X-ray image of the remnants of SN 1006. Image Credit: Wikimedia Commons // Public Domain
X-ray image of the remnants of SN 1006. Image Credit: Wikimedia Commons // Public Domain

Medieval Supernova Lit Earth’s Skies for Months

X-ray image of the remnants of SN 1006. Image Credit: Wikimedia Commons // Public Domain
X-ray image of the remnants of SN 1006. Image Credit: Wikimedia Commons // Public Domain

We modern folks love our supermoons, meteor showers, and planetary sightings. But citizens of 11th-century Earth had something even better: their own supernova.

Witnessed from Earth on April 30–May 1, 1006, the massive stellar explosion was—and still is—the brightest supernova in recorded history. Its light blanketed Earth for months, and may have been strong enough to read by. Today we call it SN 1006, but at the time nobody knew quite what to make of it.

Benedictine monks in Switzerland wrote of a star “glittering in aspect and dazzling the eyes, causing alarm.” Their brothers in Italy were less effusive, reporting simply that “a brilliant star gleamed forth.”

Egyptian physician and astronomer Ali ibn Ridwan wrote that “the sky was shining.” He calculated the supernova’s brightness as three times that of Venus. Observers in Iraq marveled at the star’s “dazzling rays.”


Rock carvings by the Hohokam people may depict the 1006 supernova. Image credit: John Barentine, Apache Point Observatory

Some modern astronomers believe early Native American people also documented the cosmic event. Carvings found on a rock in Arizona seem to illustrate both the supernova and its position in the sky. 

The more precise records of the explosion come from medieval Japan and China, where astronomers watched the skies with unmatched rigor and precision. Japanese observers called SN 1006 the “guest star” and described it as “like Mars … bright and scintillating.”

Nine separate Chinese accounts of the supernova attest to the intensity of its light. One source said it was so bright “one could scrutinize things.” 

Supernovae are the biggest explosions in space, and can out-dazzle entire galaxies. They’re also the main source of heavy elements in the universe. When Carl Sagan famously said that we’re all made of “star stuff,” he was talking about the remains of SN 1006 and its kin.

The light show in 1006 was likely the consequence of a cosmic merger between two white dwarf stars. Each star was the size of a planet and had as much mass as the Sun. It's no wonder the explosion was so magnificent.

Just how bright was it? Pretty dang bright. In 2003, Frank Winkler of Middlebury College combined what was known about the explosion itself with recent measurements of the star’s chemical remains. At the explosion’s peak, Winkler concluded, “people could probably have read manuscripts at midnight by its light.”

Nobody had ever seen anything like it before, and nobody has since. The last time a supernova was visible from Earth without a telescope was 1604. That explosion was nothing compared to SN 1006. 

It’s not that supernova explosions are a rare event. Far from it: A star explodes somewhere in the universe once every second. Everything is exploding, all the time. Our universe is just so big that we almost never notice. 

ESO, A. Müller et al.
Here's the First Confirmed Image of a Planet Being Born
ESO, A. Müller et al.
ESO, A. Müller et al.

One of the newest landmarks in the observable universe has finally been captured, according to the European Southern Observatory. The image, snapped at its Very Large Telescope (VLT) in Chile, marks the first time a newborn planet has been seen as it forms. 

The image was documented by SPHERE, an instrument at the VLT that's built to identify exoplanets. It shows a planet, dubbed PDS 70b, taking shape in the disc of gas and star dust surrounding the young dwarf star PDS 70. In the past, astronomers have caught glimpses of what may have been new planets forming, but until now it had been impossible to tell whether such images just showed shapes in the dust or the beginnings of true planet formation. The results of the research will be shared in the journal Astronomy & Astrophysics [PDF].

This latest cornograph (an image that blocks the light of a star to make its surroundings visible) depicts the new planet clearly as a bright blob beside the black star. The two bodies may look close in the photo, but PDS 70b is roughly 1.8 billion miles from PDS 70, or the distance of Uranus to the Sun. SPHERE also recorded the planet's brightness at different wavelengths. Based on information gathered from the instrument, a team of scientists led by Miriam Keppler of the Max Planck Institute for Astronomy says that PDS 70b is a gas giant a few times the mass of Jupiter with a surface temperature around 1830°F and a cloudy atmosphere.

Astronomers known that planets form from solar clouds which stars leave behind when they come into a being, but until now, the details surrounding the phenomena have been mysterious. “Keppler’s results give us a new window onto the complex and poorly understood early stages of planetary evolution,” astronomer André Müller said in a press release. “We needed to observe a planet in a young star’s disc to really understand the processes behind planet formation.”

This is just the latest history-making image captured by the ESO's Very Large Telescope. In the last 20 years, it has documented nebulae, light from gravitational waves, and interacting galaxies.

Saturn and a Strawberry Moon Will Brighten Night Skies This Week

Summer has officially arrived. That means the weather is finally warm enough in parts of the country to lay down a blanket in your backyard and spend the night staring at the sky. This week is especially exciting for stargazers. According to Mashable, Saturn will be visible in the sky beside a "strawberry moon."

One of the first major celestial events of the season takes place Wednesday, June 27. The Earth will fall directly between Saturn and the Sun on Wednesday and a brightly shining Saturn will be visible in the eastern sky after the Sun goes down. The best time to spot the ringed planet is around midnight, and it will appear in the sky for the next several months.

On Wednesday, when Saturn is at its brightest, the sky will present another treat. A full strawberry moon will rise not far from Saturn's spot around 12:53 a.m. EDT that night and accompany the planet as it moves across the sky. The name isn't a reference to the Moon's hue, but to the time of year when it appears: A strawberry moon is the first full moon of summer, and it was once used by farmers to mark the beginning of strawberry picking season.

These two events are just the start of a promising time of year for astronomy fans. Sync your digital planner to this space calendar so you don't miss out on any other big dates, like the partial solar eclipse on August 11.

[h/t Mashable]


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