Category Archives: Education

ESO: Black hole discovered in star cluster outside the Milky Way

November 11, 2021 TopSpacer

A new report from ESO (European Southern Observatory):

Black hole found hiding in star cluster outside our galaxy

This artist’s impression shows a compact black hole 11 times as massive as the Sun and the five-solar-mass star orbiting it. The two objects are located in NGC 1850, a cluster of thousands of stars roughly 160 000 light-years away in the Large Magellanic Cloud, a Milky Way neighbour. The distortion of the star’s shape is due to the strong gravitational force exerted by the black hole. Not only does the black hole’s gravitational force distort the shape of the star, but it also influences its orbit. By looking at these subtle orbital effects, a team of astronomers were able to infer the presence of the black hole, making it the first small black hole outside of our galaxy to be found this way. For this discovery, the team used the Multi Unit Spectroscopic Explorer (MUSE) instrument at ESO’s Very Large Telescope in Chile.

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have discovered a small black hole outside the Milky Way by looking at how it influences the motion of a star in its close vicinity. This is the first time this detection method has been used to reveal the presence of a black hole outside of our galaxy. The method could be key to unveiling hidden black holes in the Milky Way and nearby galaxies, and to help shed light on how these mysterious objects form and evolve.

The newly found black hole was spotted lurking in NGC 1850, a cluster of thousands of stars roughly 160 000 light-years away in the Large Magellanic Cloud, a neighbour galaxy of the Milky Way.

“Similar to Sherlock Holmes tracking down a criminal gang from their missteps, we are looking at every single star in this cluster with a magnifying glass in one hand trying to find some evidence for the presence of black holes but without seeing them directly,”

says Sara Saracino from the Astrophysics Research Institute of Liverpool John Moores University in the UK, who led the research now accepted for publication in Monthly Notices of the Royal Astronomical Society.

“The result shown here represents just one of the wanted criminals, but when you have found one, you are well on your way to discovering many others, in different clusters.”

This first “criminal” tracked down by the team turned out to be roughly 11 times as massive as our Sun. The smoking gun that put the astronomers on the trail of this black hole was its gravitational influence on the five-solar-mass star orbiting it.

This image shows NGC1850, a cluster of thousands of stars roughly 160 000 light-years away in the Large Magellanic Cloud, a Milky Way neighbour. The reddish filaments surrounding the cluster, made of vast clouds of hydrogen, are believed to be the remnants of supernova explosions. The image is an overlay of observations conducted in visible light with ESO’s Very Large Telescope (VLT) and NASA/ESA’s Hubble Space Telescope (HST). The VLT captured the wide field of the image and the filaments, while the central cluster was imaged by the HST. Among many stars, this cluster is home to a black hole 11 times as massive as the Sun and to a five-solar-mass star orbiting it. By looking at the star’s orbit, a team of astronomers were able to infer the presence of the black hole, making it the first small black hole outside of our galaxy to be found this way. For this discovery, the team used the Multi Unit Spectroscopic Explorer (MUSE) instrument at the VLT.

Astronomers have previously spotted such small, “stellar-mass” black holes in other galaxies by picking up the X-ray glow emitted as they swallow matter, or from the gravitational waves generated as black holes collide with one another or with neutron stars.

However, most stellar-mass black holes don’t give away their presence through X-rays or gravitational waves.

“The vast majority can only be unveiled dynamically,”

says Stefan Dreizler, a team member based at the University of Göttingen in Germany.

“When they form a system with a star, they will affect its motion in a subtle but detectable way, so we can find them with sophisticated instruments.”

This dynamical method used by Saracino and her team could allow astronomers to find many more black holes and help unlock their mysteries.

“Every single detection we make will be important for our future understanding of stellar clusters and the black holes in them,”

says study co-author Mark Gieles from the University of Barcelona, Spain.

The detection in NGC 1850 marks the first time a black hole has been found in a young cluster of stars (the cluster is only around 100 million years old, a blink of an eye on astronomical scales). Using their dynamical method in similar star clusters could unveil even more young black holes and shed new light on how they evolve. By comparing them with larger, more mature black holes in older clusters, astronomers would be able to understand how these objects grow by feeding on stars or merging with other black holes. Furthermore, charting the demographics of black holes in star clusters improves our understanding of the origin of gravitational wave sources.

To carry out their search, the team used data collected over two years with the Multi Unit Spectroscopic Explorer (MUSE) mounted at ESO’s VLT, located in the Chilean Atacama Desert.

“MUSE allowed us to observe very crowded areas, like the innermost regions of stellar clusters, analysing the light of every single star in the vicinity. The net result is information about thousands of stars in one shot, at least 10 times more than with any other instrument,”

says co-author Sebastian Kamann, a long-time MUSE expert based at Liverpool’s Astrophysics Research Institute. This allowed the team to spot the odd star out whose peculiar motion signalled the presence of the black hole. Data from the University of Warsaw’s Optical Gravitational Lensing Experiment and from the NASA/ESA Hubble Space Telescope enabled them to measure the mass of the black hole and confirm their findings.

ESO’s Extremely Large Telescope in Chile, set to start operating later this decade, will allow astronomers to find even more hidden black holes.

“The ELT will definitely revolutionise this field,” says Saracino. “It will allow us to observe stars considerably fainter in the same field of view, as well as to look for black holes in globular clusters located at much greater distances.”

ESO’s VISTA telescope reveals a remarkable image of the Large Magellanic Cloud, one of our nearest galactic neighbours. VISTA has been surveying this galaxy and its sibling the Small Magellanic Cloud, as well as their surroundings, in unprecedented detail. This survey allows astronomers to observe a large number of stars, opening up new opportunities to study stellar evolution, galactic dynamics, and variable stars.

Links

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Night sky highlights for November 2021

November 2, 2021 TopSpacer

** What’s Up: November 2021 Skywatching Tips from NASA – NASA JPL

What are some skywatching highlights in November 2021?

Enjoy the Moon and planets after sunset all month, plus a lunar eclipse! A partial lunar eclipse will be visible to much of the world on Nov. 18 and 19. Also, the familiar stars of Northern Hemisphere winter (or Southern summer) are returning to late night skies. In particular, note that several destinations of NASA’s Lucy mission are located near the Pleiades.

Additional information about topics covered in this episode of What’s Up, along with still images from the video, and the video transcript, are available at https://solarsystem.nasa.gov/whats-up….

** Tonight’s Sky: November – Space Telescope Science Institute – Tonight’s Sky

In November, hunt for the fainter constellations of fall, including Pisces, Aries, and Triangulum. They will guide you to find several galaxies and a pair of white stars. Stay tuned for space-based views of spiral galaxy M74 and the Triangulum Galaxy, which are shown in visible, infrared, and ultraviolet light.

** What to see in the night sky: November 2021 – BBC Sky at Night Magazine

What can you see in the night sky tonight? Find out what stars, planets, constellations and deep-sky objects are visible this month.

** What’s in the Night Sky November 2021 #WITNS – Alyn Wallace

** Night Sky Notebook March 2021 – Peter Detterline

** See also:

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Asteroids & Comets, Astronomy, Education

ESO: VLT images 42 of the largest asteroids

October 12, 2021 TopSpacer

The latest report from ESO (European Southern Observatory):

Meet the 42:
ESO images some of the biggest asteroids in our Solar System

This image depicts 42 of the largest objects in the asteroid belt, located between Mars and Jupiter. Most of them are larger than 100 kilometres, with the two biggest asteroids being Ceres and Vesta, which are around 940 and 520 kilometres in diameter, and the two smallest ones being Urania and Ausonia, each only about 90 kilometres. The images of the asteroids have been captured with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO’s Very Large Telescope.

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile, astronomers have imaged 42 of the largest objects in the asteroid belt, located between Mars and Jupiter. Never before had such a large group of asteroids been imaged so sharply. The observations reveal a wide range of peculiar shapes, from spherical to dog-bone, and are helping astronomers trace the origins of the asteroids in our Solar System.

The detailed images of these 42 objects are a leap forward in exploring asteroids, made possible thanks to ground-based telescopes, and contribute to answering the ultimate question of life, the Universe, and everything [1].

“Only three large main belt asteroids, Ceres, Vesta and Lutetia, have been imaged with a high level of detail so far, as they were visited by the space missions Dawn and Rosetta of NASA and the European Space Agency, respectively,”

explains Pierre Vernazza, from the Laboratoire d’Astrophysique de Marseille in France, who led the asteroid study published today in Astronomy & Astrophysics.

“Our ESO observations have provided sharp images for many more targets, 42 in total.”

The previously small number of detailed observations of asteroids meant that, until now, key characteristics such as their 3D shape or density had remained largely unknown. Between 2017 and 2019, Vernazza and his team set out to fill this gap by conducting a thorough survey of the major bodies in the asteroid belt.

Most of the 42 objects in their sample are larger than 100 km in size; in particular, the team imaged nearly all of the belt asteroids larger than 200 kilometres, 20 out of 23. The two biggest objects the team probed were Ceres and Vesta, which are around 940 and 520 kilometres in diameter, whereas the two smallest asteroids are Urania and Ausonia, each only about 90 kilometres.

These images have been captured with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO’s Very Large Telescope as part of a programme that surveyed 42 of the largest asteroids in our Solar System. They show Ceres and Vesta, the two largest objects in the asteroid belt between Mars and Jupiter, approximately 940 and 520 kilometres in diameter. These two asteroids are also the two most massive in the sample.

By reconstructing the objects’ shapes, the team realised that the observed asteroids are mainly divided into two families. Some are almost perfectly spherical, such as Hygiea and Ceres, while others have a more peculiar, “elongated” shape, their undisputed queen being the “dog-bone” asteroid Kleopatra.

By combining the asteroids’ shapes with information on their masses, the team found that the densities change significantly across the sample. The four least dense asteroids studied, including Lamberta and Sylvia, have densities of about 1.3 grams per cubic centimetre, approximately the density of coal. The highest, Psyche and Kalliope, have densities of 3.9 and 4.4 grammes per cubic centimetre, respectively, which is higher than the density of diamond (3.5 grammes per cubic centimetre).

This large difference in density suggests the asteroids’ composition varies significantly, giving astronomers important clues about their origin.

“Our observations provide strong support for substantial migration of these bodies since their formation. In short, such tremendous variety in their composition can only be understood if the bodies originated across distinct regions in the Solar System,”

explains Josef Hanuš of the Charles University, Prague, Czech Republic, one of the authors of the study. In particular, the results support the theory that the least dense asteroids formed in the remote regions beyond the orbit of Neptune and migrated to their current location.

These findings were made possible thanks to the sensitivity of the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument mounted on ESO’s VLT [2].

“With the improved capabilities of SPHERE, along with the fact that little was known regarding the shape of the largest main belt asteroids, we were able to make substantial progress in this field,”

says co-author Laurent Jorda, also of the Laboratoire d’Astrophysique de Marseille.

Astronomers will be able to image even more asteroids in fine detail with ESO’s upcoming Extremely Large Telescope (ELT), currently under construction in Chile and set to start operations later this decade.

“ELT observations of main-belt asteroids will allow us to study objects with diameters down to 35 to 80 kilometres, depending on their location in the belt, and craters down to approximately 10 to 25 kilometres in size,”

says Vernazza.

“Having a SPHERE-like instrument at the ELT would even allow us to image a similar sample of objects in the distant Kuiper Belt. This means we’ll be able to characterise the geological history of a much larger sample of small bodies from the ground.”

This poster shows 42 of the largest objects in the asteroid belt, located between Mars and Jupiter (orbits not to scale). The images in the outermost circle of this infographic have been captured with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO’s Very Large Telescope. The asteroid sample features 39 objects larger than 100 kilometres in diameter, including 20 larger than 200 kilometres. The poster highlights a few of the objects, including Ceres (the largest asteroid in the belt), Urania (the smallest one imaged), Kalliope (the densest imaged) and Lutetia, which was visited by the European Space Agency’s Rosetta mission.

Notes

[1] In The Hitchhiker’s Guide to the Galaxy by Douglas Adams, the number 42 is the answer to the “Ultimate Question of Life, the Universe, and Everything.” Today, 12 October 2021, is the 42^nd anniversary of the publication of the book.

[2] All observations were conducted with the Zurich IMaging POLarimeter (ZIMPOL), an imaging polarimeter subsystem of the SPHERE instrument that operates at visible wavelengths.

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Night sky highlights for October 2021

October 3, 2021 TopSpacer

** ** What’s Up: October 2021 Skywatching Tips from NASA – NASA JPL

What are some skywatching highlights in October 2021? See several groupings of the Moon, planets, and stars at sunrise and sunset. Then get to know two bright stars that are part of a special group: along with a handful of others, they take turns with Polaris as North Star over thousands of years. Plus, Oct. 16 is International Observe the Moon Night! Details: https://moon.nasa.gov/observe Additional information about topics covered in this episode of What’s Up, along with still images from the video, and the video transcript, are available at https://solarsystem.nasa.gov/whats-up….

** Tonight’s Sky: March – Space Telescope Science Institute – Tonight’s Sky

Crisp, clear October nights are full of celestial showpieces. Find Pegasus, the flying horse of Greek myth, to pinpoint dense globular star clusters and galaxies, and keep watching for space-based views of M15, NGC 7331, and the Andromeda Galaxy.

** What to see in the night sky: March 2021 – BBC Sky at Night Magazine

What’s in the night sky tonight? Astronomers Pete Lawrence and Paul Abel guide us through October’s night-sky highlights.

** What’s in the Night Sky October 2021 #WITNS | Orionid Meteor Shower | Draconid Meteor Shower – Alyn Wallace

** Night Sky Notebook October 2021 – Peter Detterline

** See also:

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Education, Rockets, Space Systems

Geared Up for Launch – Immortal Data & NM Tech

September 18, 2021 TopSpacer

An update from Immortal Data on the partnership with students at the New Mexico Institute of Mining and Technology on a sub-orbital rocket project:

Geared Up for Launch:
Four Years of Space Engineering Takes Flight

August, 30, 2021 (New Mexico) – Innovation works hard behind the scenes, often for years, before its accomplishments see the light of day. This year marks an exciting one for Immortal Data and the students of the New Mexico Institute of Mining and Technology, as their industrial partnership is finally set to take off, with all their hard work on board. Since 2017, IDI and NM Tech students have toiled long hours, developing the payload mounting and attaching system for sub-orbital flight, using extremely strict weight and volume guidelines. Their combined efforts have resulted in a payload that not only holds IDI’s data acquisition and logging system “microDAQ and ShipsStore,” but also includes structural health monitoring capabilities.

Structural Health Monitoring is an important technology that improves flight safety and reduces operation cost of future space systems. By monitoring structural conditions in real time, information on changes and damage can be reported immediately to the support team, which allows fast decisions to be made.

According to Dr. Andrei Zagrai,

“We believe that structural health monitoring will be one of key components in re-usability of future space vehicles. We are very excited to demonstrate its feasibility and integration with the blackbox system developed by Immortal Data. It is a great opportunity to test our ideas during sub-orbital space flight.”

This partnership has been a great opportunity for not only Immortal Data, but also for their partners at NMT. Students have been able to participate in a project that will reshape the future of space safety standards.

“This project is also an excellent example of collaboration between the institute and a commercial company as it has both educational and research objectives. We have an undergraduate student team which helped to design and fabricate payload and gained much experience interacting with space engineers at Immortal Data. A graduate student and a former New Mexico Tech graduate were involved in design, implementation and validation of SHM experiment further advancing research and engineering solutions for space vehicles. We hope that our joint work will help to make spaceflight safer and affordable to everyone.”

Through blended endeavors of passion and drive, NM Tech students and IDI have crafted a piece of technology that will impact the future of space engineering for years to come. IDI ShipStore’s patented solution to accumulate, store, and share sensor data in real time, combined with the enclosure designed by NMT to withstand the rigorous stress of a space launch, is a huge achievement for both parties involved. Immortal Data will be delivering the payload this month in anticipation of the sub-orbital flight scheduled to take place in November. They continue to prove their commitment to safety in space and to the space community.About Immortal Data: Immortal Data is an affordable solution to the data collection and recovery demands of the burgeoning and budget-minded private space craft industry.