Stunning Astronomical Alignment Found at Peru Pyramid

An ancient astronomical alignment in southern Peru has been discovered by researchers between a pyramid, two stone lines and the setting sun during the winter solstice. During the solstice, hundreds of years ago, the three would have lined up to frame the pyramid in light.

The two stone lines, called geoglyphs, are located about 1.2 miles (2 kilometers) east-southeast from the pyramid. They run for about 1,640 feet (500 meters), and researchers say the lines were "positioned in such a way as to frame the pyramid as one descended down the valley from the highlands."

Using astronomical software and 3D modeling, the researchers determined that a remarkable event would have occurred during the time of the winter solstice.

"When viewed in 3D models, these lines appear to converge at a point beyond the horizon and frame not only the site of Cerro del Gentil [where the pyramid is], but also the setting sun during the time of the winter solstice," the research team wrote in a poster presentation given recently at the Society for American Archaeology annual meeting in Honolulu.

"Thus someone viewing the sunset from these lines during the winter solstice would have seen the sun setting directly behind, or sinking into, the adobe pyramid," they write. "Thus the pyramid and the linear geoglyph constitute part of a single architectural complex, with potential cosmological significance, that ritualized the entire pampa landscape." (The word "pampa" stands for plain.)

The flattop pyramid is 16 feet (5 m) high and was built sometime between 600 B.C. and 50 B.C., being reoccupied somewhere between A.D. 200 and 400. Finds near the pyramid include textiles, shells and ceramics. The stone lines were constructed at some point between 500 B.C. and A.D. 400.

Lines, settlements and pyramids

But this discovery is just the tip of the proverbial iceberg. Researchers have found about 50 of these stone lines so far in a flat, dry area near the pyramid. The longest of the lines runs for nearly a mile (about 1,500 m). These lines are straight and made out of rock, unlike the Nazca Lines in southern Peru which were etched into the earth by removing the topsoil and include depictions of animals and plants.

Interspersed with these lines, researchers have also found more than 200 cairns (rock piles). The biggest of these cairns is about 50 feet (15 m) in diameter. Cairns can be found throughout the world and sometimes contain human burials, the examples found here, however, do not.

The stone lines and cairns appear to be connected with nearby settlements and their pyramids. There are four ancient settlements close to them, two of which have large pyramids and one that has a mound. The settlements would have supported populations in the high hundreds or just over 1,000.

"Many of the lines do lead to the pyramids; most lead to within the area of the pyramid," said Charles Stanish, a professor at UCLA's Cotsen Institute of Archaeology, in an interview with LiveScience. "We did a statistical analysis, and it is statistically significant— it couldn't have been by random chance that they do cluster on these settlements," he said, noting that there are a few lines that don't lead to settlements.

Stanish said that the discovery of ancient lines leading to pyramids in Peru is important. "We have lines that run to pyramid complexes, and that's significant, because in the big Nazca pampa and in the Palpa pampa, we don't find that pattern as obvious." These two areas, Nazca and Palpa, contain lines, etched in earth, that depict various motifs, including animals and plants.

Future exploration

The team has only completed one field season at the site and will be heading back this summer to continue their work. They plan to excavate at the Cerro del Gentil pyramid and search for more stone lines.

"We're also going to do a systematic survey of a fairly large area to find all the other lines and all the other settlements and features," Stanish said. They also plan to dig test pits in structures associated with the lines to try to determine precisely when they were built.

One problem the team faces is that time is against them. "A lot of them [the stone lines] are being destroyed by construction," said Stanish, explaining that modern-day power and gas lines are being built in the area, jeopardizing the ancient stone lines that have stood for well over a millennia.
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References:

Jarus, Owen. 2013. “Stunning Astronomical Alignment Found at Peru Pyramid”. Live Science. Posted: May 6, 2013. Available online: http://www.livescience.com/29335-astronomical-alignment-found-at-peru-pyramid.html

Ancient Egyptian Calendar Reveals Earliest Record of 'Demon Star'

Ancient Egyptians may have chronicled the flickering of a star known as "the Demon," perhaps the earliest known record of a variable star, astronomers suggest.

The ancient Egyptians wrote calendars that marked lucky and unlucky days. These predictions were based on astronomical and mythological events thought of as influential for everyday life. The best preserved of these calendars is the Cairo Calendar, a papyrus document dating between 1163 and 1271 B.C. The entry for each day is prefaced by three hieroglyphics that indicate either good or bad luck, with the characters often derived from events of mythology.

Astronomers at the University of Helsinki in Finland had previously discovered that some of the fortunate days recurred in a pattern, every 29.6 days. This almost exactly matches the length of the lunar cycle — the time between two full moons. New moons may have been associated with bad luck.

Dimming demon star

The scientists also detected another pattern in the calendar, one that occurred every 2.85 days. Now the researchers suggest this approximately matches regular dimming of Algol, "the Demon Star," which lies approximately 93 light-years away in the constellation Perseus as one of the eyes of Medusa's head. Its name comes from the Arabic phrase, ra's al-ghul, which means "the demon's head."

Algol is the brightest known example of an eclipsing binary system — the large bright member of the system, Beta Persei A, regularly gets eclipsed by the dimmer Beta Persei B. From our point of view, Algol dims by more than a factor of three for 10 hours at a time, dwindling easily seen with the naked eye.

"It seems that the first observation of a variable star was made 3,000 years earlier than was previously thought," said researcher Lauri Jetsu, an astronomer at the University of Helsinki.

The Cairo Calendar describes how Wedjat, the Eye of Horus, regularly transformed from peaceful to raging, with good or bad influences on life. Horus was the patron god of kings in ancient Egypt. [Gallery: Sun Gods and Goddesses]

"The eclipse seems to be linked with the lucky days, because it represents the pacification of the Eye of Horus," researcher Sebastian Porceddu, an astronomer and Egyptologist at the University of Helsinki, told LiveScience. "A bright Eye of Horus meant it is raging and a threat to mankind."

Pinch of salt?

In modern times, Algol actually dims every 2.867 days. The researchers suggest this discrepancy of 0.017 days — about 25 minutes — between ancient Egyptian and modern values for Algol's dimming may be due to changes Algol may have undergone in the past three millennia. Matter is apparently flowing from the dimmer member of this eclipsing binary to the brighter star, altering their orbit so that eclipses now take longer than they once did. If correct, this ancient Egyptian data could shed light on eclipsing binaries and the details of how such mass transfer might affect their orbits.

"I believe that from now on, Egyptologists will be keeping an eye on possible references to Algol elsewhere," Porceddu said.

Other scientists are intrigued by the idea, but remain skeptical.

"I think it's an interesting idea — just how convincing it is is another issue," astrophysicist Peter Eggleton at Lawrence Livermore National Laboratory, who did not take part in this research, said in an interview.

This pattern "does seem very plausibly attributed to Algol, and the suggestion that it has slowed down by a small amount over 3,000 years is not unreasonable," Eggleton said. "But you do have to take the idea with a pinch of salt — it's obviously difficult to pin down what people were really thinking 3,000 years ago."
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References:

Choi, Charles. 2012. "Ancient Egyptian Calendar Reveals Earliest Record of 'Demon Star'". Live Science. Posted: May 31, 2012. Available online: http://www.livescience.com/20575-ancient-egyptian-calendar-demon-star.html

Ancient Egyptians Tracked Eclipsing Binary Star Algol

Turn your telescope to the constellation of Perseus and you might note an unusual star called Algol, dubbed the "Demon Star" or the "Raging One." You wouldn't notice anything much different at first, unless you happened to be looking during a window of a few hours -- every 2.867 days -- when Algol's brightness visibly dims.

This unusual feature was first noticed back in 1667 by an astronomer named Geminiano Montanari, and later confirmed -- with a proposed possible mechanism -- in 1783 by John Goodricke, who precisely measured the period of variability: it dims every 2.867 days.

But a new paper by researchers at the University of Helsinki, Finland, claims that the ancient Egyptians may have recorded Algol's periodic variability 3000 years ago, based on their statistical analysis of a bit of papyrus known as the Cairo Calendar.

This isn't the first time people have hypothesized that Algol's variable nature was known prior to its discovery in the 17th century. Certainly it was a familiar object, prominent in mythology and lore. In the second century, Ptolemy referred to Algol as the "Gorgon of Perseus," and associated it with death by decapitation. (In Greek mythology, the hero Perseus slays the snake-headed Gorgon, Medusa, by chopping off her head.)

Other cultures also associated the star with violence and bad fortune. It's no coincidence that H.P. Lovecraft marked the onset of his final battle in the 1919 short story, "Beyond the Wall of Sleep," with the appearance of a nova near Algol.

But the Helsinki researchers go beyond mythology and conjecture and provide a solid statistical analysis, based on historical documentation.

Goodricke proposed that Algol's periodic variability was due to an eclipsing factor: namely, an orbiting dark body occasionally passed in front of the star, dimming its brightness temporarily.

Alternatively, he suggested that Algol itself had a darker side that turned toward the Earth every 2.687 days.

His hypothesis wouldn't be confirmed until 1881, when Edward Charles Pickering discovered that Algol is actually a binary star system: there were two stars circling together, Algol A and Algol B.

Even more intriguing: it was an "eclipsing binary," i.e., one in which the dimmer star in the system occasionally passes in front of its brighter sibling, dimming the latter according to predictable periods. Goodricke's hypothesis was correct.

Actually, astronomers now know that Algol is a triple-star system, with a third star, Algol C, located a bit further out from the main pair, with a larger orbit.

All of this is necessary background for understanding the conclusions of the Helsinki scientists. The whole point of tracking the heavens so meticulously, for the Egyptians, was to make predictions about the future, dividing the calendar into "lucky" and "unlucky" days. The Cairo Calendar, while badly damaged, nonetheless contains a complete list of such days over a full year, circa 1200 B.C.

How did the Egyptians decide how to rate specific days? That's a mystery. But the Finnish team took the raw data and reassembled it into a tie series, then used statistical techniques to determine the cycles within it. There were two significant periodic cycles. One was 29.6 days, very close to current estimates of a lunar month (29.53059 days).

The second periodic cycle was 2.85 days. Lead author Lauri Jetsu and her colleagues argue that this corresponds to Argol's variable period. It's suspiciously close to the 2.867 period Goodricke measured back in 1783.

Close, yes, but it's not a precise match, which is problematic. The Egyptians weren't known to be sloppy in their astronomical calculations. They should have been able to pinpoint a value much closer to Goodricke's -- unless, say, Algol's period changes over time.

There is some evidence that this might be the case, possibly due to the presence of the third star in the Algol system. Calculating the behavior of a two-body system is one thing; grappling with the dreaded "three-body problem" is quite another, particularly since astronomers are only working with roughly 300 years of data. Algol looks like it's living up to its "Demon Star" moniker.

That's where Jetsu et al's paper might prove to be more than just an intriguing historical oddity. It provides some missing data from 3000 years ago, which could help astronomers further constrain their models for Algol's variable behavior.
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References:

Ouellette, Jennifer. 2012. "Ancient Egyptians Tracked Eclipsing Binary Star Algol". Discovery News. Posted: May 2, 2012. Available online: http://news.discovery.com/space/ancient-egyptians-tracked-eclipsing-binary-star-called-algol-120502.html