vendredi 20 mai 2022

NASA's Lucy Mission Observes a Lunar Eclipse

 






NASA - LUCY Mission patch.


May 20, 2022

NASA's Lucy spacecraft observed the May 15-16, 2022, total lunar eclipse from a unique vantage point, 64 million miles (100 million km) from the Earth, nearly 70% of the distance between the Earth and the Sun. Using its high-resolution panchromatic camera, L'LORRI, Lucy was able to watch as the Earth cast its shadow on the Moon. At this distance, the Earth and Moon appeared only 0.2 degrees apart to Lucy, having the same separation as a car’s tail-lights as viewed from a quarter-mile (400 m) away.

Video Credits: NASA/Goddard/APL/SwRI

In this timelapse video, the Earth is seen in the left (its rotation clearly visible) while the Moon (on the right, brightened sixfold to increase its visibility) disappears from view as it passes into the Earth’s shadow.  The video covers a period of almost three hours, from 9:40 p.m. EDT on May 15 to 12:30 a.m. EDT on May 16. The observations ended before the Moon emerged from the shadow.

NASA's Lucy spacecraft. Image Credit: NASA

The Lucy spacecraft launched in October 2021. It is currently traveling back towards Earth for a gravity assist on October 16, 2022, to help propel it on its journey to the Trojan asteroids.

Lucy (Asteroid Mission): https://www.nasa.gov/lucy

Image (mentioned), Video (mentioned), Text, Credits: NASA/Jamie Adkins/Southwest Research Institute, by Katherine Kretke.

Greetings, Orbiter.ch

CASC - Long March-2C launches three LEO communication test satellites

 







CASC - China Aerospace Science and Technology Corporation logo.


May 20, 2022

Long March-2C carrying three LEO communication test satellites liftoff

A Long March-2C launch vehicle launched three low Earth orbit (LEO) communication test satellites (颗低轨通信试验卫星) from the Jiuquan Satellite Launch Center, Gansu Province, northwest China, on 20 May 2022, at 10:30 UTC (18:30 local time).

Long March-2C launches three LEO communication test satellites

According to official sources, the satellites have entered the planned orbits and will “carry out tests and verifications of in-orbit communication technologies”.

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

Image, Video, Text, Credits: China Media Group(CMG)/China Central Television (CCTV)/China Aerospace Science and Technology Corporation (CASC)/SciNews/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

Space Station Science Highlights: Week of May 16, 2022

 







ISS - Expedition 67 Mission patch.


May 20, 2022

Crew members aboard the International Space Station conducted scientific investigations during the week of May 16 that included examining changes in carotid arteries during spaceflight, demonstrating wireless infrastructure for a wearable health monitoring system, and collecting measurements to track how crew members adapt to life in space.


Image above: This image shows an orbital sunset above the Atlantic Ocean off the coast of South Africa as the space station passed 266 miles overhead. Image Credit: NASA.

Here are details on some of the microgravity investigations currently taking place on the orbiting lab:

Keeping an eye on arteries

Vascular Aging, a Canadian Space Agency (CSA) investigation, collects data on vascular changes in astronauts using ultrasound images, blood samples, and wearable sensors. Crew members experience some physical changes similar to aging that occur more quickly in space than they do on Earth. These include changes to carotid arteries, which potentially represent a significant health risk on future long-duration space missions. This investigation could support development of ways to reduce those potential health risks as well as guide prevention measures and treatments for the effects of aging on Earth. During the week, crew members collected multiple data points for the investigation.

That’s a smart shirt


Animation above: ESA astronaut Samantha Cristoforetti conducts a breathing maneuver while wearing the smart shirt for Wireless Compose-2, which demonstrates wireless infrastructure for sensors that monitor astronaut health and data transmission to support control of free-flying robots. Animation Credit: NASA.

Wireless Compose-2, an investigation from ESA (European Space Agency), demonstrates wireless infrastructure for data collection and transmission in microgravity. The investigation includes analysis of how space affects the cardiovascular system, using a shirt with imbedded sensors. This technology could contribute to development of less intrusive ways to monitor the health of astronauts and people on the ground. Wireless Compose-2 also demonstrates hardware that could enable precise control of free-flying robotic systems in environments similar to the space station. This part of the investigation could contribute to technology that provides more precise control of free-flying robots. Crew members conducted sessions wearing the smart shirt during the week.

Setting the standard

Standard Measures collects a set of core measurements, including data on behavioral health and performance, cellular profiles and immunology, the microbiome, biochemistry markers, sensorimotor changes, and cardiovascular health. Researchers have collected these data from crew members throughout the life of the space station and use them to characterize how crew members adapt to living and working in space, to monitor countermeasure effectiveness, and to support future research on planetary missions. During the week, crew members collected and processed samples for the investigation.


Image above: The Expedition 67 crew poses for a portrait. Front row, NASA astronaut Jessica Watkins, left, and Russian space agency Roscosmos cosmonaut Sergey Korsakov, right. Back row, from left, are Roscosmos cosmonaut Denis Matveev; NASA astronauts Kjell Lindgren and Bob Hines; ESA astronaut Samantha Cristoforetti; and Roscosmos cosmonaut Oleg Artemyev. Image Credit: NASA.

Other investigations involving the crew:

- XROOTS uses hydroponic (liquid-based) and aeroponic (air-based) techniques to grow plants without traditional growth media, which could enable production of crops on a larger scale for future space exploration.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8088

- rHEALTH demonstration tests whether a modified commercial off-the-shelf device can accurately diagnose certain medical conditions in microgravity. Such a device could help crew members monitor their health on future deep-space exploration missions and improve access to diagnostic tests for patients in remote settings on Earth.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8467

- Acoustic Diagnostics, an investigation from ESA (European Space Agency), tests the hearing of crew members before, during, and after flight. While the symptoms of mild hearing impairment can be temporary, it is important to detect them as early as possible before they lead to more significant issues.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7898

- Lumina, an ESA investigation, demonstrates a dosimeter using optical fibers to monitor in real time the radiation dose received by crew members. Monitoring radiation exposure is key to crew safety on future space missions, and this technology also has potential applications in the medical and nuclear industries on Earth.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8444

- ESA’s ANITA-2 demonstrates a device that analyzes trace contaminants in the atmosphere aboard the space station. This monitoring is essential for future human exploration missions and can provide monitoring of air quality in closed environments on Earth as well.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7445

- ISS Ham Radio provides students, teachers, parents, and others the opportunity to communicate with astronauts using amateur radio units. Before a scheduled call, students learn about the station, radio waves, and other topics, and prepare a list of questions on topics they have researched.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=337

Space to Ground: Flight Test: 05/20/2022

The space station is a robust microgravity laboratory with a multitude of specialized research facilities and tools. Over more than two decades of continuous operation, it has supported many scientific breakthroughs from investigations spanning every major scientific discipline. The orbiting lab conveys benefits to future space exploration, advances basic and applied research on Earth, and provides a platform for a growing commercial presence in low-Earth orbit.

Related links:

Expedition 67: https://www.nasa.gov/mission_pages/station/expeditions/expedition67/index.html

Vascular Aging: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7644

Wireless Compose-2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8563

Standard Measures: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7711

ISS National Lab: https://www.issnationallab.org/

Spot the Station: https://spotthestation.nasa.gov/

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/overview.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Animation (mentioned), Images (mentioned), Video (NASA), Text, Credits: NASA/Ana Guzman/John Love, ISS Research Planning Integration Scientist Expedition 67.

Best regards, Orbiter.ch

Galaxies without dark matter perplex astronomers

 







Astrophysics logo.

 

 May 20, 2022

Researchers say a cosmic collision could have created two galaxies that don’t contain the mysterious substance — but others cast doubt on the claim.


Image above: This Hubble image captures a set of galaxies that are unusual because they seem not to have dark matter. Image Credits: NASA/ESA/P. van Dokkum, Yale Univ.

Astronomers think that galaxies cannot form without the gravitational pull of dark matter. So a trail of galaxies free of this mysterious material, with no obvious cause, would be a remarkable find. In a paper published in Nature on 18 May1, astronomers say they might have observed such a system — a line of 11 galaxies that don’t contain any dark matter, which could all have been created in the same ancient collision. But many of their peers are unconvinced that the claim is much more than a hypothesis.

This kind of system could be used to learn about how galaxies form, and about the nature of dark matter itself. “If proven right, this could certainly be exciting for galaxy formation. However, the jury is still out,” says Chervin Laporte, an astronomer at the University of Barcelona in Spain.

The finding centres on two galaxies described by Pieter van Dokkum at Yale University in New Haven, Connecticut, and his co-authors in 2018 and 2019. Their stars moved so slowly that the pull of dark matter was not needed to explain their orbits, so the team concluded that the galaxies contained no dark matter. The finding was controversial because the galaxies, named DF2 and DF4, seemed stable and different from the only other known dark-matter-free galaxies, which are new and short-lived, created in the arms of larger galaxies whose dark matter is being stripped by a neighbour. How DF2 and DF4 formed was a mystery.

Telltale trail

In the latest paper, van Dokkum’s team not only connects the two unusual galaxies, but says their properties are consistent with them being formed in a high-speed collision, eight billion years ago, that also spawned more such structures. “This single explanation explains so many odd things about these galaxies,” says van Dokkum.

The team borrowed its scenario from simulations originally created to explain unique features in larger-scale collisions between galaxy clusters. The researchers suggest that when two progenitor galaxies collided head on, their dark matter and stars would have sailed past each other; the dark matter would not have interacted, and the stars would have been too far apart to collide. But as the dark matter and stars sped on, gas in the space between the two galaxies’ stars would have crashed together, compacted and slowed down, leaving a trail of matter that later formed new galaxies with no dark matter.

Next, the researchers looked for such galaxies in the line between DF2 and DF4. They identified between three and seven new candidates for dark-matter-free galaxies, as well as strange, faint galaxies at either end, which could be the dark matter and stars remaining from the progenitor galaxies. “It was staring you in the face once you knew what to look for,” says van Dokkum.

If this picture proves to be true, it could help astronomers to understand how dark matter behaves, and to learn about the circumstances under which galaxies can form. Such a galactic collision might also be used as a “new laboratory” to understand whether dark matter interacts with itself, says Go Ogiya, an astronomer at Zhejiang University in Hangzhou, China.

Open questions

Although plausible, van Dokkum’s model describes just one of a number of ways that these galaxies could have been made, says Priyamvada Natarajan, an astrophysicist at Yale who is not a member of van Dokkum’s team. But it is intriguing and, crucially, makes testable predictions, she says.

Measurements of the precise distances and velocities of candidate galaxies could prove they are part of the same string and not just coincidentally along the same line of sight, says Michelle Collins, an astronomer at the University of Surrey in Guildford, UK. “For me, whether this is a real line or not is a big open question.”

Astronomers also need to measure the masses of the ghost galaxies at the ends of the line — the potential progenitor galaxies — to test whether they contain lots of dark matter, as the model predicts, adds Laporte.

Others question whether any exotic explanation is needed. Ignacio Trujillo, an astronomer at the Institute of Astrophysics of the Canary Islands in La Laguna, Spain, leads a team that proposes that DF2 and DF4 are closer to Earth than van Dokkum’s measurements suggest, and therefore contain more dark matter than was at first apparent.

Astronomers also need to see a reliable simulation showing that the scenario van Dokkum’s team describes is plausible, says Mireia Montes, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland. “For now, there are a lot of assumptions, but those are not supported by any simulation,” she says.

doi: https://doi.org/10.1038/d41586-022-01410-x

References

1. van Dokkum, P. et al. Nature 605, 435–439 (2022).
https://doi.org/10.1038%2Fs41586-022-04665-6

Image (mentioned), Text, Credits: Nature/Elizabeth Gibney.

Greetings, Orbiter.ch

jeudi 19 mai 2022

Liftoff! Atlas V Clears the Launch Pad with Boeing’s CST-100 Starliner Spacecraft

 










Boeing / NASA - Starliner Orbital Flight Test-2 (OFT-2) patch.


May 19, 2022


Image above: A United Launch Alliance Atlas V carrying Boeing’s CST-100 Starliner for Orbital Flight Test-2 lifts off at 6:54 p.m. EDT from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida on May 19, 2022. Photo Credit: NASA.

Booster ignition and liftoff of the United Launch Alliance Atlas V rocket carrying Boeing’s CST-100 Starliner spacecraft on NASA’s Orbital Flight Test-2 to the International Space Station. Launch occurred at 6:54 p.m. EDT from Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida.

Starliner OFT-2 launch

About one minute after launch, the Atlas V rocket achieved Mach 1. About two-and-a-half minutes into flight, a series of key events will begin to occur over the next few minutes. The Atlas V solid rocket boosters will fall away. The Atlas first-stage booster engine will cut off, followed by separation from the dual-engine Centaur second stage. The Centaur first main engine will start, followed by aeroskirt jettison. A few minutes later the Centaur engine will cut off.

Boeing’s Starliner Separates from Atlas V Centaur


Image above: The Boeing CST-100 Starliner separates from the Atlas V Centaur second stage on May 19, 2022. Photo Credit: NASA.

Boeing’s CST-100 Starliner has separated from the Atlas V Centaur and is flying on its own, embarking on its flight to the International Space Station. After a series of orbital adjustments, Starliner will be on course for rendezvous and docking with the space station at 7:10 p.m. on Friday, May 20.

OFT-2 Starliner’s orbital insertion maneuver

Boeing’s CST-100 Starliner crew capsule successfully performed the orbital insertion maneuver approximately 31 minutes after being launched by a United Launch Alliance Atlas V N22 launch vehicle, with a dual engine Centaur upper stage, from Space Launch Complex 41 (SLC-41), Cape Canaveral Air Force Station, Florida, on 19 May 2022, at 22:54 UTC (18:54 EDT). The Starliner crew capsule is scheduled to autonomously dock to the ISS on 20 May 2022, at 23:10 UTC (19:10 EDT).

Starliner Launches to Space Station on Uncrewed Flight Test for NASA

Boeing’s CST-100 Starliner is in orbit, heading for the International Space Station following launch Thursday of the next-generation spacecraft on a United Launch Alliance (ULA) Atlas V rocket on a mission designed to test the end-to-end capabilities of the crew-capable system as part of NASA’s Commercial Crew Program.

Starliner lifted off on NASA’s Boeing Orbital Flight Test-2 (OFT-2) at 6:54 p.m. EDT from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida. Following an orbital insertion burn 31 minutes later, Starliner was on its way for a rendezvous and docking with the space station.


Image above: A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft launches from Space Launch Complex 41, Thursday, May 19, 2022, at Cape Canaveral Space Force Station in Florida. Boeing’s Orbital Flight Test-2 (OFT-2) is Starliner’s second uncrewed flight test and will dock to the International Space Station as part of NASA's Commercial Crew Program. OFT-2 launched at 6:54 p.m. ET, and will serve as an end-to-end test of the system's capabilities. Image Credits: NASA/Joel Kowsky.

“I am so proud of the NASA, Boeing and United Launch Alliance teams who have worked so hard to see Starliner on its way to the International Space Station,” said NASA Administrator Bill Nelson. “Through adversity, our teams have continued to innovate for the benefit of our nation and all of humanity. I look forward to a successful end-to-end test of the Starliner spacecraft, which will help enable missions with astronauts aboard.”

Launch and orbital insertion are major milestones for the company’s second uncrewed flight, bringing the U.S. closer to having two independent crew systems flying missions to and from the space station.

Starliner is scheduled to dock to the forward port of the station’s Harmony module about 7:10 p.m. Friday, May 20. After a successful docking, the crew of Expedition 67 will open Starliner’s hatch about 11:45 a.m. Saturday, May 21. Coverage of docking and hatch opening will air live on NASA Television, the NASA app, and the agency’s website: http://www.nasa.gov/live

“I am incredibly grateful to our NASA, Boeing, and United Launch Alliance teams that have demonstrated persistence, resolve, and dedication to ensuring we were ready for launch today and for this flight test,” said Kathryn Lueders, NASA associate administrator for space operations at NASA Headquarters in Washington. “We have learned so much as we’ve worked together to prepare for this mission, and we look forward to watching the spacecraft arrive at the space station for the first time and continuing to learn and improve as we prepare to fly our astronauts on Starliner.”

For the flight test, Starliner is carrying about 500 pounds of NASA cargo and crew supplies and more than 300 pounds of Boeing cargo to the International Space Station. Following certification, NASA missions aboard Starliner will carry up to four crew members to the station, enabling the continued expansion of the crew and increasing the amount of science and research that can be performed aboard the orbiting laboratory.

OFT-2 will provide valuable data toward NASA certifying Boeing’s crew transportation system for regular flights with astronauts to and from the space station.

CST-100 Starliner. Animation Credit: Boeing

“We’ve learned a lot about the capability of our spacecraft and the resilience of our team since the first Starliner launch,” said Mark Nappi, vice president and program manager, Boeing Commercial Crew Program. “We still have a lot of operational testing ahead as we prepare to rendezvous with the space station, but we’re ready to demonstrate the system we’ve worked so hard on is capable of carrying astronauts to space.”

ULA controlled the launch of the Atlas V rocket from its Atlas Spaceflight Operations Center in Cape Canaveral. As Starliner ascended into space, Boeing commanded the spacecraft from its mission control center at NASA’s Kennedy Space Center in Florida. Boeing and ULA teams also provided support to controllers from Kennedy Space Center and Colorado, respectively, throughout the countdown to launch. NASA teams will monitor space station operations throughout the flight from Mission Control Center at the agency’s Johnson Space Center in Houston.

“We are proud of our partnership role with Boeing in NASA’s Commercial Crew Program and want to thank our mission partners as this is truly a collective accomplishment,” said Tory Bruno, president and CEO, United Launch Alliance. “The successful launch today marks the first critical step toward the future of humans spaceflight onboard an Atlas V and we look forward to the remainder of the mission and to safely flying astronauts in the future.”

Starliner is scheduled to depart the space station Wednesday, May 25, when it will undock and return to Earth, with a desert landing in the western U.S. The spacecraft will return with more than 600 pounds of cargo, including Nitrogen Oxygen Recharge System reusable tanks that provide breathable air to station crew members. The tanks will be refurbished on Earth and sent back to station on a future flight.

Related article:

What You Need to Know about NASA’s Boeing Orbital Flight Test-2
https://orbiterchspacenews.blogspot.com/2021/07/what-you-need-to-know-about-nasas.html

Related links:

Commercial Crew: https://www.nasa.gov/exploration/commercial/crew/index.html

Kennedy Space Center (KSC): https://www.nasa.gov/centers/kennedy/home/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Animation (mentioned), Videos (mentioned), Text, Credits: NASA/Linda Herridge/Gerelle Dodson/Joshua Finch/JSC/Dan Huot/KSC/Brittney Thorpe/Jennifer Wolfinger/NASA TV/SciNews/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

CLOUD discovers new way by which aerosols rapidly form and grow at high altitude

 







CERN - European Organization for Nuclear Research logo.


May 19, 2022

The resultant particles quickly spread around the globe, potentially influencing Earth’s climate on an intercontinental scale

View of the CLOUD experiment at CERN (Image: CERN)

Aerosol particles can form and grow in Earth’s upper troposphere in an unexpected way, reports the CLOUD collaboration in a paper1 published today in Nature. The new mechanism may represent a major source of cloud and ice seed particles in areas of the upper troposphere where ammonia is efficiently transported vertically, such as over the Asian monsoon regions.

Aerosol particles are known to generally cool the climate by reflecting sunlight back into space and by making clouds more reflective. However, how new aerosol particles form in the atmosphere remains relatively poorly known.

“Newly formed aerosol particles are ubiquitous throughout the upper troposphere, but the vapours and mechanisms that drive the formation of these particles are not well understood,” explains CLOUD spokesperson Jasper Kirkby. “With experiments performed under cold upper tropospheric conditions in CERN’s CLOUD chamber, we uncovered a new mechanism for extremely rapid particle formation and growth involving novel mixtures of vapours.”

Using mixtures of sulfuric acid, nitric acid and ammonia vapours in the chamber at atmospheric concentrations, the CLOUD team found that these three compounds form new particles synergistically at rates much faster than those for any combination of two of the compounds. The CLOUD researchers found that the three vapours together form new particles 10–1000 times faster than a sulfuric acid–ammonia mixture, which, from previous CLOUD measurements, was previously considered to be the dominant source of upper tropospheric particles. Once the three-component particles form, they can grow rapidly from the condensation of nitric acid and ammonia alone to sizes where they seed clouds.

Moreover, the CLOUD measurements show that these particles are highly efficient at seeding ice crystals, comparable to desert dust particles, which are thought to be the most widespread and effective ice seeds in the atmosphere. When a supercooled cloud droplet freezes, the resulting ice particle will grow at the expense of any unfrozen droplets nearby, so ice has a major influence on cloud microphysical properties and precipitation.

The CLOUD researchers went on to feed their measurements into global aerosol models that include vertical transport of ammonia by deep convective clouds. The models showed that, although the particles form locally in ammonia-rich regions of the upper troposphere such as over the Asian monsoon regions, they travel from Asia to North America in just three days via the subtropical jet stream, potentially influencing Earth’s climate on an intercontinental scale.

“Our results will improve the reliability of global climate models in accounting for aerosol formation in the upper troposphere and in predicting how the climate will change in the

future,” says Kirkby. “Once again, CLOUD is finding that anthropogenic ammonia has a major influence on atmospheric aerosol particles, and our studies are informing policies for future air pollution regulations.”

Atmospheric concentrations of sulfuric acid, nitric acid and ammonia were much lower in the pre-industrial era than they are now, and each is likely to follow different concentration trajectories under future air pollution controls. Ammonia in the upper troposphere originates from livestock and fertiliser emissions – which are unregulated at present – and is carried aloft in convective cloud droplets, which release their ammonia upon freezing.


Image above: Simulation of aerosol particle formation during the Asian monsoon in a global aerosol model with efficient vertical transport of ammonia into the upper troposphere. Including a mixture of sulfuric acid, nitric acid and ammonia enhances upper-tropospheric particle number concentrations over the Asian monsoon region by a factor of 3–5 compared with the same model with only sulfuric acid and ammonia. (Image: CLOUD collaboration).

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Reference:

1) Wang, M. et al. Synergistic HNO3–H2SO4–NH3 upper tropospheric particle formation. Nature, doi:10.1038/s41586-022-04605-4 (2022).
https://www.nature.com/articles/s41586-022-04605-4

Related links:

CLOUD: https://home.cern/science/experiments/cloud

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

Images (mentioned), Text, Credits: CERN/CLOUD collaboration.

Best regards, Orbiter.ch

A Dazzling Hubble Collection of Supernova Host Galaxies

 







NASA / ESA - Hubble Space Telescope (HST) patch.


May 19, 2022

A Dazzling Hubble Collection of Supernova Host Galaxies

Spanning from 2003 to 2021, this collection of images from the NASA/ESA Hubble Space Telescope features galaxies that are all hosts to both Cepheid variables and supernovae. These two celestial phenomena are both crucial tools used by astronomers to determine astronomical distance, and have been used to refine our measurement of Hubble’s constant, the expansion rate of the Universe.

Hubble Captures Supernova in NGC 2525

Each of the images in this special collection features a spiral galaxy that hosts both Cepheid variables and a special class of supernovae, two remarkable stellar phenomena that on the face of it do not have much in common: Cepheid variables are pulsating stars that regularly brighten and dim and type Ia supernovae are the catastrophic explosions that mark the death throes of a hot, dense white dwarf star.  However, both can be used by astronomers to measure the distance to an astronomical object.

Spirals Are In This Season

Establishing the distance of a celestial body is an enormous challenge for astronomers; it can be difficult to distinguish between objects that are dim and relatively close to the Earth and those which are bright and distant. To help overcome this challenge, astronomers have developed what is known as the cosmic distance ladder, a series of distance-determining methods, organised by the relative distances that they can measure. Two important steps in this ladder are Cepheid variables and supernovae: Cepheid variables because the period with which they pulsate can be used to calculate their distance; and supernovae because every type Ia supernova explosion reaches the same known luminosity, meaning that its brightness as viewed from Earth can be used to derive its distance. All the galaxies presented in this collection host Cepheid variables and have had at least one type Ia supernova explosion occur in them within the last 40 years. One of the galaxies, NGC 2525, even contained a supernova that was caught in real time in a remarkable timelapse.

Four Filter Fusion

Even before it was launched, one of Hubble’s main science goals was to observe Cepheid variables and supernovae. These observations can help measure the expansion rate of the Universe, a value which astronomers call the Hubble constant. Generations of astronomers have refined this value over almost 30 years using data from more than 1000 hours of Hubble time. Most recently, a team of astronomers called SH0ES [1] used observations of all the supernovae seen by Hubble in the last 40 years  — including those in the galaxies pictured here — to determine the value of the Hubble constant as 73.04 ± 1:04 kms-1 Mpc-1 [2].

Galactic Conjunction

“This is what the Hubble Space Telescope was built to do. You are getting the standard measure for the Universe from the gold standard of telescopes,” said Noble Laureate Adam Riess of Johns Hopkins University in Baltimore, Maryland, who leads the SH0ES Team. “This is Hubble’s magnum opus.”

A Galactic Powerhouse

Interestingly, the expansion rate determined from observational data from telescopes is significantly different from the value predicted by our current standard cosmological model of the Universe. The richness of the Hubble data means that this is vanishingly unlikely to have happened by a chance selection of misleading observations.

A Dazzling Hubble Collection of Supernova Host Galaxies

The wide collection of Cepheid variable and supernovae-hosting galaxies observed by Hubble were picked out in six different proposals for observing time with the telescope [3]. Whilst these proposals were part of Hubble’s decade-long quest to precisely measure the expansion rate of the Universe, the observations also produced a spate of beautiful galactic portraits, such as those of NGC 5643, NGC 7329, and NGC 3254. Still others have previously been featured in Hubble Pictures of the Week and other releases, including NGC 691, NGC 1559, NGC 2525, NGC 2608 and NGC 3147.

Notes

[1] SH0ES stands for “Supernova, H0, for the Equation of State of Dark Energy”

[2] The units of the Hubble constant — kms-1 Mpc-1 — are kilometres per second per megaparsec. If you multiply the distance to an astronomical object in megaparsecs by the Hubble constant you obtain the speed at which that object is receding from Earth as a result of the expansion of the Universe.

[3] The demand for observation time with Hubble is still extremely high, even after more than 30 years since the telescope’s launch, and in order to secure time astronomers need to justify in a written proposal why their work will be helpful and important to the astronomical community.

More information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The complete list of galaxies imaged above which are hosts to both Cepheid variables and supernovae consists of: NGC 691, NGC 1559, NGC 2525, NGC 2608, NGC 3147, NGC 3583, NGC 5468, NGC 5643, NGC 5861, NGC 7541, Mrk 1337, NGC 4680, NGC 5728, NGC 7329, NGC 7678, M101, NGC 1015, NGC 1309, NGC 1365, NGC 1448, NGC 3021, NGC 3370, NGC 3447, NGC 4424, NGC 5917, NGC 7250, UGC 9391, M106, NGC 3982, NGC 4536, NGC 4639, NGC 5584, The Antennae Galaxies, NGC 2442, NGC 3972, NGC 105 and NGC 3254.

The SH0ES team of astronomers in this study consists of Adam G. Riess (Space Telescope Science Institute and the Department of Physics and Astronomy, Johns Hopkins University), Wenlong Yuan (Department of Physics and Astronomy, Johns Hopkins University), Lucas M. Macri (George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University), Dan Scolnic (Department of Physics, Duke University), Dillon Brout (Center for Astrophysics, Harvard & Smithsonian), Stefano Casertano (Space Telescope Science Institute), David O. Jones (Department of Astronomy & Astrophysics, University of California, Santa Cruz), Yukei Murakami (Department of Physics and Astronomy, Johns Hopkins University), Louise Breuval (Department of Physics and Astronomy, Johns Hopkins University), Thomas G. Brink (Department of Astronomy, University of California, Berkeley), Alexei V. Filippenko ( Department of Astronomy, University of California, Berkeley and Miller Institute for Basic Research in Science, University of California, Berkeley), Samantha Hoffmann (Space Telescope Science Institute), Saurabh W. Jha (Department of Physics and Astronomy, Rutgers, the State University of New Jersey), W. D'arcy Kenworthy (Department of Physics and Astronomy, Johns Hopkins University), John Mackenty (Space Telescope Science Institute), Benjamin E. Stahl (Department of Astronomy, University of California, Berkeley) and Weikang Zheng (Department of Astronomy, University of California, Berkeley).

Links:

A Dazzling Hubble Collection of Supernova Host Galaxies
https://esahubble.org/videos/heic2208a/

Images of Hubble: https://esahubble.org/images/archive/category/spacecraft/
 
Hubblesite release: https://hubblesite.org/contents/news-releases/2022/news-2022-005

Science paper: https://arxiv.org/pdf/2112.04510.pdf

ESA's Hubble Website: https://esahubble.org/

Images Credits: NASA, ESA/SA/Hubble & NASA, A. Riess and the SH0ES team/Acknowledgment: Mahdi Zamani/Video Credits: Directed by: Bethany Downer and Nico Bartmann/Editing: Nico Bartmann/Web and technical support: Enciso Systems/Written by: Bethany Downer/Music: Mylonite - Breath of my Soul/Footage and photos: NASA, ESA/Text Credits: ESA/Hubble Chief Science Communications Officer, Bethany Downer.

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