SPACE/COSMOS
JWST measures the rate of the universe expansion
October 5, 2024
Evrim Yazgin
Cosmos science journalist
NASA’s James Webb Space Telescope has discovered a unique supernova which has helped measure the Hubble constant – the rate at which the universe is expanding.
Several research papers have been published from the observations of the supernova, dubbed Supernova H0pe. These papers can be accessed from this NASA blog post announcing the discovery
October 5, 2024
Evrim Yazgin
Cosmos science journalist
NASA’s James Webb Space Telescope has discovered a unique supernova which has helped measure the Hubble constant – the rate at which the universe is expanding.
Several research papers have been published from the observations of the supernova, dubbed Supernova H0pe. These papers can be accessed from this NASA blog post announcing the discovery
.
NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) image of the galaxy cluster with zoomed view of SN H0pe. Credit: NASA, ESA, CSA, STScI, B. Frye, R. Windhorst, S. Cohen, J. D’Silva, A. Koekemoer, J. Summers.
Supernovae are the bright, powerful explosions caused by the violent death of a massive star.
“It all started with one question by the team: ‘What are those 3 dots that weren’t there before? Could that be a supernova?’” says University of Arizona astronomer Brenda Frye.
The points of light were not visible when the Hubble telescope imaged the same cluster in 2015.
“Initial analyses confirmed that these dots corresponded to an exploding star, one with rare qualities,” Frye adds. “First, it’s a Type Ia supernova, an explosion of a white dwarf star. This type of supernova is generally called a ‘standard candle,’ meaning that the supernova had a known intrinsic brightness. Second, it is gravitationally lensed.”
Gravitational lensing is a consequence of the characteristics of the universe described by Einstein’s general theory of relativity. Massive objects – like galaxies – warp space-time around them, bending the trajectory of light.
When objects line up, this creates a lensing effect which can magnify more distant objects.
In this case, the lens consists of 3 galaxies sitting between us and the supernova, bending the supernova’s light into 3 images.
“This is similar to how a trifold vanity mirror presents 3 different images of a person sitting in front of it,” Frye explains. “Since each path had a different length, and light travelled at the same speed, the supernova was imaged in this Webb observation at 3 different times during its explosion.”
“Trifold supernova images are special: The time delays, supernova distance, and gravitational lensing properties yield a value for the Hubble constant. The supernova was named SN H0pe since it gives astronomers hope to better understand the universe’s changing expansion rate.
SN H0pe is tethered to a galaxy which existed about 3.5 billion years after the Big Bang. It is the most distant Type Ia supernovae observed.
Researchers around the world made independent observations of SN H0pe using models of how the galaxies might have lensed the light from the supernovae.
“Since the Type Ia supernova is a standard candle, each lens model was ‘graded’ by its ability to predict the time delays and supernova brightnesses relative to the true measured values,” Frye says.
“The team reports the value for the Hubble constant as 75.4 kilometres per second per megaparsec, plus 8.1 or minus 5.5. [One parsec is equivalent to 3.26 light-years of distance.] This is only the second measurement of the Hubble constant by this method, and the first time using a standard candle,” Frye adds.
“This is one of the great Webb discoveries, and is leading to a better understanding of this fundamental parameter of our universe.”
“Our team’s results are impactful: The Hubble constant value matches other measurements in the local universe, and is somewhat in tension with values obtained when the universe was young,” she adds.
Supernovae are the bright, powerful explosions caused by the violent death of a massive star.
“It all started with one question by the team: ‘What are those 3 dots that weren’t there before? Could that be a supernova?’” says University of Arizona astronomer Brenda Frye.
The points of light were not visible when the Hubble telescope imaged the same cluster in 2015.
“Initial analyses confirmed that these dots corresponded to an exploding star, one with rare qualities,” Frye adds. “First, it’s a Type Ia supernova, an explosion of a white dwarf star. This type of supernova is generally called a ‘standard candle,’ meaning that the supernova had a known intrinsic brightness. Second, it is gravitationally lensed.”
Gravitational lensing is a consequence of the characteristics of the universe described by Einstein’s general theory of relativity. Massive objects – like galaxies – warp space-time around them, bending the trajectory of light.
When objects line up, this creates a lensing effect which can magnify more distant objects.
In this case, the lens consists of 3 galaxies sitting between us and the supernova, bending the supernova’s light into 3 images.
“This is similar to how a trifold vanity mirror presents 3 different images of a person sitting in front of it,” Frye explains. “Since each path had a different length, and light travelled at the same speed, the supernova was imaged in this Webb observation at 3 different times during its explosion.”
“Trifold supernova images are special: The time delays, supernova distance, and gravitational lensing properties yield a value for the Hubble constant. The supernova was named SN H0pe since it gives astronomers hope to better understand the universe’s changing expansion rate.
SN H0pe is tethered to a galaxy which existed about 3.5 billion years after the Big Bang. It is the most distant Type Ia supernovae observed.
Researchers around the world made independent observations of SN H0pe using models of how the galaxies might have lensed the light from the supernovae.
“Since the Type Ia supernova is a standard candle, each lens model was ‘graded’ by its ability to predict the time delays and supernova brightnesses relative to the true measured values,” Frye says.
“The team reports the value for the Hubble constant as 75.4 kilometres per second per megaparsec, plus 8.1 or minus 5.5. [One parsec is equivalent to 3.26 light-years of distance.] This is only the second measurement of the Hubble constant by this method, and the first time using a standard candle,” Frye adds.
“This is one of the great Webb discoveries, and is leading to a better understanding of this fundamental parameter of our universe.”
“Our team’s results are impactful: The Hubble constant value matches other measurements in the local universe, and is somewhat in tension with values obtained when the universe was young,” she adds.
3-member Shenzhou-18 crew, currently aboard China’s Tiangong space station, to return in late October after 6-month mission
Serdar Dincel |05.10.2024 - TRT/AA
ISTANBUL
Space missions in China are gathering steam with a new manned mission set for later this month when the three-member crew of Shenzhou-18 returns home.
China Manned Space Agency (CMSA) released the exterior design of its red-and-white suit space suit last weekend, during a ceremony in southwestern Chongqing.
CMSA said the new Shenzhou-19 crew members will take control of space operations from the Shenzhou-18 taikonauts who are preparing to return home after conducting six months of research in space.
Ye Guangfu, teammates Li Cong and Li Guangsu of the Shenzhou-18 crew are currently aboard China's indigenously built Tiangong space station.
Ye is a fighter pilot and veteran astronaut who took part in the Shenzhou-13 mission in 2021.
The trio launched on April 25.
Shenzhou-18 is the 32nd mission of China's manned space program and the third manned mission during the operation and development stage of China's space station.
The Shenzhou 19 flight will mark China’s 14th crewed spaceflight and the 19th of the Shenzhou program.
The new crew that is set to be launched from the Jiuquan Satellite Launch Center in Inner Mongolia is composed of three People's Liberation Army Astronaut Corps, locally known as taikonauts, on the eighth flight to the Tianhe core module.
Tianhe core is the first module of the Tiangong space station.
China unveiled the name of its new spacecraft in February that will take astronauts on a lunar mission expected by the end of the decade.
The Mengzhou spacecraft and Lan Yue lunar lander will be China’s moon mission.
The white moon-landing spacesuit, expected to be ready before 2030, was showcased at the third Spacesuit Technology Forum held Sept. 28 by the China Astronaut Research and Training Center in Chongqing.
The red stripes on the upper limbs are inspired by the ribbons of the renowned flying apsaras from Dunhuang art, while the stripes on the lower limbs resemble the flames of a rocket launch.
It is designed to protect against the harsh thermal environment and lunar dust while the suit’s helmet features a panoramic, anti-glare visor, in addition to a separate long and short focal length camera.
The suit has a multi-functional integrated control console on the chest.
Chinese state media said the suit draws inspiration from traditional Chinese armor embodying "resilience, strength, and dignity, reflecting the courage and pioneering spirit of the Chinese people."
Adding more feathers to its cap, China's Chang'e-6 mission successfully returned in June, bringing 1,935.3 grams of soil and rocks, the first-ever from the far side of the moon.
In recent weeks, however, there have been a few rocket launch failures.
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