The 1054 Supernova Petrograph (Personal Tattoo Dedication)
The Anasazi residents of Chaco Canyon were attentive to the movements of the heavens, that much is clear. The famous Sun Dagger on Fajada Butte in the center of Chaco Canyon is a solar calendar that heralds the winter solstice when a band of sunlight passing through between two slabs intersects the center of a spiral. A square of light floods a notch in the wall of Casa Rinconada’s Great Kiva on the summer solstice, and locations marked within the Great Kiva are thought by some to create a simple stellar observatory.
There are many similar phenomena throughout Chaco Canyon and San Juan basin to the northwest. Sometimes a correlation suggests a dubious conclusion, another might seem obvious. Regardless of the validity of any particular claim, there is little doubt that the Chacoans cared about what happened above them, because there are so many correlations.
On the underside of a shelf below West Mesa in Chaco Canyon, just outside the great house called Peñasco Blanco, is a panel containing three symbols: a large star, a crescent moon, and a handprint.
Halley’s comet made its appearance just a few years after the 1054 supernova. If you were a Chacoan living around this time, you would definitely notice Halley’s comet: its appearance threw many civilized peoples into fear. And since observing the heavens was an important aspect of Chacoan culture, you would probably record it.
Perhaps you would record Halley’s comet where you depicted another one-time astronomical event: below West Mesa, near Peñasco Blanco. Below the star, hand, and moon, in a distinct panel, are three concentric circles, approximately a foot in diameter, with huge red flames trailing to the right. The flames are now so faint that black and white pictures often fail to record it.
Drawing conclusions from these correlations is speculation: we can’t ask the Chacoans why they drew the things they did. But the circumstantial evidence is very strong.
Every 18 1/2 years, the moon and earth return to approximately the same positions they had on July 4, 1054. If you happen to be in Peñasco Blanco around this time, situate yourself with a telescope under that shelf of West Mesa and look up in the sky. Wait until the moon is in a position pointed to by the fingers of the hand. And then use the diagram under the shelf to position your telescope at the large star in the petrograph. Look in your telescope, and you will see the Crab Nebula. And perhaps you will imagine how the Chacoans felt the day a visiting star appeared in their sky.
The Crab Nebula | Messier 1 | SN 1054
When a star dies in a violent, fiery death, it spews its innards out across the sky, creating an expanding wave of gas and dust known as a supernova nebula. Arguably, the most famous of these supernova remnants is M1, also called the Crab Nebula, a blob-like patch visible in low-powered binoculars. Let’s take a look at this viewing treasure.
Chinese astronomers watching the sky on July 4, 1054, noted the appearance of a new or “guest” star just above the southern horn of Taurus. But knowledge of star-fields was not necessary to spot this surprising visitor — according to records, the bright source was visible during the daytime for 23 days, shining six times as brightly as Venus. Those well-versed with the night sky would have been able to see it for 653 days — almost two years — with the naked eye. Other observations of the explosion were recorded by Japanese, Arabic, and Native American stargazers.
In 1731, British astronomer John Bevis observed a cloudy blob in the sky and added it to his star atlas. But it wasn’t until French astronomer Charles Messier independently observed it 27 years later that things began to pick up for this stellar remnant.
Messier was a voracious comet hunter, but he found that the quality of telescopes at the time made it easy to confuse the fuzzy, blazing balls of ice with the hazy nebulae that dot the night sky. While searching for a comet that Edmond Halley had predicted would return in 1758, Messier discovered a hazy patch in the sky, which he would later add to his catalog as Messier 1, or M1. Studying the nebula over time revealed that, unlike a comet, it didn’t move across the night sky, and thus was a completely different feature.
After a few other misidentifications, Messier was determined to put together a catalog of these objects in order to prevent other astronomers from making the same mistake. M1 became his first entry. Although he credited himself with its discovery in his first publication of the Messier catalog, he acknowledged Bevis’ original finding in subsequent versions after receiving a letter from the astronomer. Messier went on to expand his list to include 110 objects, most of them supernova remnants.
Around 1844, British astronomer William Parsons, the third Earl of Rosse, sketched the nebula. The resemblance of the image to a crustacean led to M1’s other name, the Crab Nebula.
In the early 20th century, astronomers were able to take more detailed measurements of M1 and determined that it is expanding. Working backwards, they determined its origination date, and matched the explosion up with observations from Chinese and Native American records.
The guts of the nebula
A supernova remnant forms when the pressure inside of a star is stronger than the gravity that holds it together, and the star explodes. As the gas rushes outward, it fills the space around it. The material ejected from the Crab Nebula is moving at more than 3 million mph (4.8 million kph).
The nebula stretches 10 light-years across, though it continues to expand. It lies approximately 6,300 light-years from Earth, in the constellation of Taurus. M1 can be seen with the naked eye in a dark sky, but only barely. A pair of binoculars will turn up a dim patch, while more of the identifying features of the nebula become visible with a low-magnification telescope. A higher-grade, 16-inch telescope will begin to refine more of the nebula.
A bright source within
In the summer of 1967, U.S. Air Force officer Charles Schisler was on radar duty at Clear Air Force Base in Alaska when he noticed a fluctuating radio source. The source appeared over the course of several days, and Schisler noticed that its position coincided with the Crab Nebula. However, the findings weren’t published by the Air Force at the time, and the discovery went unrealized until 2007.
A year later, astronomers in Puerto Rico discovered the same pulsing radio source. Determined to be a pulsar, the object is a rapidly-rotating, town-sized star that flashes about 30 times a second. Known as NP0532, or the Crab Pulsar, the neutron star is 100,000 times more energetic than the sun. Though only a few tens of miles across, it shines about as brightly as our nearest sun.
A supernova is the explosion of a large star. Our sun is too small to create a supernova. The star that created the Crab Nebula was much bigger. When a supernova occurs, the majority of the matter in the star is blown outward at nearly the speed of light. If you are close, you don’t get to watch it very long before you are blown to bits. If you are far away, it will look like a very bright star, once the light from the explosion has taken its time to reach you.
The star that caused the 1054 supernova is about 4000 light years away, and much of the supernova’s energy had diminished through space before it reached the earth. Nevertheless, on July 4, 1054, 4000 years after the Crab Nebula supernova actually occurred, a star six times brighter than Venus appeared in the sky. It was visible on Earth at high noon, and stayed visible for 23 days. The supernova was so strong that had it occurred within 50 light years of Earth, all living things on the planet might have been destroyed.
HubbleSite Image Tours | Crab Nebula
"Atoms synthesized in the interiors of stars are commonly returned to the interstellar gas. Red giants find their outer atmospheres blowing away into space; planetary nebulae are the final stages of Sunlike stars blowing their tops. Supernovae violently eject much of their stellar mass into space. The atoms returned are, naturally, those most readily made in the thermonuclear reactions in stellar interiors: Hydrogen fuses into helium, helium into carbon, carbon into oxygen and thereafter, in massive stars, by the successive addition of further helium nuclei, neon, magnesium, silicon, sulfur, and so on are built - additions by stages, two protons and two neutrons per stage, all the way to iron. Direct fusion of silicon also generates iron, a pair of silicon atoms, each with twenty-eight protons and neutrons, joining, at a temperature of billions of degrees, to make an atom of iron with fifty-six protons and neutrons.
These are all familiar chemical elements. We recognize their names. Such stellar nuclear reactions do not readily generate erbium, hafnium, dyprosium, praseodymium or yttrium, but rather the elements we know in everyday life, elements returned to the interstellar gas, where they are swept up in a subsequent generation of cloud collapse and star and planet formation. All the elements of the Earth except hydrogen and some helium have been cooked by a kind of stellar alchemy billions of years ago in stars, some of which are today inconspicuous white dwarfs on the other side of the Milky Way Galaxy. The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars…”
Carl Sagan; Cosmos, Chapter IX: The Lives of Stars