astound all!
    As to question by Andy and the answer by astrofiend – they are certainly on the money. Very simply, and as a general comment, the real reason for the magnetic field generation is the angular momentum and spin of the neutron star itself, whose 5 km body is spinning so fast that it appears like a flat disk instead of a round or elliptical star. This 1000 km per second rotation causes the strong electron flow, which generates in turn the very powerful magnetic field. In pulsars, this directs the energies via the poles, to squirt-out the two ejects that project into space. “Magetars”, as said, are thought to be caused by outbursts from the neutron star sometimes very gross instabilities.

    Note: “Magnastar” is certainly a better name than “magnetar”, but I believe this has not been used to save confusion with several corporations here on Earth., and further, it can be confused with devices considered for some theoretical fusion devices. Sorry, “Magnetar” just does not seem too astronomical object to me!

  7. Andy says

    Thanks Astrofiend! Your explanation helped me to appreciate even more just how unique (and strange)
    magnetars really are.

Leave a Reply