Posted on by Nancy Atkinson

‘Ring’ in the Holidays with New Hubble Bubble Image

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From a Hubble/ESA press release:

A festive, delicate ring –photographed by the Hubble Space Telescope — appears to float serenely in the depths of space, but this apparent calm hides an inner turmoil. The gaseous envelope formed as the expanding blast wave and ejected material from a supernova tore through the nearby interstellar medium. Called SNR B0509-67.5 (or SNR 0509 for short), the bubble is the visible remnant of a powerful stellar explosion in the Large Magellanic Cloud (LMC), a small galaxy about 160,000 light-years from Earth.

Ripples seen in the shell’s surface may be caused either by subtle variations in the density of the ambient interstellar gas, or possibly be driven from the interior by fragments from the initial explosion. The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 18 million km/h.

Astronomers have concluded that the explosion was an example of an especially energetic and bright variety of supernova. Known as Type Ia, such supernova events are thought to result when a white dwarf star in a binary system robs its partner of material, taking on more mass than it is able to handle, so that it eventually explodes.

Hubble’s Advanced Camera for Surveys observed the supernova remnant on 28 October 2006 with a filter that isolates light from the glowing hydrogen seen in the expanding shell. These observations were then combined with visible-light images of the surrounding star field that were imaged with Hubble’s Wide Field Camera 3 on 4 November 2010.

With an age of about 400 years, the supernova might have been visible to southern hemisphere observers around the year 1600, although there are no known records of a “new star” in the direction of the LMC near that time. A much more recent supernova in the LMC, SN 1987A, did catch the eye of Earth viewers and continues to be studied with ground- and space-based telescopes, including Hubble.

8 Replies to “‘Ring’ in the Holidays with New Hubble Bubble Image”

  2. is the expansion slowing down substantially because of contact with interstellar medium? a simple calculation from 18 gm/h expansion and 23 ly diameter gives the age of “bubble” 690 years…

  3. I was disappointed that you missed the connection with planetary nebulae. Seeing such a bubble conjures such perceptions, but the size of the bubble is the key. A SNR being 23 light-years across (0.7 parsecs) is much larger than any known planetary nebulae, which rarely exceeds 3 light years (c.0.2-0.3 parsecs) If this is true, SNR B0509-67.5 is a little more than twice the size of the 960-odd year old Crab Nebula, which is roughly 12 light years (4.5 parsecs) across.

    Also from the velocity of 18 million km/h (11 million miles per hour), is exactly 5000 km.s-1 (as lacalaca said). To travel 23 light-years at this velocity [some 217 trillion kilometres] (excluding slowing down in the interstellar medium), the age calculates as about 1379 years, or 631 AD when it it brightened as a SNR in the southern skies. (as renoor also says)
    (I don’t know where you get the 400 years from. Either the size or the velocity is wrong!)

    There are also some significant problems with the SNR theory here. Supernova are destructive catastrophic explosions, and yet the surface of the bubble looks as smooth as a baby’s bottom. Yet most other SN remnants, the destruction is highly apparent. I.e. The Crab Nebula / M1 / NGC 1952. Even computer simulations shows it is a turbulent affair. Also assuming the expansion of the average SNR is about 1500 km.s-1, then the object’s age would be much older.

    Also I’m surprised you’ve only used the H-alpha image. Surely the full colour image ( heic1018) is much more illuminating (so to speak.)

    Note: I’ve written to Oli Usher of the Hubble/ ESA regarding these particular wayward discrepancies, to see where such assumptions derive. I’ll see what we get back!

    1. Please do, because now you’ve raised my “need to know” flag. [Damn curiosity, taking too much time!]

    2. X-ray observations of SNR B0509 by Chandra back in 2004 identified this object as a remnant of a Type Ia SNR. Observations of a visible light echo from the supernova itself were later used, along with X-ray observations to produce an accurate estimate of the energy released by the supernova that produced this remnant. The observed light echoes also helped researchers to make an age estimate of ~400 years: http://chandra.harvard.edu/photo/2008/snr0509/

      Newer X-ray observations of the SNR by Chandra and XMM-Newton examined more closely the chemical stratification and internal kinematics present and also derived an age consistent with the earlier estimates: http://fr.arxiv.org/PS_cache/arxiv/pdf/1001/1001.0983v3.pdf

      “…I’m surprised you’ve only used the H-alpha image”

      Actually, this is a 4-color composite image of the SNR. The Hubble Heritage entry for SNR B0509 includes the individual images used to produce the color image seen here: http://heritage.stsci.edu/2010/27/original.html

      The HubbleSite also has an annotated version of the color image including scale and orientation data: http://imgsrc.hubblesite.org/hu/db/images/hs-2010-27-b-print.jpg

      (The image you have linked to is a composite X-ray – visible light image, though I’m not sure what X-ray spectral bands were used to construct the X-ray image.)

    3. Comment in moderation, so I’ll try this –

      X-ray observations of SNR B0509 by Chandra back in 2004 identified this object as a remnant of a Type Ia SNR. Observations of a visible light echo from the supernova itself were later used, along with X-ray observations to produce an accurate estimate of the energy released by the supernova that produced this remnant. The observed light echoes also helped researchers to make an age estimate of ~400 years. A page on SNR B0509 on the Chandra site (release date March 20, 2008) has details and a movie of the light echo.

      Newer X-ray observations of the SNR by Chandra and XMM-Newton examined more closely the chemical stratification and internal kinematics present and also derived an age consistent with the earlier estimates. The arXiv identifier for the paper: 1001.0983v3

      “…I’m surprised you’ve only used the H-alpha image”

      Actually, this is a 4-color composite image of the SNR. The Hubble Heritage entry for SNR B0509 includes the four individual black & white images used to produce the color image seen above (only strong emission in the H-alpha+[NII] image). The HubbleSite also has an annotated version of the color image including color-band assignments, scale and orientation data. The image you have linked is actually a X-ray+visible light composite of the SNR. The X-ray image betrays the turbulent nature of the event, in stark contrast to the well-ordered, smooth appearance seen in visible light. The new X-ray image can also be seen at the Chandra site.

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