Scientists at Penn State have created a breath-based sensor that detects diabetes by measuring acetone levels. The quick, non-invasive test could transform how the disease is diagnosed and managed. Credit: Stock
A Penn State team created a breath sensor that identifies diabetes by detecting acetone. The device is fast, non-invasive, and built with laser-induced graphene for precision.
In the United States, nearly one in five of the 37 million adults living with diabetes is unaware of their condition. Standard methods for diagnosing diabetes and prediabetes often involve clinic visits and laboratory tests, which can be both costly and time-consuming. Researchers now suggest that detection may soon be as simple as analyzing a person’s breath.
A team led by Huanyu “Larry” Cheng, the James L. Henderson, Jr. Memorial Associate Professor of Engineering Science and Mechanics at Penn State, has created a sensor capable of diagnosing diabetes and prediabetes within minutes using only a breath sample. Their findings were recently reported in Chemical Engineering Journal.
Acetone as a biomarker for diabetes
Traditional diagnostic approaches have typically relied on measuring glucose levels in blood or sweat. This new sensor, however, focuses on acetone in exhaled breath. Although acetone is naturally present as a byproduct of fat metabolism, levels higher than approximately 1.8 parts per million are a strong indicator of diabetes.
“While we have sensors that can detect glucose in sweat, these require that we induce sweat through exercise, chemicals, or a sauna, which are not always practical or convenient,” Cheng said. “This sensor only requires that you exhale into a bag, dip the sensor in, and wait a few minutes for results.”
Cheng noted that previous breath-analysis devices often targeted biomarkers that still required laboratory confirmation. In contrast, this new design enables on-site detection of acetone, making it both practical and affordable.
Designing a selective and efficient sensor
Beyond identifying acetone as the target biomarker, Cheng emphasized that the innovation also lies in the sensor’s construction and materials—particularly the use of laser-induced graphene. This material is produced when a carbon-based substrate, such as polyimide film, is exposed to a CO₂ laser, which transforms it into a patterned, porous graphene with defects that make it highly effective for sensing applications.
“This is similar to toasting bread to carbon black if toasted too long,” Cheng said. “By tuning the laser parameters such as power and speed, we can toast polyimide into few-layered, porous graphene form.”
A team led by a researcher at Penn State has developed a sensor that can help diagnose diabetes and prediabetes on-site in a few minutes using just a breath sample. Credit: Larry Cheng/Penn State
The researchers used laser-induced graphene because it is highly porous, meaning it lets gas through. This quality leads to a greater chance of capturing the gas molecule, since breath exhalation contains a relatively high concentration of moisture. However, by itself, the laser-induced graphene was not selective enough of acetone over other gases and needed to be combined with zinc oxide.
“A junction formed between these two materials that allowed for greater selective detection of acetone as opposed to other molecules,” Cheng said.
Overcoming challenges and future directions
Cheng said another challenge was that the sensor surface could also absorb water molecules, and because breath is humid, the water molecules could compete with the target acetone molecule. To address this, the researchers introduced a selective membrane, or moisture barrier layer, that could block water but allow the acetone to permeate the layer.
Cheng said that right now, the method requires that a person breathe directly into a bag to avoid interference from factors such as airflow in the ambient environment. The next step is to improve the sensor so that it can be used directly under the nose or attached to the inside of a mask, since the gas can be detected in the condensation of the exhaled breath. He said he also plans to investigate how an acetone-detecting breath sensor could be used to optimize health initiatives for individuals.
“If we could better understand how acetone levels in the breath change with diet and exercise, in the same way we see fluctuations in glucose levels depending on when and what a person eats, it would be a very exciting opportunity to use this for health applications beyond diagnosing diabetes,” Cheng said.
Reference: “ZnO/LIG nanocomposites to detect acetone gas at room temperature with high sensitivity and low detection limit” by Li Yang, Wenyuan Fu, Ya Wang, Zhida Wang, Longbiao Mao, Luxiang Xu, Chengpeng Yao, Hongyu Zhang, Sisi Chen, Hui Zhang and Huanyu Cheng, 13 June 2025, Chemical Engineering Journal. DOI: 10.1016/j.cej.2025.164857
Funding from the U.S. National Institutes of Health and the U.S. National Science Foundation supported the Penn State contributions to this work.
Relay Station, an unmanned weather station in the interior of East Antarctica. Unmanned stations are designed to survive Antarctic temperatures below -70°C and have revealed the main cause of warming in East Antarctica’s interior. Credit: Naoyuki Kurita, Nagoya University
East Antarctica’s interior is warming at a startling pace, powered by shifting ocean conditions that drive warm air inland. Long overlooked, this icy heart may hold the key to future sea level rise.
East Antarctica’s Hidden Warming Trend
Scientists have discovered that the deep interior of East Antarctica is warming more quickly than its coastal regions, and they now know why. A 30-year investigation published in Nature Communications, led by Naoyuki Kurita of Nagoya University, traced the cause to shifts in the Southern Indian Ocean that send more warm air into the continent’s center. East Antarctica, long considered an observational “blind spot,” holds the majority of the planet’s glacial ice. This newly uncovered process suggests that current climate projections may be underestimating how fast Antarctic ice could be lost in the future.
Professor Naoyuki Kurita at Dome Fuji Station, East Antarctica, where weather instruments collect climate data year-round. Credit: Naoyuki Kurita, Nagoya University
Collecting Data in Earth’s Harshest Environment
Antarctica is the coldest, driest, and windiest place on Earth, storing around 70% of the world’s freshwater in its immense ice sheets. Until now, most climate records from the region came from manned research stations situated along the coast. The continent’s interior has only four staffed bases, and only two of them provide long-term climate data: Amundsen-Scott Station (South Pole) and Vostok Station (East Antarctic Interior). As a result, much of what happens across the interior has remained poorly documented.
To address this gap, researchers turned to three unmanned weather stations in East Antarctica that have been running since the 1990s: Dome Fuji Station, Relay Station, and Mizuho Station. Using their records, the team created a monthly average temperature dataset spanning 1993 to 2022, providing scientists with the clearest view yet of how the continent’s hidden interior is changing.
A specialized tracked transport vehicle crossing East Antarctica’s ice sheet to reach remote interior research stations. Credit: Naoyuki Kurita, Nagoya University
Why Current Climate Models Fall Short
Annual average temperature changes showed that all three locations experienced temperature increases at a rate of 0.45-0.72°C per decade, faster than the global average. The researchers analyzed meteorological and oceanic data and traced this temperature rise to changes in the Southern Indian Ocean that alter atmospheric circulation patterns and transport warm air toward Antarctica’s interior.
Current climate models do not capture this warming process, so future projections of temperature for Antarctica may be underestimated. “While interior regions show rapid warming, coastal stations have not yet experienced statistically significant warming trends,” Professor Naoyuki Kurita from the Institute for Space-Earth Environmental Research at Nagoya University said. “However, the intensified warm air flow over 30 years suggests that detectable warming and surface melting could reach coastal areas like Syowa Station soon.”
Professor Naoyuki Kurita at Dome Fuji Station, East Antarctica, where weather instruments collect climate data year-round. Credit: Naoyuki Kurita, Nagoya University
The Southern Indian Ocean–East Antarctica Link
Ocean fronts—areas where warm and cold ocean waters meet—create sharp temperature boundaries in the Southern Indian Ocean. Because global warming heats ocean waters unevenly, it intensifies these temperature differences: stronger oceanic fronts lead to more storm activity and atmospheric changes that create a “dipole” pattern, with low pressure systems in mid-latitudes and high pressure over Antarctica. The high-pressure system over Antarctica pulls warm air southward and carries it deep into the continent.
Now, for the first time, scientists have comprehensive weather station data demonstrating that East Antarctica’s interior is warming faster than its coasts and have identified the major cause of this change. The study provides important insights into how quickly the world’s largest ice reservoir will respond to continued global warming.
Reference: “Summer warming in the East Antarctic interior triggered by southern Indian Ocean warming” by Naoyuki Kurita, David H. Bromwich, Takao Kameda, Hideaki Motoyama, Naohiko Hirasawa, David E. Mikolajczyk, Linda M. Keller and Matthew A. Lazzara, 22 July 2025, Nature Communications. DOI: 10.1038/s41467-025-61919-3
A unique Roman oil lamp in the shape of a theatrical mask has been discovered in Cuijk, the Netherlands. It dates to the 2nd century A.D. and is complete and in excellent condition.
The lamp is elaborately decorated with botanical motifs, with a large headdress-like acanthus leaf springing from a scallop shell on the forehead of the wide-eyed and even wider-mouthed mask. The sides of the face are framed in curls and what may be two small animal ears. His nose and heavy brow suggest it may be a satyr mask. The mouth serves as the filling hole of the lamp. The “neck” underneath it (actually the nozzle of the lamp) is edged with a fluted border that narrows and then widens again around the wick aperture.
Inspired by the expressive character masks of Greek theater, theatrical masks were common decorative motifs in architecture, art, gravestones and even on everyday utilitarian objects like oil lamps. Lamps with mask motifs are well-known in the Roman world, and when placed in the graves of the deceased, they took on the symbolic role of lighting their way to the underworld. This example is unusually elaborate, however, with its ornate decoration and detailed relief integrated into the shape of the lamp itself. The more typical mask lamp features lamps or actors and masks carved in relief onto the discus of the lamp (the circular top surrounding the filling hole).
It was discovered in the excavation of what has proven to be the largest Roman cemetery in North Brabant. Only an estimated 15% of the burial ground has been explored, and so far more than 85 graves have been unearthed, many of them containing significant goods, including handled jugs, clay plates, glass bottles and jewelry. The reddish plates are terra sigillata, aka samian ware, a type of fine pottery with a flossy glaze made of iron-rich clay in Gaul. The unglazed white vessels were of Germanic production.
Square pits dot the ground, some of them with the tell-tale black stains of carbonization from cremations. Archaeologists found a large number of potsherds, evidence that while the bodies were burning, mourners threw offerings in vases and jugs into the fire. The pottery exploded from the heat and the organic offerings were consumed.
The modern town of Cuijk was the Roman settlement of Ceuclum in antiquity. The large quantities of pottery discovered in the cemetery confirms that the population had wide access to consumer goods imported from elsewhere in the Roman Empire.
This video captures the moment of discovery and how the lamp reveals itself in increasingly complex detail as the archaeologist brushes away the dirt.
1915 Andrew L. Harris, American Civil War hero and Governor of Ohio (1906-09), dies at 79
1921 Louis of Battenberg [Mountbatten], Austrian-born British admiral (WWI), dies at 67
1924 (Pekka) P. J. Hannikainen, Finnish composer, choral director, and music magazine editor (Säveleitä), dies at 69
1928 Italo Svevo [Ettore Schmitz], Italian writer (La Coscienza di Zeno), dies at 66
Danish transgender woman, former painter, and 1st identifiable recipient of sex reassignment surgery (autobiography: Man into Woman), dies from complications involving a uterus transplant at 48
1932 Julius Röntgen, German-Dutch composer, dies at 77
1932 Paul Gorguloff, Russian murderer of French President Paul Doumer, beheaded at 37
1937 Ellis Parker Butler, American author (Pigs is Pigs), dies at 67
1938 Samuel Alexander, English philosopher (Space, time & deity), dies at 79
1939 Eugene Foss, American politician (45th Governor of Massachusetts), dies at 80
1941 Elias Disney, Canadian-American construction worker, entrepreneur, and father of Roy and Walt Disney, dies at 82
1944 Noor Inayat Khan, Indian princess and Special Operations Executive agent in WWII posthumously awarded the George Cross, executed at Dachau at 30
1944 W. Heath Robinson, English illustrator and cartoonist (Don Quixote), dies at 72
1948 Paul Wegener, German actor and director (The Golem, The Student of Prague), dies at 73
Danish zoophysiologist (Nobel Prize in Physiology or Medicine, 1920 for study of arterioles and capillaries), dies at 74 [1]
1950 Sara Allgood, Irish-American stage and screen actress (Peg o’ My Heart; Blackmail; How Green Was My Valley), dies of a heart attack at 69
1959 Gilbert Adrian [Greenberg], American costume designer (The Wizard of Oz), dies of a heart attack at 56
1960 Leó Weiner, Hungarian composer (Toldi), and music educator (Budapest Academy of Music, 1912-60), dies at 75
1965 Jean B. Fletcher, American architect (TAC, the Architects’ Collaborative), dies of cancer at 50
1967 Russell L. Rogers, American electrical engineer and astronaut (X-20), dies in explosion at 39
1967 Varian Fry, American journalist and recognized as “Righteous Among the Nations”, dies at 59
1969 Charles Foulkes, Canada general and honorary citizen of Wageningen who accepted WWII Germany’s surrender in the Netherlands, dies at 66
1971 Lin Biao, Chinese Communist Marshal during the Civil War and party leader, dies in a plane crash at 63, possibly while fleeing from a botched coup against Mao
1971 Nelly A “Nell” Knoop, Dutch actress (Silent Waters), dies at 72
1971 Paul Blackburn, American poet, and editor (Black Mountain Review), dies of esophageal cancer at 44 [1]
1973 Betty Field, American actress (Of Mice and Men; Kings Row; Bus Stop), dies of cerebral hemorrhage at 57
1976 Albert Tessier, French Canadian priest, historian and filmmaker (b. 1895)
1976 Armand Mondou, French Canadian ice hockey player (b. 1905)
1977 Arthur Fagg, English cricket batsman (5 Tests; dual double-centuries for Kent v Essex 1938) and umpire (18 Tests, 7 ODIs), dies at 62
1977 Leopold Stokowski, British conductor (Philadelphia Orchestra, 1912-39; Disney’s Fantasia), dies of a heart attack at 95
1981 William Loeb III, American publisher of Manchester Union Leader, NH, dies at 75
1982 Philip Ober, American actor (North by Northwest), dies at 80
1982 Ray Carter, American orchestra leader (Arthur Murray Dance Party), dies at 73
1985 Dane Rudhyar [Daniel Chennevière], French-American composer, author, and astrologist dies at 90
1987 Mervyn LeRoy, American movie producer (Devil at 4 O’Clock), dies at 86
1989 Yamada Koun, Zen teacher Sanbo Kyodan line, dies at 82
1990 Samuel S. Stratton, American politician (Member of the U.S. House of Representatives from New York), dies at 73
1991 Ferry Barendse, Dutch trumpeter, composer, and singer (Ramblers), dies at 80
1991 Joe Pasternak, Hungarian-American film producer (Spinout, Big City), dies of Parkinson’s at 73
1991 Metin Oktay, Turkish football player (b. 1936)
1991 Paul Thompson, Canadian ice hockey forward (Stanley Cup 1928 NY Rangers; 1934, 38 Chicago Black Hawks), and coach (Chicago BHs 1938-45), dies at 84
1992 Lou Jacobs, US clown (1966 US postage stamp), dies at 89
1994 John Stevens, British jazz drummer (Spontaneous Music Ensemble), dies of a heart attack at 54
1994 Kaleria Fadicheva, Russian ballerina (Kirov) and choreographer, dies at 58 [1]
1994 Pieter Zaanen, Dutch architect (Musical Trade scholarship, Amsterdam), dies at 63
1995 Francesco Messina, Italian sculptor, dies at 94
1995 Harold Sheperdson, British soccer trainer, dies at 76
1995 Walter Goetz, German-British illustrator, cartoonist and painter (Colonel Up and Mr. Down), dies at 83
1996 Anthony Nicholas Maria Wahl, American historian, dies at 68
1996 Cesar Mendoza, general of Military junta of Chile (1973-85), dies at 78
1996 Jane Baxter, British actress (We Live Again, Blossom Time), dies at 87
1996 Silas Roy Crain, American singer, Founder of Soul Stirrers Gospel Quartet, dies at 85
American rapper and actor (Juice, Bullet), dies of internal bleeding after a drive-by shooting at 25
American politician (Gov-D-Ala) and presidential candidate, dies of septic shock at 79
1998 Harry Lumley, Canadian ice hockey player (b. 1926)
1999 Benjamin Bloom, American educational theorist (b. 1913)
2001 Dorothy McGuire, American actress (Gentlemen’s Agreement, Old Yeller, Summer Magic), dies of cardiac arrest following a short illness at 85
Czech ice hockey player (Olympic silver 1948) and tennis player (Wimbledon 1954, French Open 1951-52), dies of a stroke at 79
2002 Douglas Black, Scottish physician and medical scientist (played a key role in the development of the National Health Service), dies at 89
2003 Frank O’Bannon, American politician (Governor of Indiana, 1997-2003), dies of a stroke at 73(
2004 Luis E. Miramontes, Mexican chemist and co-inventor of the combined oral contraceptive pill, dies at 79
2005 Hans Joachim Koellreutter, German Brazilian composer, teacher and musicologist, dies at 90
2005 Julio César Turbay Ayala, Colombian politician (b. 1916)
2005 Toni Fritsch, Austrian soccer forward (9 caps; Rapid Vienna) and American football kicker (Super Bowl 1971 Dallas Cowboys; Pro Bowl 1979), dies of heart failure at 60
2006 Ann Richards, American politician (46th Governor of Texas 1991-95), dies at 73
2007 Clare Oliver, Chinese-Australian cancer activist, campaigned against use of solariums, dies of melanoma at 26
2007 Neville Jeffress, Australian founder of Media Monitors Australia, dies at 87
2007 Whakahuihui Vercoe, New Zealand Anglican clergyman (Archbishop of New Zealand, 2004-06; Bishop of Aotearoa, 1981-2004), and Māori rights advocate, dies of cancer at 79
2009 Paul Burke, American actor (Naked City, Thomas Crown Affair, Neal-Dynasty), dies at 83
2011 DJ Mehdi [Favéris-Essadi], French hip hop and electro producer, dies from falling through a skylight at his home at 34
2011 Walter Bonatti, Italian climber (b. 1930)
2012 Peter Lougheed, Canadian politician (10th Premier of Alberta), dies at 84
2012 William Duckworth, American composer (Time Curve Preludes), teacher (Bucknell, 1973-2011), and internet pioneer (PitchWeb), dies of pancreatic cancer at 69
2013 Bayani Mendoza de Leon, Filipino-American musician and composer (Batong-Buhay), dies at 70
2013 James Bradford, American heavyweight weightlifter (Olympic silver 1952, 56), dies at 84
2015 Brian Close, English cricketer (played for England between 1949 & 1976), dies at 84
2015 Gary Richrath, American guitarist and songwriter (REO Speedwagon), dies at 65
Basketball Hall of Fame center (NBA MVP 1979, 82-83; NBA Finals MVP 1983; 12 x NBA All Star; Houston Rockets, Philadelphia 76ers), dies of heart disease at 60
2017 Frank Vincent, American actor (The Sopranos), dies of a heart attack at 80
2017 Grant Hart, American punk rock drummer and songwriter (Hüsker Dü), dies of liver cancer at 56
2017 Pete Domenici, American politician, U.S. Senator from New Mexico (1973-2009), dies at 85
1087 John II Komnenos, Emperor of the Byzantine Empire (1118-43), born in Constantinople, Byzantine Empire (d. 1143)
1157 Alexander Neckam, English theologist and encyclopedist, born in St. Albans, Hertfordshire, England (d. 1217)
1475 Cesare Borgia, Duke of Valentinois, Italian aristocrat, born in Rome, Papal States (d. 1507)
1502 John Leland, English poet and antiquarian, born in London (d. 1552)
1520 William Cecil, 1st baron Burghley, English statesman, born in Bourne, Lincolnshire, England (d. 1598)
1551 Pandolfo Zallamella, Italian composer (Ingrediente Domino), born in Ravenna, Papal States (d. 1590)
1594 Francesco Manelli, Roman Baroque composer, born in Tivoli, Papal States (d. 1667)
1604 William Brereton, 1st Baronet, English soldier and politician, born in Brereton Hall, Cheshire, England (d. 1661)
English novelist (Robinson Crusoe), born in London, England
1673 Hercule Brehy, Flemish composer and organist, born in Brussels, Spanish Netherlands (d. 1737)
1676 Élisabeth Charlotte d’Orléans, Duchess of Lorraine, born in Château de Saint-Cloud, France (d. 1744)
1682 Theodor Christlieb Reinhold, German composer, born in Eppendorf, Electorate of Saxony, Holy Roman Empire (d. 1755)
1688 Luca Antonio Predieri, Italian composer and violinist, born in Bologna, Papal States (d. 1767)
French admiral who commanded the French fleet at the Battle of the Chesapeake, born in Le Bar-sur-Loup, France
1739 Giuseppe Sigismondo, Italian historian and composer, born in Naples, Kingdom of Naples (d. 1826)
1751 Henry Kobell, Dutch painter and cartoonist, born in Rotterdam, Netherlands (d. 1779)
1755 Oliver Evans, American inventor who pioneered high-pressure steam engine, born in Newport, Delaware (d. 1819)
1766 Samuel Wilson, American meat packer and possible namesake of Uncle Sam, born in Menotomy, Province of Massachusetts Bay (d. 1854)
Canadian heroine of the war of 1812, born in Great Barrington, Massachusetts Bay
1802 Arnold Ruge, German political philosopher and writer, born in Bergen auf Rügen, Germany (d. 1880)
1806 Joseph L. Hogg, American Brigadier General (Confederate Army), born in Morgan County, Georgia (d. 1862)
1806 Moritz Ganz, German composer and cellist, born in Mainz, Grand Duchy of Hesse, Confederation of the Rhine (d. 1868)
1813 John Sedgwick, American Major General (Union Army), who is best remembered for his famous last words “they couldn’t hit an elephant at this distance” before being shot in battle, born in Cornwall, Connecticut (d. 1864)
1814 Nicolas Beets [Hildebrand], Dutch writer (Camera Obscura) and theologian, born in Haarlem, Netherlands (d. 1903)
1817 John M. Palmer, American politician (U.S. Senator from Illinois) and American Civil War General (Union), born in Eagle Creek, Kentucky (d. 1900)
1818 Gustave Aimard, French world explorer and writer (Grande Flibuste), born in Paris (d. 1883)
German pianist and composer of the Romantic era, born in Leipzig, Kingdom of Saxony
1830 Marie von Ebner-Eschenbach, Austrian writer (The Child of the Parish), born in Zdislavič, Moravia (d. 1916)
1831 Andrew Noble, Scottish physicist who was a founder of the science of ballistics, born in Greenock (d. 1915)
1836 John McCausland, American Brigadier General (Confederate Army), born in St. Louis, Missouri (d. 1927)
1841 Johannes de Koo, Dutch journalist and playwright, born in Middelie, Netherlands (d. 1909)
1842 John H. Bankhead, U.S. Senator from Alabama, born in Moscow, Marion County, Alabama (d. 1920)
1842 Ödön Mihalovich, Hungarian composer, born in Fericsánci, Slavonia (d. 1929)
1846 Richard Kiepert, German cartographer (Africa), born in Weimar, Germany (d. 1915)
1847 Charles Dupee Blake, American composer, born in Walpole, Massachusetts (d. 1903)
1851 Walter Reed, U.S. Army physician and bacteriologist who proved mosquitoes transmit yellow fever, born in Belroi, Virginia (d. 1902)
1853 Sophia Perovskaya, Soviet icon, aristocrat, and socialist revolutionary (Narodnaya Volya), who helped orchestrate the successful assassination of Alexander II of Russia, born in Saint Petersburg, Russian Empire (d. 1881)
1855 Jacobus van Looy, Dutch writer (Jaapje; De Dood van mijn Poes (The Death of My Cat) ) and painter (Witte poes in een open raam (White Cat in an Open Window)), born in Haarlem, Netherlands (d. 1930)
1857 Michał Drzymała, Polish peasant rebel (Drzymała’s wagon), born in Province of Posen, Poland (d. 1937)
American chocolate tycoon (The Hershey Chocolate Company) and philanthropist, born in Derry Township, Pennsylvania
1858 Catherinus Elling, Norwegian organist, composer, educator, and ethnomusicologist, born in Christiania, Norway (d. 1942)
American army general and World War I commander known as “Black Jack”, born in Laclede, Missouri
1862 Dirk Bos, Dutch Liberal 2nd Member of Parliament, born in Groningen, Netherlands (d. 1916)
1863 Arthur Henderson, British Labour minister (Nobel Peace Prize 1934), born in Glasgow, Scotland (d. 1935)
1863 Willis Cuttell, English cricket spin bowler (2 Tests, 6 wickets; Lancashire CCC), born in Sheffield, England (d. 1929)
1866 Adolf Meyer, American psychiatrist and neurologist (pioneered mental hygiene), born in Niederweningen, Switzerland (d. 1950)
1871 Alma Kruger, American actress (Made For Each Other), born in Pittsburgh, Pennsylvania (d. 1960)
Austrian-American composer (Verklärte Nacht – Transfigured Night; 2nd Quartet), and painter associated with the expressionist movement, born in Vienna, Austria
1874 Henry F. Ashurst, American Democratic politician (U.S. Senator from Arizona), born in Winnemucca, Nevada (d. 1962)
1876 Sherwood Anderson, American author and publisher (Winesburg Ohio), born in Camden, Ohio (d. 1941)
1877 Stanley Lord, Captain of the SS Californian the night of the Titanic disaster, born in Bolton, Lancashire, England (d. 1962)
1877 Wilhelm Filchner, German explorer who led the German Antarctic expedition of 1911–12, born in Munich, Germany (d. 1957)
1880 Jesse L. Lasky, American film producer (The Dictator, The Squaw Man), born in San Francisco, California (d. 1958)
1882 Henri Potiron, French composer, born in Rezé-lès-Nantes, Loire-Atlantique, France (d. 1972)
1882 Ramón Grau, 6th and 10th President of Cuba, born in La Palma, Spanish Cuba (d. 1969)
1885 Wilhelm Blaschke, Austrian integral geometer, born in Graz, Austria (d. 1962)
1886 Alain LeRoy Locke, African-American writer and philosopher “Father of the Harlem Renaissance”, born in Philadelphia, Pennsylvania (d. 1954)
1886 Robert Robinson, British chemist (Nobel Prize in Chemistry, 1947 for investigation of plant lipids), born in Rufford, England (d. 1975) [1]
1887 Leopold Ružička, Croatian-Swiss chemist (Nobel 1939), born in Vukovar, Croatia (d. 1976)
1889 Pierre Reverdy, French poet (Nord-Sud), born in Occitanie (d. 1960)
1893 Larry Shields, American jazz clarinetist (Original Dixieland Jazz Band), born in New Orleans, Louisiana (d. 1953)
1894 J. B. Priestly, English novelist and scriptwriter (The Good Companions, An Inspector Calls), born in Bradford, United Kingdom (d. 1984)
1894 Julian Tuwim, Polish poet and lyricist, born in Łódź, Congress Poland (d. 1953)
1895 Ruth McDevitt, American actress (All in the Family), born in Coldwater, Michigan (d. 1976)
1896 Morris Kirksey, American athlete (Olympic gold 100m, 4 x 100m, men’s rugby 1920), born in Waxahachie, Texas (d. 1981)
1896 Tadeusz Szeligowski, Polish composer (The Peacock and the Girl), born in Lemberg, Austro-Hungarian Galicia (d. 1963)
1897 Gaspar Cassadó, Spanish cellist and composer, born in Barcelona, Spain (d. 1966)
1899 Anton Constandse, Dutch anarchist and writer, born in Brouwershaven, Netherlands (d. 1985)
1899 Corneliu Zelea Codreanu, Romanian politician (founder and leader of the Iron Guard), born in Huși, Vaslui County, Romania (d. 1938)
1899 Frank “Big Boy” Goudie, American jazz tenor saxophonist and clarinetist, and upholsterer, born in Youngsville, Louisiana (d. 1964)
1900 Gladys George, American actress (Roaring Twenties), born in Patten, Maine (d. 1954)
1902 Arthur Mitchell, English cricket batsman (6 Tests, 2 x 50; Yorkshire CCC), born in Baildon, England (d. 1976)
1902 Hermine Heijermans, Dutch actress, politician and author (Grote Klaas en kleine Klaas), born in Amsterdam, Netherlands (d. 1983)
1902 Leland Hayward, American producer (Mister Roberts, Spirit of St Louis), born in Nebraska City (d. 1971)
French-born American actress (It Happened One Night, Texas Lady), born in Paris
1907 Victor Reinganum, English artist and illustrator, born in London (d. 1995)
1908 (Leon) “Chu” Berry, American swing jazz tenor saxophonist (Fletcher Henderson; Cab Calloway), born in Wheeling, West Virginia (d. 1941)
1908 Ray Green, American composer and publisher, born in Cavendish, Missouri (d. 1997)
1909 Herbert Berghof, Austrian actor (Belarus File, Harry and Tonto, Target), born in Vienna, Austria-Hungary (d. 1990)
1909 Leith Stevens, American pianist, composer and conductor of scores for radio (Suspense), film (The Wild Ones; War of the Worlds), and television (Climax!), born in Mount Moriah, Missouri (d. 1970)
1911 Bill Monroe, American singer known as the “Father of Bluegrass” (“Blue Moon of Kentucky”), born in Rosine, Kentucky (d. 1996)
1912 Reta Shaw, American actress (Ghost & Mrs Muir, Mary Poppins, Picnic), born in South Paris, Maine (d. 1982)
1913 Roy Engle, American writer and actor (The Man from Planet X, The Wild Wild West, My Favorite Martian), born in St. Louis, Missouri (d. 1980)
1914 Leonard Feather, British jazz critic and musician, born in London (d. 1994)
1915 Clint Frank, American College Football Hall of Fame halfback (Heisman Trophy 1937; Yale), born in St. Louis, Missouri (d. 1992)
1915 Peter Wykeham, Royal Air Force fighter pilot, born in Kotra, Sandhurst, Berkshire (d. 1995)
1916 Richard “Dick” Haymes, Argentine-American actor and singer (State Fair; Real Life; Betrayal), born in Buenos Aires, Argentina (d. 1980)
British author (Charlie and the Chocolate Factory, The BFG), born in Cardiff, Wales
1917 Jón Thórarinsson, Icelandic composer and musicologist, born in Gilsárteigur, Iceland (d. 2012)
1917 Robert Ward, American composer (Pantaloon), born in Cleveland, Ohio (d. 2013)
1918 Ray Charles, American orchestra leader (Perry Como), born in Chicago, Illinois (d. 2015)
American sister of President John F. Kennedy who underwent a frontal lobotomy, born in Brookline, Massachusetts
1919 George Weidenfeld, British publisher (Weidenfeld & Nicolson), born in Vienna (d. 2016)
1919 Mary Midgley, British-American philosopher (Animals and Why They Matter), born in London (d. 2018)
1920 Carole Mathews [Jean Deifel], American actress (The Californians, Swamp Women), born in Montgomery, Illinois (d. 2014)
1922 Antonia Pantoja, Puerto Rican-American educator and civil rights activist, 1st Puerto Rican woman awarded Presidential Medal of Freedom, born in San Juan, Puerto Rico (d. 2002) [1]
1922 Charles Brown, American blues singer and pianist (“Merry Christmas, Baby”), born in Texas City (d. 1999)
1922 Yma Sumac [Chavarri], Peruvian-American 5 octave soprano (Omar Khayyam), born in Ichocan, Cajamarca, Peru (d. 2008)
1923 Édouard Boubat, French photographer, born in Montmartre, Paris (d. 1999)
1924 Harold Blair, Australian tenor and Aboriginal activist, born in Cherbourg Aboriginal Reserve, Queensland, Australia (d. 1976)
1924 Maurice Jarre, French Academy and Grammy Award-winning film composer (Lawrence Of Arabia; Doctor Zhivago; Witness; Fatal Attraction), born in Lyon, France (d. 2009)
1924 Norman Alden, American character actor (I Never Promised You a Rose Garden), born in Fort Worth, Texas (d. 2012)
1924 Scott Brady [Gerald Tierney], American actor (Shotgun Slade, China Syndrome, Gremlins, Johnny Guitar), born in Brooklyn, New York (d. 1985)
1925 Gabriel Charpentier, Canadian composer, and poet, born in Richmond, Quebec (d. 2019)
1925 Mel Tormé, American jazz singer, known as ‘The Velvet Fog’ and composer (The Christmas Song), born in Chicago, Illinois (d. 1999)
1926 Emile Francis, Canadian Hockey HOF coach (NY Rangers 1965-75; St. Louis Blues) and executive (GM: NY Rangers, St. Louis Blues, Hartford Whalers), born in North Battleford, Saskatchewan (d. 2022) [1]
1927 Samuel Smith, American chemist and co-inventor of Scotchgard, born in New York City (d. 2005) [1]
1928 Ernest L. Boyer, American educator and chancellor (NY’s State Universities-SUNY), born in Dayton, Ohio (d. 1995)
1929 Nicolai Ghiaurov, Bulgarian operatic basso singer, born in Velingrad, Bulgaria (d. 2004)
1930 Jimmy McLane, American swimmer (Olympic gold 1500m 1948), born in Pittsburgh, Pennsylvania (d. 2020)
1930 Robert Gavron, Baron Gavron, English publisher and multi-millionaire (St Ives Group), born in London (d. 2015)
1931 Adrienne Kennedy, American educator and playwright (Ohio State Murders, Funnyhouse of a Negro), born in Pittsburgh, Pennsylvania
1931 Barbara Bain, American actress (Cinnamon-Mission Impossible, Space 1999), born in Chicago, Illinois
1931 Marjorie Jackson, Australian sprinter (Olympic gold 1952) and 33rd Governor of South Australia, born in Coffs Harbour, Australia
1932 Bengt Hallberg, Swedish jazz pianist and composer, born in Gothenburg, Sweden (d. 2013)
1932 Bronius Kutavičius, Lithuanian composer (The Gates of Jerusalem; Lokys) and teacher (Čiurlionis School of Art, 1975-2000), born in Molainiai, Lithuania (d. 2021)
1933 Eileen Fulton [Margaret McLarty], American actress (As the World Turns, 1960-2010; Our Private World), mystery novelist, and cabaret singer, born in Asheville, North Carolina (d. 2025)
1934 Bill Woolsey, American swimmer (Olympic gold men’s 4×200m freestyle relay 1952, silver 1956), born in Honolulu, Hawaii (d. 2022)
1936 Stefano Delle Chiaie, Italian neo-fascist terrorist (founder of Avanguardia Nazionale), born in Caserta, Italy (d. 2019)
1937 Don Bluth, American animator and film director (The Secret of NIMH), born in El Paso, Texas
1937 Fred Silverman, American broadcasting executive and producer (ABC, NBC and CBS), born in New York City (d. 2020)
1938 Judith Martin, American author, journalist and columnist (Miss Manners), born in Washington, D.C.
1939 Bill Janklow, American politician and four-term Governor of South Dakota (Republican: 1979-87, 1995-2003), born in Chicago, Illinois (d. 2012)
1939 Elaine Delmar (neé Hutchinson), British jazz and cabaret singer and stage actress, born in Harpenden, Hertfordshire, England [some sources cite birthday as 9/01]
1939 Gene Page, American arranger and composer (Righteous Brothers; Marvin Gaye; Whitney Houston), born in Los Angeles, California (d. 1998)
1939 Larry Speakes, Acting White House Press Secretary under President Ronald Reagan, born in Cleveland, Mississippi (d. 2014)
1939 Richard Kiel, American actor (Jaws in “Moonraker”; Skidoo; So Fine), born in Detroit, Michigan, (d. 2014)
1940 (Lionel) “Linc” Chamberland, American R&B and jazz-fusion guitarist, born in Norwalk, Connecticut (d. 1987)
1940 Joyce Schouten, Dutch pop singer (Fouryo’s – “Dance With Me One More Time”), born in Amsterdam, Netherlands
1940 Óscar Arias Sánchez, 40th & 45th President of Costa Rica (Nobel Peace Prize 1987), born in Heredia, Costa Rica
1941 Ahmet Necdet Sezer, Turkish politician (10th President of Turkey), born in Afyonkarahisar, Turkey
1941 David Clayton-Thomas [Thomsett], Canadian singer (Blood, Sweat & Tears – “Spinning Wheel”), born in Kingston upon Thames, Surrey, England
1941 Jan-Åke Edvinsson, Swedish ice hockey administrator (International Ice Hockey Federation IIHF general secretary 1986-2006), born in Trolle Ljungby, Sweden (d. 2022)
1941 Tadao Ando, Japanese self-taught architect (Church of the Light), born in Osaka, Japan
1942 Béla Károlyi, Hungarian Romanian-American gymnastics coach (Nadia Comăneci, Mary Lou Retton, Kerri Strug), born in Kolozsvár, Hungary (d. 2024) [1]
1942 Vladislav Zolotaryov, Soviet Russian bayanist (button accordion player), and composer (Six Children’s Suites), born in De-kastri, Khabarovsk Krai, USSR (d. 1975)
1944 Carol Barnes, British television news journalist (ITN; ITV), born in Norwich, England (d. 2008)
1944 Jacqueline Bisset, English actress (Class, Deep, Secrets), born in Weybridge, Surrey, England
1944 Les Harvey, Scottish rock guitarist (Stone The Crows), born in Glasgow, Scotland (d. 1972)
1944 Peter Cetera, American rock bassist, lead singer, and songwriter (Chicago, 1967-85 – “25 or 6 to 4″ ;”If You Leave Me Now”), born in Chicago, Illinois
1945 Alain Louvier, French contemporary classical composer, born in Paris, France
1945 Andres Küng, Swedish-Estonian politician and journalist, born in Ockelbo, Gävleborg County, Sweden (d. 2002)
1945 Noël Godin, Belgian writer and humorist known for throwing a pie at Bill Gates, born in Liège, Belgium
1945 Rick Wise, American MLB pitcher, 1964-82, 2X All-Star (Philadelphia Phillies, St. Louis Cardinals, and 3 other teams), born in Jackson, Michigan
1947 Juan Sol, Spanish soccer defender (28 caps; Valencia, Real Madrid), born in Elgoibar, Spain (d. 2020)
1948 Clyde Kusatsu, American actor (Ali-Bring ’em Back Alive), born in Honolulu, Hawaii
1948 Dimitri Nanopoulos, Greek physicist, born in Athens, Greece
1948 Nell Carter, American actress (Gimme A Break; Lobo), born in Birmingham, Alabama (d. 2003)
1948 Fijian military officer who led the 1987 coup and Prime Minister of Fiji (1992-97, 2022-), born in Cakaudrove, Fiji
1949 Craig McGregor, American rock bassist (Foghat, 1976-2018), born in Sioux City, Iowa (d. 2018)
1950 Jeff Lowe, American mountain climber (co-founder Lowe Alpine), born in Ogden, Utah (d. 2018)
1950 Włodzimierz Cimoszewicz, Polish politician (8th Prime Minister of Poland), born in Warsaw, Poland
1951 Jean Smart, American actress (Designing Women, Hacks), born in Seattle, Washington
1952 Don Was [Fagenson], American singer, bass player (Was (Not Was) – “Walk The Dinosaur”), record producer (Bonnie Raitt; B-52s; Bob Dylan; Ringo Starr; Rolling Stones), record label executive (Blue Note); and documentary film maker (I Just Wasn’t Made for These Times), born in Detroit, Michigan
1952 Johanna Klier-Schaller, German 100m hurdler (Olympic gold 1976), born in Artern, Bezirk Halle, Germany
1952 Karen Wyman, American singer (Long & Winding Road), born in The Bronx, New York City
1952 Randy Jones, American musician (The Village People (Cowboy) -“Y.M.C.A.”), born in Raleigh, North Carolina
1952 Ray Sibille, American jockey (Breeder’s Cup Turf 1988), born in Sunset, Louisiana
1952 Raymond O’Connor, American actor (The Rock), born in South Bronx, New York
1953 Taryn Power, American actress (Maria); youngest daughter of Tyrone Power Mexican actress Linda Christian, born in Los Angeles, California (d. 2020)
1954 Denis “Den” Hegarty, Irish doo-wop singer (The Darts – “The Boy From New York City”), born in Dublin, Ireland
1954 Steve Kilbey, English-Australian singer-songwriter and bass player (The Church), born in Welwyn Garden City, England
1954 Teddy Mueller, American rock drummer (Axe), born in Milwaukee, Wisconsin (d. 2012)
1955 Joe Morris, American jazz, avant-garde, and improvisational guitarist, banjolele player (“Today On Earth”), and educator (New England Conservatory), born in New Haven, Connecticut
1956 (Joan) “Joni” Sledge, American vocalist (Sister Sledge “We Are Family”), born in Philadelphia, Pennsylvania (d. 2017)
1956 Alain Ducasse, French-born Monégasque chef, born in Orthez, France
1956 David Mansfield, American session and touring fiddler, guitarist, mandolin player (Bob Dylan; The Alpha Band; Buce Hornsby and The Range), and film score composer, born in Leonia, New Jersey
1956 Oribe Canales, Cuban American celebrity hairdresser, born in Havana, Cuba (d. 2018)
1957 Bongbong Marcos [Ferdinand Marcos Jr], Philippine politician (President of the Philippines 2022-), born in Santa Mesa, Manila
1957 John G. Trueschler, American politician (member of the Maryland House of Delegates), born in Baltimore, Maryland
1957 Mark Wiebe, American golfer (British Senior Open 2013), born in Seaside, Oregon
1957 Vinny Appice, American rock drummer (Black Sabbath), born in Brooklyn, New York City
1958 Ann Dusenberry, American actress (Jaws 2, Lies, Basic Training), born in Tucson, Arizona
1958 Mark Brokaw, American theatre director (This is Our Youth, How I Learned to Drive), born in Aledo, Illinois (d. 2025)
1959 Ralph Northam, American politician, Governor of Virginia (2018-), born in Nassawadox, Virginia
1959 Sheldon Reynolds, American soul and funk guitarist (Commodores, 1983-87; Earth, Wind & Fire, 1987-2002), born in Cincinnati, Ohio (d. 2023)
1960 Greg Baldwin, American voiceover actor (Avatar: The Last Airbender), born in Grants, New Mexico
1961 Dave Mustaine, American heavy metal guitarist and singer (Metallica, 1981-83; Megadeth), born in La Mesa, California
1961 KK Null [Kazuyuki Kishino], Japanese musician, born in Tokyo, Japan
1961 Peter Roskam, American politician (Member of the U.S. House of Representatives from Illinois), born in Hinsdale, Illinois
1962 Neal Lancaster, American golfer (US Open 1995 4th), born in Smithfield, North Carolina
1962 Tõnu Õnnepalu, Estonian poet and author, born in Tallinn, Estonia
1963 Theodoros Roussopoulos, Greek politician (Minister of State), born in Messinia, Greece
1964 Simegnew Bekele, Ethiopian dam engineer (Grand Ethiopian Renaissance Dam), born in Maksegnit, Ethiopia (d. 2018)
1965 Annie Duke, American poker player, born in Concord, New Hampshire
1965 Jeffrey Ross, American stand-up comedian (Comedy Central Roasts, Take a Banana For the Ride), born in Springfield, New Jersey
1965 Zak Starkey, English rock drummer (Oasis; The Who), son of Beatle Ringo Starr, born in Hammersmith, London
1966 Igor Kravchuk, Russian NHL defenseman (Team Russia, St Louis), born in Ufa, Russia
1966 Louis Mandylor, Australian actor (My Big Fat Greek Wedding), born in Melbourne, Australia
1966 Maria Furtwängler, German physician and actress (Tatort, Shades of Happiness), born in Munich, Germany
1967 Michael Johnson, American 200m/400m runner (Olympic-2 gold-96), born in Dallas, Texas
1967 Stephen Perkins, American drummer and percussionist (Jane’s Addiction; Porno for Pyros), born in Los Angeles, California
1967 Tim ‘Ripper’ Owens, American singer (Iced Earth; Judas Priest), born in Akron, Ohio
1968 Bernie Williams, Puerto Rican baseball outfielder (World Series 1996, 98–2000; ALCS MVP 1996; 5 × MLB All-Star; NY Yankees), born in San Juan, Puerto Rico
1968 Brad Johnson, American NFL quarterback (Minnesota Vikings), born in Marietta, Georgia
1968 Denny Neagle, American baseball pitcher (MLB All Star 1995, 97; NL wins leader 1997; Pittsburgh Pirates, Atlanta Braves), born in Gambrills, Maryland
1968 Emma Wiklund [Sjöberg], Swedish businesswoman and supermodel (Chanel, Versace), born in Stockholm, Sweden
1968 John Roderick, American indie-rock musician, singer-songwriter (The Long Winters),and podcaster (Omnibus; Friendly Fire), born in Seattle, Washington
1969 Bong Joon-ho, South Korean film director (Parasite), born in Daegu, South Korea
1782 The Grand Assault on Gibraltar by the allied French and Spanish fleets, including ten floating batteries and land forces, is heavily defeated by the British garrison, with all floating batteries destroyed and allied casualties of 1,473 compared to only 83 for the British
Straw Hat Riot begins in New York City as youths aggressively taunt men wearing straw hats, getting an early jump on the unofficial season’s end date of September 15; confrontations continue longer than usual, lasting eight days
For the first time, astronomers have seen the inner layers of a star revealed in its final moments. The finding suggests a new, more violent pathway for how massive stars die. Credit: Shutterstock
A distant supernova exposed elements from a star’s core. The result reshapes ideas of how massive stars evolve.
According to long-standing theory, stars are built in layers like onions, with each layer composed of different elements that grow heavier toward the core. While this model is widely accepted, directly observing a star’s deeper layers has been nearly impossible.
Until now.
Astronomers using the Keck Observatory in Hawaii have collected spectroscopic data from a supernova first identified by the Zwicky Transient Facility in 2021. The event, designated SN 2021yf, occurred 2.2 billion light-years away. The Keck observations revealed ionized silicon, sulfur, and argon, elements never before detected in a supernova because they are normally hidden beneath outer layers.
This figure shows the elements detected in the spectrum from SN 2021yf with the Keck’s Low Resolution Imaging Spectrometer one day after the ZTF spotted it. “The spectrum reveals narrow emission lines of highly ionized species of silicon, sulfur, and argon, which have never been seen in any SN before, as well as doubly ionized carbon, singly ionized magnesium, and neutral helium,” the authors write. The observations also show that some of these elements are moving at about 3,000 km/sec in an ejected circumstellar medium. Credit: Schulze et al. 2025
Confirming and challenging theory
The finding supports some theoretical predictions about the structure of exploding stars but also raises new challenges.
It is well established that massive stars shed material from their outer layers as they near the point of collapse into a supernova. This process has been documented many times, and the new data confirm it again. However, SN 2021yf appears to have lost far more material than any star observed before, leaving astronomers to reconsider how extreme this stripping process can be.
The observations are presented in a new paper titled “A cosmic formation site of silicon and sulfur revealed by a new type of supernova explosion.” The lead author is Steve Schulze, a research associate at Northwestern University’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA).
“This is the first time we have seen a star that was essentially stripped to the bone,” said lead author Schulze. “It shows us how stars are structured and proves that stars can lose a lot of material before they explode. Not only can they lose their outermost layers, but they can be completely stripped all the way down to the core and still produce a brilliant explosion that we can observe from very, very far distances.”
Artist’s illustration of the supernova’s aftermath. Even after the star was stripped down to its core, it continued to experience violent mass-loss episodes, ejecting shells of material rich in silicon (grey), sulfur (yellow), and argon (purple). The catastrophic collision of these massive shells, as depicted in this illustration, generated a brilliant supernova explosion visible across 2.2 billion light-years of space. Credit: Keck Observatory/Adam Makarenko
When astronomers study supernovae, the most prominent signals usually come from light elements such as hydrogen and helium. If these outer layers have already been stripped away, signatures of carbon, oxygen, neon, and magnesium may also become visible. The deeper shells, which contain heavier elements like silicon, sulfur, and argon, generally remain hidden from view.
For decades, stellar theory has described massive stars as being structured in concentric layers, much like the rings of an onion. The new Keck data provide striking confirmation of this model. By revealing the star’s inner composition just before its explosion, these observations offer the clearest evidence yet in direct support of the layered structure predicted by theory.
When astronomers spotted this supernova, its lighter outer layers were stripped away. For the first time, they saw a supernova’s inner layers made of heavier elements usually hidden from view. Credit: W.M. Keck Observatory/Adam Makarenko
Unexpected mass loss
However, the observations also pose a challenge. Astrophysicists know that massive stars eject material before exploding as supernova. Shock waves from the expelled matter interact with the surrounding medium, heating it and creating observable light signatures. But SN 2021yf must have ejected much more material than thought possible, because it’s stripped down to its core.
“This event quite literally looks like nothing anyone has ever seen before,” added Adam Miller, an assistant professor of physics and astronomy at Northwestern and senior author on the study. “This star is telling us that our ideas and theories for how stars evolve are too narrow. It’s not that our textbooks are incorrect, but they clearly do not fully capture everything produced in nature. There must be more exotic pathways for a massive star to end its life that we hadn’t considered.”
This table shows supernova taxonomy. SN 2021yf could be a new type called Type Ien. The ‘e’ signifies the position of the silicon/sulfur layer in the star’s structure, and the “n” signifies that the emission lines are narrow. Credit: Wikipedia
Massive stars have the power to fuse lighter elements into heavier elements in a process called nucleosynthesis. (Without stellar nucleosynthesis, the only elements in the Universe would be those created during the Big Bang.) Throughout its life of fusion, a massive star burns lighter elements like hydrogen and helium in its outer shells, while in its core it burns successively heavier elements in its deeper layers. Eventually, a star ends up with an iron core. Iron can’t be burned to release more energy, so once the core is dominated by iron, fusion virtually ceases. Without the outward pressure from fusion, the star collapses in on itself and explodes as a supernova.
Seeing the hidden layers
Astrophysicists have observed layers of helium, carbon, and oxygen in exploding stars before, which are visible after the star has ejected its outer layer of hydrogen. By observing the silicon, sulfur, and argon, it means that this star has ejected not only its outer helium layer, but other layers as well. This likely happened in multiple episodes rather than all at once.
“Stars experience very strong instabilities,” Schulze said. “These instabilities are so violent that they can cause the star to contract. Then, it suddenly liberates so much energy that it sheds its outermost layers. It can do this multiple times.”
Alex Filippenko is a professor of astronomy at UC Berkeley and a co-author of the paper. He happened to be working with the Keck when SN 2021yf was discovered, and quickly pivoted to capture its spectrum withe the Keck’s LRIS. “It’s so exciting to discover a new class of exploding star, especially one that provides a confirmation of some of our theories of how massive stars evolve with time yet also reveals interesting new puzzles,” said Filippenko. “It was very fortunate that my team was using the Keck I telescope the night SN 2021yfj was discovered — we were able to obtain a spectrum that directly led to the realization that this was an incredibly special new type of supernova. Opportunities of this kind are rare!”
Toward a new supernova type
The silicon, sulfur, and argon in the star weren’t always present. These elements were created via nucleosynthesis in the star’s interior as it approached the end of its life.
“This star lost most of the material that it produced throughout its lifetime,” Schulze said. “So, we could only see the material formed during the months right before its explosion. Something very violent must have happened to cause that.”
That question is at the heart of this discovery. Is SN 2021yfj a new type of supernova defined by a powerful new process that stripped it of its outer layers? Some of the explanations the team is considering are interactions with a companion star, unusual and extremely powerful stellar winds, and a massive eruption that preceded the supernova explosion.
Rethinking stellar explosions
“Massive stars can lose a substantial amount of their birth mass through stellar winds, eruptions, and interaction with a companion star,” the researchers write in their paper. The presence of helium in this star’s circumstellar material is puzzling, since helium is usually ejected earlier in the SN process. “Since massive stars tend to live in binary systems, it may not be too unlikely to have a helium-star companion with a strong wind,” they write. This could explain the helium.
The researchers think that the most likely explanation is that this massive star simply tore itself apart. Stellar cores of massive stars are under intense gravitational pressure that raises their core temperatures until nuclear fusion is reignited, generating a powerful explosion. The explosion blasts away the star’s outer layers. The process is repetitive, and each time it happens, more material is ejected until the deeper core is visible.
Supernovae are classified according to spectroscopy, and classifications are centered on hydrogen. Type 1 show helium but no hydrogen and Type 2 show hydrogen. Then there are sub-types under each of those classifications based on other spectral lines. The sequence of labelled sub-types reflects the amount of stripping in the progenitor stars.
First of its kind
“Our observations … suggest that SN 2021yfj is indeed the first example of a Type Ien SN,” the researchers write in their paper. This is a new type that lacks lines from hydrogen or helium, and is instead dominated by emission lines from highly ionized silicon, sulfur, and argon.
Since there’s only one example of this type, there are still many questions. As is often the case in astronomy, a larger dataset will likely lead to some answers.
“While we have a theory for how nature created this particular explosion,” Miller said, “I wouldn’t bet my life that it’s correct, because we still only have one discovered example. We still don’t fully understand how nature created this particular explosion. This star underscores the need to uncover more of these rare supernovae, so we can continue to study them.”
Reference: “A cosmic formation site of silicon and sulphur revealed by a new type of supernova explosion” by Steve Schulze, Avishay Gal-Yam, Luc Dessart, Adam A. Miller, Stan E. Woosley, Yi Yang, Mattia Bulla, Ofer Yaron, Jesper Sollerman, Alexei V. Filippenko, K-Ryan Hinds, Daniel A. Perley, Daichi Tsuna, Ragnhild Lunnan, Nikhil Sarin, Sean J. Brennan, Thomas G. Brink, Rachel J. Bruch, Ping Chen, Kaustav K. Das, Suhail Dhawan, Claes Fransson, Christoffer Fremling, Anjasha Gangopadhyay, Ido Irani, Anders Jerkstrand, Nikola Knezevic, Doron Kushnir, Keiichi Maeda, Kate Maguire, Eran Ofek, Conor M. B. Omand, Yu-Jing Qin, Yashvi Sharma, Tawny Sit, Gokul P. Srinivasaragavan, Nora L. Strothjohann, Yuki Takei, Eli Waxman, Lin Yan, Yuhan Yao, WeiKang Zheng, Erez A. Zimmerman, Eric C. Bellm, Michael W. Coughlin, Frank. J. Masci, Josiah Purdum, Mickael Rigault, Avery Wold and Shrinivas R. Kulkarni, 3 September 2024, arXiv. DOI: 10.48550/arXiv.2409.02054
Adapted from an article originally published on Universe Today.
Conny Waters – AncientPages.com – Recent research provides compelling evidence that many individuals buried in Seddin, Germany, during the Bronze Age were not native to the region but originated from elsewhere.
Although archaeologists had already discovered artefacts from various parts of Europe around Seddin, this groundbreaking study now confirms that people themselves travelled and established roots in Seddin. This marks the first bioarchaeological investigation of human skeletal remains from the area.
Thus, researchers have obtained significant insight into ancient migration patterns of people who travelled around Europe during the Bronze Age, a period from approximately 1550 to 1200 BCE.
The individuals studied primarily showed a non-local origin and represented the elite class, rather than the region’s broader population. Their burial mounds containing graves with swords as well as impressive bronze and clay grave goods,were both rich and monumental.
The team found that the abundance of well-preserved archaeological finds dating to the Nordic Late Bronze Age (ca. 11th-8th century BCE) suggests that by that time, the site had developed into an important political and cultural area.
The most interesting and deserving attention monument, located in the area is the Königsgrab, or King’s Grave, of Seddin. This 9th-century BCE site features a monumental burial mound with a polygonal stone chamber tomb containing bronze grave goods.
About one kikometer north of the Königsgrab is another burial mound, Wickbold I. Like the Königsgrab, Wickbold I was built in the 9th century BCE and contains rich bronze grave goods. However, little has been published on Wickbold I.
Grave goods from these sites indicate connections with foreign traditions, suggesting Seddin’s integration into Nordic Bronze Age culture.
Overview for the burial mounds Königsgrab and Wickbold I. Image source
For instance, a knife from Wickbold I resembles Danish grave goods, and its socketed bronze axes are similar to minor axes found in Sweden, Denmark, northern Germany, and the Netherlands. Meanwhile, the phalera covering the Königsgrab urn is unique to southern Europe’s urnfield culture.
During the Late Bronze Age, spanning roughly from the 13th to the 12th centuries BCE, European communities developed extensive trade and exchange contacts that linked various cultures through networks. The area around Seddin in north-western Brandenburg, Germany, was a central hub within one of these networks. Both international connections and exchanges among different cultures during the period between 900 and 700 BCE flourished, but these activities demanded extensive human mobility.
”The strontium signatures of most of the buried individuals point both to south Scandinavia as well as Central Europe, and possible northern Italy,” said professor Kristian Kristiansen, University of Gothenburg.
“This is in good accordance with the archaeological knowledge that shows intensified trade between these regions.”.
Flatheads grow fast in this river system, attain large body sizes, and can eat a variety of prey. Because adult flatheads have few natural predators, they can exert strong control over the ecosystem. Credit: Penn State
Flathead catfish, once native to the Mississippi River basin, have stealthily risen to the top of Pennsylvania’s Susquehanna River.
Growing fast, eating almost anything, and facing no real predators, they now dominate the food web. Researchers discovered that native fish like bass and channel catfish are shifting diets and behaviors just to survive, revealing how one invasive species can upend entire ecosystems.
Invasive Flathead Catfish on the Rise
Flathead catfish are powerful opportunistic predators originally from the Mississippi River basin. When introduced into new waterways or spreading from nearby river systems, they can severely damage native fish populations and recreational fisheries, disrupting entire ecosystems. Concern over these impacts prompted scientists from Penn State, the U.S. Geological Survey (USGS), and the Pennsylvania Fish and Boat Commission to investigate how flathead catfish are altering the food web and energy flow in Pennsylvania’s Susquehanna River. The species was first detected there in 1991, and its numbers have increased dramatically since then.
“Flatheads grow fast in this river system, attain large body sizes, and can eat a variety of prey,” explained study first author Olivia Hodgson, a master’s student in Penn State’s Intercollege Graduate Degree Program in Ecology. “Because adult flatheads have few natural predators, flathead catfish can exert strong control over the ecosystem.”
Hodgson worked with Tyler Wagner, a USGS scientist with the Pennsylvania Cooperative Fish and Wildlife Research Unit Program and an affiliate professor of fisheries ecology at Penn State. Wagner is the senior author of the study. Their findings, published September 4 in Ecology, confirmed that flathead catfish have become apex predators in the river.
Study coauthor Geoffrey Smith, Susquehanna River biologist for the Pennsylvania Fish and Boat Commission, with a big flathead catfish. Credit: Penn State
Outcompeting Native Predators
The researchers found that flatheads hold the highest trophic position (the place an organism occupies in a food web based on what it eats and what eats it). Their position ranked above long-standing top predators like smallmouth bass and channel catfish. In areas where flatheads are present, channel catfish dropped to lower levels of the food chain, likely either because they are being displaced by the newcomers or deliberately avoiding them. In those same sections of the river, all species examined showed wider, overlapping diets.
“This suggests that resident species are changing what they eat to avoid competing with or being eaten by the invader,” Hodgson said. “These findings support the ‘trophic disruption hypothesis,’ that says when a new predator enters an ecosystem, it forces existing species to alter their behavior, diets, and roles in the food web. This can destabilize ecosystems over time. Our study highlights how an invasive species can do more than just reduce native populations — it can reshape entire food webs and change how energy moves through ecosystems.”
Studying Food Web Disruption
Although the predatory effects of invasive catfishes on native fish communities have been documented — such as in a recent study on the Susquehanna River led by researchers at Penn State — the impacts of invasion on riverine food webs are poorly understood, Hodgson noted. This study quantified the effects of invasive flathead catfish on the food web in the Susquehanna by comparing uninvaded river sections to invaded sections, focusing on several key species: flathead catfish — invader, channel catfish and smallmouth bass — resident predators, and crayfish and minnows — prey.
In addition to evaluating trophic position, the researchers analyzed the isotopic niche occupied by the fish species — the range of carbon and nitrogen markers found within the tissues of an organism, reflecting its diet and habitat, providing insights into its ecological role.
Study coauthor Sydney Stark, who recently graduated from Penn State with a master’s degree in wildlife and fisheries science, lifts a 40-pound flathead catfish. Credit: Penn State
To reach their conclusions, the researchers employed stable isotope analysis, a widely used tool that can explain patterns within a food web, highlighting links between trophic positions, as well as the breadth and overlap of trophic niches. Stable isotope analysis is especially useful for studying invasion ecology, such as investigating trophic reorganization and trophic overlap between introduced and resident species.
When fish eat, their bodies incorporate the isotopic signature of their food. By sampling their tissues, scientists can measure nitrogen isotopes and determine their diet, carbon isotopes to determine habitat use, and compare isotopic signatures across regions to deduce fish migration or habitat shifts. For this study, channel catfish, smallmouth bass, minnows, and crayfish were selected as focal species because a previous diet analysis conducted in collaboration with Penn State, USGS, and Pennsylvania Fish and Boat Commission researchers within the Susquehanna River showed that these species are important prey for flathead catfish.
Collecting and Processing Samples
The researchers collected a total of 279 fish and 64 crayfish for stable isotope analysis, including 79 flathead catfish, 45 smallmouth bass, 113 channel catfish, and 42 minnows comprising nine species. All samples were oven dried and ground to a fine powder using a mortar and pestle. Stable isotope samples were sent to Penn State’s Core Facilities and the Michigan State University Stable Isotope Laboratories for isotope determination.
“Stable isotope analysis explained patterns within the Susquehanna food web in habitats invaded and not invaded by the flathead catfish, and it allowed us to understand links between different species in the river food web and how invasive species might lead to changes in how native species interact and compete, what they eat and how their diets overlap, and if they might be displaced from preferred habitats by the invader,” Hodgson said. “We were able to infer resource use, helping us to better understand potential competition for resources and how this changes when flathead catfish become established.”
Reference: “Invasive predatory fish occupies highest trophic position leading to expansion of isotopic niches in a riverine food web” by Olivia C. Hodgson, Sydney Stark, Megan K. Schall, Geoffrey D. Smith, Kelly L. Smalling and Tyler Wagner, 4 September 2025, Ecology. DOI: 10.1002/ecy.70180
Contributing to the research were: Sydney Stark, recent Penn State graduate with a master’s degree in wildlife and fisheries science; Megan Schall, associate professor of biology and science at Penn State Hazleton; Geoffrey Smith, Susquehanna River biologist for the Pennsylvania Fish and Boat Commission; and Kelly Smalling, research hydrologist with the U.S. Geological Survey, New Jersey Water Science Center.
Funding for this research was provided by Pennsylvania Sea Grant and the U.S. Geological Survey.
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Contains information related to marketing campaigns of the user. These are shared with Google AdWords / Google Ads when the Google Ads and Google Analytics accounts are linked together.
90 days
__utma
ID used to identify users and sessions
2 years after last activity
__utmt
Used to monitor number of Google Analytics server requests
10 minutes
__utmb
Used to distinguish new sessions and visits. This cookie is set when the GA.js javascript library is loaded and there is no existing __utmb cookie. The cookie is updated every time data is sent to the Google Analytics server.
30 minutes after last activity
__utmc
Used only with old Urchin versions of Google Analytics and not with GA.js. Was used to distinguish between new sessions and visits at the end of a session.
End of session (browser)
__utmz
Contains information about the traffic source or campaign that directed user to the website. The cookie is set when the GA.js javascript is loaded and updated when data is sent to the Google Anaytics server
