Blast from the past: Observatory discovery helps unravel astronomical mystery

November 24, 2020

An international team of astronomers using new observations from the Gemini Observatory have discovered that CK Vulpeculae, first seen as a bright new star in 1670, is approximately five times farther away than previously thought.

This makes the 1670 explosion of CK Vulpeculae much more energetic than previously estimated and puts it into a mysterious class of objects that are too bright to be novae, but too faint to be supernovae. The CK Vulpeculae nebula. The astronomers measured the speeds and changes in positions of the two small reddish arcs about 1/4 of the way up from the bottom and 1/4 of the way down from the top to help determine that the nebula is expanding five times faster than previously thought. Credit: International Gemini Observatory/NOIRLab/NSF/AURA Download Full Image

Almost exactly 350 years ago, the French monk Anthelme Voituret saw a bright new star flare into life in the constellation of Vulpecula. Over the following months, the star became almost as bright as Polaris, known as the North Star, and was monitored by some of the leading astronomers of the day before it faded from view after a year.

The new star eventually gained the name CK Vulpeculae and was long considered to be the first documented example of a nova — a fleeting astronomical event arising from an explosion in a close binary star system in which one member is a white dwarf, a remnant of a sun-like star.

However, a string of recent results has thrown the long-standing classification of CK Vulpeculae as a nova into doubt, including findings recently published in the Astrophysical Journal of the American Astronomical Society with co-author and astrophysicist Sumner Starrfield of Arizona State University.

“The new Gemini observations have shown that they are bipolar lobes and we can use their velocities and improved imaging of their expansion to obtain a new distance of nearly 10,000 light years. This is considerably larger than previously believed,” said Starrfield, who is a Regents Professor with ASU’s School of Earth and Space Exploration. “At this distance, it was much brighter than we thought and in fact was one of the brightest systems in the galaxy for a short time, exceeded only by that of a supernova.”  

This wide-field view shows the sky around the location of the historical exploding star CK Vulpeculae. The remains of the nova are only very faintly visible at the center of this picture. Credit: ESO/Digitized Sky Survey 2.

In 2015, a team of astronomers suggested that CK Vulpeculae’s appearance in 1670 was the result of two normal stars undergoing a cataclysmic collision. Just over three years later, the same astronomers further proposed that one of the stars was in fact a bloated red giant star following their discovery of a radioactive isotope of aluminum in the immediate surroundings of the site of the 1670 explosion.

This chart of the position of a nova (marked in red) that appeared in the year 1670 was recorded by the famous astronomer Hevelius and was published by the Royal Society in England in their journal Philosophical Transactions. Credit: Royal Society

Complicating the picture even further, a separate team of astronomers proposed a different interpretation. In their paper, also published in 2018, they suggested that the sudden brightening in 1670 was the result of the merger between a brown dwarf — a failed star too small to shine via thermonuclear fusion that powers the sun — and a white dwarf.

Now, adding to the ongoing mystery surrounding CK Vulpeculae, new observations from the Gemini Observatory, a program of the National Science Foundation’s NOIRLab, have revealed that this enigmatic astronomical object is much further away and has ejected gas at much higher speeds than previously reported.

The team, led by Dipankar Banerjee of Physical Research Laboratory Ahmedabad, India, Tom Geballe of Gemini Observatory and Nye Evans of Keele University in the United Kingdom, initially planned to use the Gemini Near-Infrared Spectrograph (GNIRS) instrument on Gemini North to confirm the 2018 detection of radioactive aluminum at the heart of CK Vulpeculae. After realizing that detecting this in the infrared would be far more difficult than they originally thought, the astronomers improvised and obtained infrared observations across the full extent of CK Vulpeculae, including the two wisps of nebulosity at its outermost edges.

“The key to our discovery was the GNIRS measurements obtained at the outer edges of the nebula,” Geballe said. “The signature of red-shifted and blue-shifted iron atoms detected there shows that the nebula is expanding much more rapidly than previous observations had suggested.”

As lead author and astronomer at the Physical Research Laboratory in India, Banerjee explained, “We did not suspect that this is what we would find. It was exciting when we found some gas traveling at the unexpectedly high speed of about 7 million km/hour. This hinted at a different story about CK Vulpeculae than what had been theorized.”

By measuring both the speed of the nebula’s expansion and how much the outermost wisps had moved during the last 10 years, and accounting for the tilt of the nebula on the night sky, which had been estimated earlier by others, the team determined that CK Vulpeculae lies approximately 10,000 light- years distant from the sun — about five times as far away as previously thought.

That implies that the 1670 explosion was far brighter, releasing roughly 25 times as much energy than previously estimated. This much larger estimate of the amount of energy released means that whatever event caused the sudden appearance of CK Vulpeculae in 1670 was far more violent than a simple nova.

“This brightness seems to rule out the previously believed idea that it was a merger of a star and a brown dwarf. And there seems to be too much mass of gas and dust in the system to be the result of a merger,” Starrfield said. “Our bottom line is we do not know what caused the outburst as yet. We cannot see through the dust to the underlying object which is still hidden.”

This article was written by the National Science Foundation's NOIRLab communications team with contributions from Karin Valentine with ASU's School of Earth and Space Exploration.

Bountiful harvest celebrations from around the globe

Faculty in ASU's School of Historical, Philosophical and Religious Studies discuss the different religious and cultural backgrounds of harvest holidays

November 24, 2020

Throughout human history, the celebration of a bountiful harvest is weaved into many different cultures. Many of these celebrations are rooted in religious or cultural practices, including the Thanksgiving holiday celebrated in the United States.

Today, harvests are celebrated around the world in different ways and for different reasons. Religious studies faculty in Arizona State University's School of Historical, Philosophical and Religious Studies gave insight on some celebrations from countries around the world. Grain in a field at sunset Photo courtesy of Download Full Image


Sombile is a fall harvest festival on the day of the autumnal equinox that was celebrated by Muslim Turkic-speaking people of the Russian Federation, or Tatars, before the Bolshevik Revolution of 1917. Although many of the prerevolutionary agrarian festivals, such as Sombile, faded away during  Soviet Union rule, the famous Sabantuy festival or the Plough festival remain in practice to this day.

“Currently Sombile is experiencing a comeback, especially in schools,” said Agnes Kefeli, clinical professor of religious studies. “People come from different villages to see children perform in plays that reenact the ancient festival as they imagined it to be in the past. A girl is chosen for her beauty and wit to represent Mother Nature.”

The girl is placed on a throne and people bring fruits of harvest to her. She is then asked to predict whether the winter will be cold or not.

“Because this festival has no Islamic basis, mullahs and female religious teachers, abystays, object to the renewal of this celebration in schools,” Kefeli said. “Nevertheless, many secular Tatar teachers welcome it because it is, in their view, an occasion for the community to speak and sing in Tatar, eat Tatar dishes and renew their commitment to their unique culture.”

Many Tatar people welcome Sombile as an ecological festival that reunites them with nature and their native landscape since many resent the damage caused by forced industrialization. 

Zhongqiu Jie (Middle Autumn Festival)

Zhongqiu Jie, the Middle Autumn Festival or the Moon Festival, is celebrated in China. The Chinese traditionally used the lunar calendar and this festival was timed for the 15th day of the eighth month. 

“The 15th of each month is always a full moon and, as you know, the ‘harvest moon’ is usually gorgeous,” said Regents Professor of religious studies and Chinese Stephen Bokenkamp. “It is also celebrated in Korea and Japan under other names. Chuseok ‘autumn eve’ in Korea and Tsukimi ‘moon viewing’ in Japan.”

This harvest’s earliest recorded celebration dates back to during the Shang dynasty, 1600–1046 BC, but its origin is unknown. Today, the festival is one of the few still based on the lunar calendar, so it falls at a different time each year according to the solar calendar. This year it was on Oct. 1. 

There is a custom of putting out lanterns, viewing the moon and eating moon cakes and other foods based on major crops such as rice and wheat for the festival. Many stories are associated with the festival, including ones of gods, goddesses and emperors.

“My favorite is that, on one moon festival night, the Tang emperor Li Longji asked the Daoist Ye Jingneng where the best lanterns in the kingdom might be situated,” Bokenkamp said. “The Daoist responded, but said that none matched the brilliance of those in the Moon Palace. He then conducted the emperor to the palaces of the moon where he learned the music to the Daoist dance ‘Rainbow Skirts and Feathered Robes’ from the performance of the ‘silk white maidens’ who entertained him there.”

The Celebration of the Coronation of Emperor Haile Selassie I and Empress Menen Asfaw of Ethiopia

Rastafari communities around the world celebrate the coronation date of Emperor Haile Selassie I and Empress Menen Asfaw of Ethiopia on Nov. 2 of every year. The coronation occurred on that date in 1930 and was a monumental moment for the community because Ethiopia was one of the only sovereign nations in Africa at the time.

“The spectacle of a Black king and queen during white supremacist European imperialism was a transformative moment across Africa and the African diaspora,” said Shamara Wyllie Alhassan, assistant professor of religious studies. “This coronation was transformative because it exposed the lie or disinformation campaign that narrated Africa as ahistorical and Africans as inhuman. For Rastafari, the coronation signified Black humanity, Black royalty and Black divinity during a time when Black people desperately needed a symbol of hope.”

The celebration of the coronation is still held in Rastafari communities across the globe. Emperor Haile Selassie I and Empress Menen Asfaw are divine in Rastafari cosmology, which originated with Leonard Percival Howell in his 1935 book, “The Promised Key.”

“A typical celebration looks like a large gathering with singing, drums, sharing food, reasonings or extended debates about several issues pertaining to the world and Rastafari spirituality,” Alhassan said. “The celebration reaffirms community, shared orientation and ideas amongst Rastafari communities.”

Saints Days

There are many harvest holidays celebrated across Eurasia, all beginning at different times and for different reasons but most revolve around the Russian Orthodox Church. 

In Ukraine, the harvest festivities begin on the feast day of the Great Martyr Saint Procopius the Harvester. The Russian Orthodox Church continues to use the Julian calendar, as did Russia from 1700 to 1918.

“Procopius’s feast day falls on July 8 in the Julian calendar, which is July 21 in the Gregorian,” said Eugene Clay, associate professor of religious studies. “The harvesters took the first few ears of grain solemnly to their home, where they placed them beneath a consecrated painted image of a saint or holy event and decorated them with crowns made from flowers. When the grain was milled, these first ears were processed separately so that they could be later mixed with the seeds that would be sown. In this way, the farmers returned fertility to the earth.”

In other places in Russia, the beginning of the harvest is celebrated on Saint Panteleimon’s Day with ears of grain solemnly brought to the church to be blessed.

“Likewise, at the end of the harvest, farmers left a few ears of grain in the field, which they call ‘the beard,’” said Clay. “According to the folklorist Vladimir Propp, people differed over whether these remaining grains represented the beard of St. Elijah, the beard of Christ or even the beard of the landlord. The peasants decorated these unharvested grains with ribbons or flowers and then made an appeal to them to guarantee the fertility of the fields.”

Andean Harvest Fiestas

Unlike most monotheistic harvest traditions, where there is a god who created crops and the Earth from outside of itself and therefore there is an abundance of resources, many native and Indigenous people view the Earth as something that needs to be replenished and thanked directly. This is true for people who are native to the Andes in South America. 

“The mountains in the Andes are thought of as being reservoirs or storehouses of every good thing,” said Tod Swanson, associate professor of religious studies. “But they are like a human body. They are like human beings in the sense that they can wear out; they can be exhausted.”

The Andean harvest festivals take place around the winter solstice, which south of the equator is around June. People from neighboring communities from up and down the mountains come together for days of feasting, drinking and dancing. 

The primary purpose of the festival is to elicit a reaction from the mountains to bring liquid rain so the next cycle of crops will grow. In these traditions, the fluids that come from the earth are thought of as emotional, bodily and sexual fluids such as tears or milk. 

“The idea here is that the mountains that are up around the earth are flowing water down to nourish the people,” Swanson said. “The idea here is that the people that are having the festival are the children of the mountains and the ancestors are inside those mountains and on the Earth.”

These festivals last days as people eat and drink alcohol. They also pour their drinks out on the ground, so that they are sharing their harvest with their ancestors and the earth.

“You are engaging the earth that is tied into your body through a circulation of fluids,” Swanson said. “It is somehow tied into you and you are, not paying the earth, but you are flirting with the earth or engaging the earth so as to create a response of love.”

Now, the harvest fiestas have become attached to different Catholic feast days, but remain an important celebration in the regions. 


Sukkoth is the final harvest festival for Jewish people all over the world. It’s also known as Feast of Tabernacles or the Festival of Booths and commemorates God protecting the Israelites during their desert wanderings.

“It originates in the Hebrew Bible and is one of three pilgrimage festivals, along with Passover and Shavuot, when Jews would make pilgrimage to the Jerusalem temple with offerings,” said Timothy Langille, lecturer of religious studies. “For Sukkoth, that offering would be from the autumn harvest. Before the second temple was destroyed in 70 CE by the Romans, Sukkoth also was a water-drawing festival when libations would be poured over the altar as people prayed for rain.”

As part of the celebration, as prescribed by the Torah, people build a “sukkah,” also known as a booth or temporary shelter, as a reminder that the Israelites lived in sukkahs after the exodus from Egypt. 

“These structures are built in yards, gardens or balconies and it’s customary to dwell in them,” Langille said. “The roof of the sukkah is covered with branches and plants and is decorated in various other ways, but the stars at night can be seen through the roof. If possible, meals during Sukkoth are eaten in the sukkah.”

This harvest is an eight-day festival for Jewish people in the diaspora and a seven-day festival for Jews living in Israel and it begins five days after Yom Kippur, the holiest of days on the Jewish calendar. Like an American Thanksgiving, Jewish people will use a cornucopia as a symbol of the holiday, but the holiday is also associated with palm, myrtle, willow and citron.

Rachel Bunning

Communications program coordinator, School of Historical, Philosophical and Religious Studies