Category Archives: Education

Astronomy, Education

ESO: Sharpest images yet of stars orbiting Milky Way’s supermassive black hole

A new report from the European Southern Observatory (Watch stars move around the Milky Way’s supermassive black hole in deepest images yet | ESO)

Watch stars move around the Milky Way’s supermassive black hole
in deepest images yet

These annotated images, obtained with the GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) between March and July 2021, show stars orbiting very close to Sgr A*, the supermassive black hole at the heart of the Milky Way. One of these stars, named S29, was observed as it was making its closest approach to the black hole at 13 billion kilometres, just 90 times the distance between the Sun and Earth. Another star, named S300, was detected for the first time in the new VLTI observations. To obtain the new images, the astronomers used a machine-learning technique, called Information Field Theory. They made a model of how the real sources may look, simulated how GRAVITY would see them, and compared this simulation with GRAVITY observations. This allowed them to find and track stars around Sagittarius A* with unparalleled depth and accuracy.

The European Southern Observatory’s Very Large Telescope Interferometer (ESO’s VLTI) has obtained the deepest and sharpest images to date of the region around the supermassive black hole at the centre of our galaxy. The new images zoom in 20 times more than what was possible before the VLTI and have helped astronomers find a never-before-seen star close to the black hole. By tracking the orbits of stars at the centre of our Milky Way, the team has made the most precise measurement yet of the black hole’s mass.

“We want to learn more about the black hole at the centre of the Milky Way, Sagittarius A*: How massive is it exactly? Does it rotate? Do stars around it behave exactly as we expect from Einstein’s general theory of relativity? The best way to answer these questions is to follow stars on orbits close to the supermassive black hole. And here we demonstrate that we can do that to a higher precision than ever before,”

explains Reinhard Genzel, a director at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany who was awarded a Nobel Prize in 2020 for Sagittarius A* research. Genzel and his team’s latest results, which expand on their three-decade-long study of stars orbiting the Milky Way’s supermassive black hole, are published today in two papers in Astronomy & Astrophysics.

On a quest to find even more stars close to the black hole, the team, known as the GRAVITY collaboration, developed a new analysis technique that has allowed them to obtain the deepest and sharpest images yet of our Galactic Centre.

“The VLTI gives us this incredible spatial resolution and with the new images we reach deeper than ever before. We are stunned by their amount of detail, and by the action and number of stars they reveal around the black hole,”

explains Julia Stadler, a researcher at the Max Planck Institute for Astrophysics in Garching who led the team’s imaging efforts during her time at MPE. Remarkably, they found a star, called S300, which had not been seen previously, showing how powerful this method is when it comes to spotting very faint objects close to Sagittarius A*.

With their latest observations, conducted between March and July 2021, the team focused on making precise measurements of stars as they approached the black hole. This includes the record-holder star S29, which made its nearest approach to the black hole in late May 2021. It passed it at a distance of just 13 billion kilometres, about 90 times the Sun-Earth distance, at the stunning speed of 8740 kilometres per second. No other star has ever been observed to pass that close to, or travel that fast around, the black hole.

The team’s measurements and images were made possible thanks to GRAVITY, a unique instrument that the collaboration developed for ESO’s VLTI, located in Chile. GRAVITY combines the light of all four 8.2-metre telescopes of ESO’s Very Large Telescope (VLT) using a technique called interferometry. This technique is complex,

“but in the end you arrive at images 20 times sharper than those from the individual VLT telescopes alone, revealing the secrets of the Galactic Centre,”

says Frank Eisenhauer from MPE, principal investigator of GRAVITY.

“Following stars on close orbits around Sagittarius A* allows us to precisely probe the gravitational field around the closest massive black hole to Earth, to test General Relativity, and to determine the properties of the black hole,”

explains Genzel. The new observations, combined with the team’s previous data, confirm that the stars follow paths exactly as predicted by General Relativity for objects moving around a black hole of mass 4.30 million times that of the Sun. This is the most precise estimate of the mass of the Milky Way’s central black hole to date. The researchers also managed to fine-tune the distance to Sagittarius A*, finding it to be 27 000 light-years away.

This visible light wide-field view shows the rich star clouds in the constellation of Sagittarius (the Archer) in the direction of the centre of our Milky Way galaxy. The entire image is filled with vast numbers of stars — but far more remain hidden behind clouds of dust and are only revealed in infrared images. This view was created from photographs in red and blue light and forming part of the Digitized Sky Survey 2. The field of view is approximately 3.5 degrees x 3.6 degrees.

To obtain the new images, the astronomers used a machine-learning technique, called Information Field Theory. They made a model of how the real sources may look, simulated how GRAVITY would see them, and compared this simulation with GRAVITY observations. This allowed them to find and track stars around Sagittarius A* with unparalleled depth and accuracy. In addition to the GRAVITY observations, the team also used data from NACO and SINFONI, two former VLT instruments, as well as measurements from the Keck Observatory and NOIRLab’s Gemini Observatory in the US.

GRAVITY will be updated later this decade to GRAVITY+, which will also be installed on ESO’s VLTI and will push the sensitivity further to reveal fainter stars even closer to the black hole. The team aims to eventually find stars so close that their orbits would feel the gravitational effects caused by the black hole’s rotation. ESO’s upcoming Extremely Large Telescope (ELT), under construction in the Chilean Atacama Desert, will further allow the team to measure the velocity of these stars with very high precision.

“With GRAVITY+’s and the ELT’s powers combined, we will be able to find out how fast the black hole spins,” says Eisenhauer. “Nobody has been able to do that so far.”

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Astronomy, Education

ESO: VLT spots planet orbiting most massive star pair so far

The latest report from the European Southern Observatory (ESO):

ESO telescope images planet around most massive star pair to date

This image shows the most massive planet-hosting star pair to date, b Centauri, and its giant planet b Centauri b. This is the first time astronomers have directly observed a planet orbiting a star pair this massive and hot.  The star pair, which has a total mass of at least six times that of the Sun, is the bright object in the top left corner of the image, the bright and dark rings around it being optical artefacts. The planet, visible as a bright dot in the lower right of the frame, is ten times as massive as Jupiter and orbits the pair at 100 times the distance Jupiter orbits the Sun. The other bright dot in the image (top right) is a background star. By taking different images at different times, astronomers were able to distinguish the planet from the background stars.  The image was captured by the SPHERE instrument on ESO’s Very Large Telescope and using a coronagraph, which blocked the light from the massive star system and allowed astronomers to detect the faint planet.

The European Southern Observatory’s Very Large Telescope (ESO’s VLT) has captured an image of a planet orbiting b Centauri, a two-star system that can be seen with the naked eye. This is the hottest and most massive planet-hosting star system found to date, and the planet was spotted orbiting it at 100 times the distance Jupiter orbits the Sun. Some astronomers believed planets could not exist around stars this massive and this hot — until now.

“Finding a planet around b Centauri was very exciting since it completely changes the picture about massive stars as planet hosts,”

explains Markus Janson, an astronomer at Stockholm University, Sweden and first author of the new study published online today in Nature.

Located approximately 325 light-years away in the constellation Centaurus, the b Centauri two-star system (also known as HIP 71865) has at least six times the mass of the Sun, making it by far the most massive system around which a planet has been confirmed. Until now, no planets had been spotted around a star more than three times as massive as the Sun.

Most massive stars are also very hot, and this system is no exception: its main star is a so-called B-type star that is over three times as hot as the Sun. Owing to its intense temperature, it emits large amounts of ultraviolet and X-ray radiation.

The large mass and the heat from this type of star have a strong impact on the surrounding gas, that should work against planet formation. In particular, the hotter a star is, the more high-energy radiation it produces, which causes the surrounding material to evaporate faster.

“B-type stars are generally considered as quite destructive and dangerous environments, so it was believed that it should be exceedingly difficult to form large planets around them,”

Janson says.

But the new discovery shows planets can in fact form in such severe star systems.

“The planet in b Centauri is an alien world in an environment that is completely different from what we experience here on Earth and in our Solar System,”

explains co-author Gayathri Viswanath, a PhD student at Stockholm University.

“It’s a harsh environment, dominated by extreme radiation, where everything is on a gigantic scale: the stars are bigger, the planet is bigger, the distances are bigger.”

Indeed, the planet discovered, named b Centauri (AB)b or b Centauri b, is also extreme. It is 10 times as massive as Jupiter, making it one of the most massive planets ever found. Moreover, it moves around the star system in one of the widest orbits yet discovered, at a distance a staggering 100 times greater than the distance of Jupiter from the Sun. This large distance from the central pair of stars could be key to the planet’s survival.

This artist’s impression shows a close up of the planet b Centauri b, which orbits a binary system with mass at least six times that of the Sun. This is the most massive and hottest planet-hosting star system found to date. The planet is ten times as massive as Jupiter and orbits the two-star system at 100 times the distance Jupiter orbits the Sun.

These results were made possible thanks to the sophisticated Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) mounted on ESO’s VLT in Chile. SPHERE has successfully imaged several planets orbiting stars other than the Sun before, including taking the first ever-image of two planets orbiting a Sun-like star.

However, SPHERE was not the first instrument to image this planet. As part of their study, the team looked into archival data on the b Centauri system and discovered that the planet had actually been imaged more than 20 years ago by the ESO 3.6-m telescope, though it was not recognised as a planet at the time.

With ESO’s Extremely Large Telescope (ELT), due to start observations later this decade, and with upgrades to the VLT, astronomers may be able to unveil more about this planet’s formation and features.

“It will be an intriguing task to try to figure out how it might have formed, which is a mystery at the moment,”

concludes Janson.

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Astronomy, Education, Space participation

Night sky highlights for December 2021

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

What are some skywatching highlights in December 2021? See three planets after sunset, but say goodbye to Venus as the “Evening Star” at the end of the month. Then have a hunt for newly discovered Comet Leonard in the early morning through mid-month. Finally, get up early on Dec. 14 to watch for Geminid meteors after local moonset, around 2 a.m. 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: December– Space Telescope Science Institute – Tonight’s Sky

Step outside on a cold December night when the stars shine bright to find the Big Dipper, Cassiopeia, and Cepheus. They will help you locate a binary star system, a fan-shaped open star cluster, and a variable star. Stay tuned for space-based views of a ragged spiral galaxy, an open star cluster, and an edge-on galaxy.

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

What can you see in the night sky tonight? Pete Lawrence and Paul Abel December 2021’s night-sky highlights.

** What’s in the Night Sky December 2021 #WITNS | Comet Leonard | Geminid Meteor Shower | Solar Eclipse – Alyn Wallace

** Night Sky Notebook December 2021 – Peter Detterline

** See also:

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Astronomy, Education

ESO: VLT uncovers closest pair of supermassive black holes yet found

The latest report from  ESO (European Southern Observatory):

ESO telescope uncovers closest pair of supermassive black holes yet

This image shows close-up (left) and wide (right) views of the two bright galactic nuclei, each housing a supermassive black hole, in NGC 7727, a galaxy located 89 million light-years away from Earth in the constellation Aquarius. Each nucleus consists of a dense group of stars with a supermassive black hole at its centre. The two black holes are on a collision course and form the closest pair of supermassive black holes found to date. It is also the pair with the smallest separation between two supermassive black holes found to date — observed to be just 1600 light-years apart in the sky.   The image on the left was taken with the MUSE instrument on ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile while the one on the right was taken with ESO’s VLT Survey Telescope.

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have revealed the closest pair of supermassive black holes to Earth ever observed. The two objects also have a much smaller separation than any other previously spotted pair of supermassive black holes and will eventually merge into one giant black hole.

Located in the galaxy NGC 7727 in the constellation Aquarius, the supermassive black hole pair is about 89 million light-years away from Earth. Although this may seem distant, it beats the previous record of 470 million light-years by quite some margin, making the newfound supermassive black hole pair the closest to us yet.

Supermassive black holes lurk at the centre of massive galaxies and when two such galaxies merge, the black holes end up on a collision course. The pair in NGC 7727 beat the record for the smallest separation between two supermassive black holes, as they are observed to be just 1600 light-years apart in the sky.

“It is the first time we find two supermassive black holes that are this close to each other, less than half the separation of the previous record holder,”

says Karina Voggel, an astronomer at the Strasbourg Observatory in France and lead author of the study published online today in Astronomy & Astrophysics.

“The small separation and velocity of the two black holes indicate that they will merge into one monster black hole, probably within the next 250 million years,”

adds co-author Holger Baumgardt, a professor at the University of Queensland, Australia. The merging of black holes like these could explain how the most massive black holes in the Universe come to be.

Voggel and her team were able to determine the masses of the two objects by looking at how the gravitational pull of the black holes influences the motion of the stars around them. The bigger black hole, located right at the core of NGC 7727, was found to have a mass almost 154 million times that of the Sun, while its companion is 6.3 million solar masses.

Just as people at a busy crossroad may accidentally bump into each other, so too can galaxies in the Universe! But in this case, the outcome is more dramatic than a small nudge. When two galaxies clash, they merge into each other, giving birth to a new, bigger one. One example is the NGC 7727 galaxy, shown in this image from ESO’s VLT Survey Telescope (VST) in Chile. Located 89 million light-years away from Earth in the constellation Aquarius, NGC 7727 is believed to be the result of a clash between two galaxies that occurred about one billion years ago. The consequences of this tremendous cosmic bump are still evident in the peculiar, irregular shape of NGC 7727 and the streams of stars in its outer regions.  The image was taken in visible light as part of the VST-ATLAS survey. The goal of the survey is to map a vast region of the Southern Sky — so large you could fit about 19,000 full moons in it! By studying the galaxies in this region, astronomers aim to shed new light on the nature of dark energy, the mysterious force permeating the Universe and causing its accelerating expansion.

It is the first time the masses have been measured in this way for a supermassive black hole pair. This feat was made possible thanks to the close proximity of the system to Earth and the detailed observations the team obtained at the Paranal Observatory in Chile using the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s VLT, an instrument Voggel learnt to work with during her time as a student at ESO. Measuring the masses with MUSE, and using additional data from the NASA/ESA Hubble Space Telescope, allowed the team to confirm that the objects in NGC 7727 were indeed supermassive black holes.

Astronomers suspected that the galaxy hosted the two black holes, but they had not been able to confirm their presence until now since we do not see large amounts of high-energy radiation coming from their immediate surroundings, which would otherwise give them away.

“Our finding implies that there might be many more of these relics of galaxy mergers out there and they may contain many hidden massive black holes that still wait to be found,” says Voggel. “It could increase the total number of supermassive black holes known in the local Universe by 30 percent.”

The search for similarly hidden supermassive black hole pairs is expected to make a great leap forward with ESO’s Extremely Large Telescope (ELT), set to start operating later this decade in Chile’s Atacama Desert.

“This detection of a supermassive black hole pair is just the beginning,” says co-author Steffen Mieske, an astronomer at ESO in Chile and Head of ESO Paranal Science Operations. “With the HARMONI instrument on the ELT we will be able to make detections like this considerably further than currently possible. ESO’s ELT will be integral to understanding these objects.”

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Amateur/Student Satellite, Education, Space Systems

Nanoracks to deploy FEES2 picosat from the ISS

Nanoracks and GP Advanced Projects (GPAP) will soon deploy a picosat a third the size of a standard CubeSat from the International Space Station.  GPAP refers to its picosat design as a 1/3U CubeSat (10cm x 10cm x 3cm). The first demo reached orbit in 2020 and was called the Flexible Experimental Embedded Satellite  or FEES.

FEES is a 1/3U Cubesat for in-orbit demonstration and validation of electronic components.

Cubesats systems were born in 1999 as a result of the cooperation between California Polytechnic State University and Stanford University, which defined the standards of this new satellite category. Typical Cubesats have a 10x10x10 cm dimension, 1U volume and are nominally in the nanosat or picosat satellite class.

These attributes being set, Cubesats allow affordable cost launch and different applications, since they lend themselves to educational, scientific and commercial purposes.

…

More than fifteen years later than the first cubesat prototype, we knew we could go even further. This vision led us to the development a 1/3U Cubesat, miniaturising the Cubesat technology in just 30% of former volume. FEES is the result of our commitment to this project.

Incredible partners like Politecnico di Milano, Brno University of Technology, CESI, LINKIT, Laser and Pandigital joined us in the program, giving birth to a 10x10x3cm satellite with a 300g mass which has been launched into orbit in October 2020.

Here is the announcement of the deployment of second FEES satellite (FEES2) into orbit, this time from the ISS:

Nanoracks to Deploy First-Ever 0.3U CubeSat from Space Station

NOVEMBER 23, 2021 – Torino, Italy – Nanoracks Europe is on track to set a new record as the company prepares to deploy the first-ever 0.3U CubeSat from the International Space Station (ISS). The satellite, named FEES2, was developed by the Italian company GP Advanced Projects and is approximately the thickness of a cherry. It will be one of the smallest trackable objects deployed directly from the Space Station.

FEES2 (Flexible Experimental Embedded Satellite-2) is a platform for demonstrating and validating CubeSat technology in orbit. The mission will test critical satellite components, such as GPS receivers and attitude control systems that have specifically been designed for miniaturized experiments.

GP Advanced Projects (GPAP) selected Nanoracks Europe for the integration services, launch brokerage, and deployment of FEES2 in June 2021 to reach orbit quickly and efficiently. Nanoracks’ proven business model provides flexible opportunities for its customers to demonstrate innovative technologies utilizing the ISS.

Guido Parissenti, CEO and co-founder of GPAP, remarked that

“The ISS has been a sort of booster for our company’s growth. Thanks to this deployment opportunity, which we contracted just five months ago, we will reach a major milestone towards the building of the first Italian nanosatellite constellation for IoT [Internet of Things], which is our long-term goal.”

The miniaturization of space technologies is a trend that allows for broader participation in space research and for CubeSat developers to make progress more rapidly. Companies like GP Advanced Projects that are seeking to deploy small satellites might have had difficulties reaching orbit in the past due to funding or launch accommodations. This mission demonstrates that such deployments are not only possible but that they can also be completed in a very short amount of time.

To approve FEES2 for deployment from the ISS, Nanoracks performed a feasibility study with NASA to verify the satellite’s trackability and quantify its deployment parameters. After careful evaluation, FEES2 was approved for integration into a Nanoracks CubeSat Deployer (NRCSD). The satellite is now integrated into an NRCSD with several other CubeSats and is manifested on the 24th SpaceX Commercial Resupply (SpX CRS-24) mission to the ISS, which is planned to launch in December 2021.

“We were excited that GP Advanced Projects entrusted Nanoracks to get the job done,”

said Adriana Aiello, Systems Engineer for Nanoracks Europe.

“Of course, we were going to make this happen for GP Advanced Projects – this is our specialty. Our customers’ needs challenge us to be innovators and disruptors, and we’re proud to bring a new customer and new technology to the Space Station.”

[Nanoracks Europe’s CEO, Veronica La Regina, said,]

“This is an absolutely exciting opportunity for Nanoracks Europe to make a difference in enabling wider access to space in our community,” […] . “Nanoracks’ passion for opening space access is one of our greatest assets, and this mission proves to be yet another example of the tenacity for making new things happen.”

Nanoracks offers a variety of satellite launch opportunities, including deployments from the International Space Station, the Northrop Grumman Cygnus spacecraft, the SpaceX Rideshare program, and from India’s PSLV. Learn more about Nanoracks’ satellite opportunities here.

About Nanoracks: Nanoracks, a Voyager Space Company, is the world’s leading commercial space services provider. Nanoracks owns and operates private hardware on the International Space Station and has launched over 1,300 research experiments, deployed over 300 small satellites, and owns and operates the Bishop Airlock on the ISS. Today, Nanoracks leverages over a decade of experience to develop new commercial space systems in direct response to customer needs. These space systems include converting commercial launch vehicle upper stages into functional secondary platforms, building new habitable space stations, supplying payload and crew airlock systems and services infrastructure, and more. Follow @Nanoracks on Twitter to learn more.

About GP Advanced Projects: GP Advanced Projects is an innovative SME active in both production and management of space projects. The company is developing PiCo, a picosatellite constellation dedicated to IoT data retrieval anywhere in the world. The first demonstrator satellite has been successfully deployed in March 2021.

In addition, thanks to its experience in project & innovation management, GP Advanced Projects enabled different non-space companies and institutions entering the space sector; the company is also actively engaged in scientific projects for both ESA and NASA.

For more information, visit https://www.gpadvancedprojects.com/

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