Hubble Does Independence Day With Stars and Stripe

By Nancy Atkinson - July 1, 2008 at 9:30 AM UTC | Stars
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Back in 1006 A.D, observers from Africa to Europe to the Far East witnessed and recorded the arrival of light from what is now called SN 1006, a tremendous supernova explosion caused by the final death throes of a white dwarf star nearly 7,000 light-years away. One Egyptian astronomer recorded the object was 2 - 3 times as large as the disc of Venus and about one quarter the brightness of the moon. The supernova was probably the brightest star ever seen by humans, visible even during the day for weeks, and it remained visible to the naked eye for at least two and a half years before fading away. Remnants of this supernova are still visible to telescopes, and the Hubble Space Telescope captured this close-up a filament of the shock wave of the explosion, still reverberating through space, seen here against the grid of background stars. The full image of SN 1006 is pretty impressive, too…

SN 1006 has a diameter of nearly 60 light-years, and it is still expanding at roughly 6 million miles per hour. Even at this tremendous speed, however, it takes observations typically separated by years to see significant outward motion of the shock wave against the grid of background stars. In the Hubble image shown here, the supernova would have occurred far off the lower right corner of the image, and the motion would be toward the upper left.

It wasn't until the mid-1960s that radio astronomers first detected a nearly circular ring of material at the recorded position of the supernova. The ring was almost 30 arcminutes across, the same angular diameter as the full moon. The size of the remnant implied that the blast wave from the supernova had expanded at nearly 20 million miles per hour over the nearly 1,000 years since the explosion occurred.

In 1976, the first detection of exceedingly faint optical emission of the supernova remnant was reported, but only for a filament located on the northwest edge of the radio ring. A tiny portion of this filament is revealed in detail by the Hubble observation. The twisting ribbon of light seen by Hubble corresponds to locations where the expanding blast wave from the supernova is now sweeping into very tenuous surrounding gas.

The hydrogen gas heated by this fast shock wave emits radiation in visible light. Hence, the optical emission provides astronomers with a detailed "snapshot" of the actual position and geometry of the shock front at any given time. Bright edges within the ribbon correspond to places where the shock wave is seen exactly edge on to our line of sight.

Original News Source:

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Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com