Февраль 2022 г.

Российская наука и мир (по материалам зарубежной электронной прессы)

CONTENTS / ОГЛАВЛЕНИЕ


• Russian space systems developing space-based solar power satellite
• Fifty-six years ago, the Luna 9 mission executed the first-ever soft landing on the Moon
• Plant "biofactories" produce proteins for potential COVID-19 vaccine
• Des scientifiques russes transforment les masques usagés... en composants de batteries
• Manchurian wapiti drowned in Baikal is helpful in understanding how chemical elements accumulate in animal organism
• Ural Federal University: Scientists found an evolutionary link in pain reactions in fish and humans
• Creation of a prosthetic joint with a coating that ensures faster bone integration
• What did medieval Russians do for fun? Ice skating - on bones
• Russia aims to rekindle moon program with lunar lander launch this July
• Russia considers establishing space tracking station at Svalbard
• Nornickel starts biodiversity study
• Physicists discover the chambers of secrets at the 16th century monastery in Pereslavl-Zalessky
• Tomsk State University: Biologists discovered Eranthis longistipitata as a potential remedy
• Record-breaking supernova is part of a new class of objects
• New finding in astronomy: black hole spins on its side

Специалисты холдинга «Российские космические системы» разработали проект солнечной космической электростанции. Она предназначена для энергоснабжения труднодоступных районов Земли, а также для плановой и аварийной подзарядки космических аппаратов. Электростанция состоит из беспилотного космического корабля, аккумулирующего солнечную энергию и передающего ее по лазерному каналу в принимающий модуль, после чего энергия преобразуется в электрическую и передается пользователям.

The Russian Space Systems holding (part of the Roscosmos State Corporation) has developed a project for a promising solar space power plant (SCES). It is designed to supply power to hard-to-reach - island, mountainous and northern - regions of the Earth, as well as for scheduled and emergency recharging of spacecraft.
How does a space solar station differ from those familiar to everyone on the ground? In the Earth’s atmosphere, the sun’s rays are scattered and partially lose their energy efficiency. In outer space, the efficiency of using solar energy is ten times higher. RCS scientists proposed to convert it into a laser beam and transmit it to Earth with minimal energy loss.
According to the project, the SCES consists of two segments. The first, transmitting module is an unmanned spacecraft with an area of 70 m2 which accumulates the energy of the Sun and transmits it to the Earth. The second receiving module is a system of ground-based rectennas (mobile antennas) with batteries that receive solar energy from the spacecraft via a laser channel, convert it into electricity and distribute it to consumers. The advantages of laser energy transfer are fast translation (from a nanosecond) and extremely low beam divergence. The transmitting module can also serve as an orbital charging station - to transfer the accumulated energy to space satellites for operational recharging.
The station operates according to the scheme of separate energy storage: the collector receives solar radiation, and it is distributed in two directions. About 5% goes to the supply battery that powers the SCES itself. The remaining 95% are transferred to a storage battery designed to transmit energy to Earth. There is also a buffer for the accumulation of solar energy, which is activated when the supply and storage batteries are overfilled. At any time, this buffer electrical energy can be directed through a cyclotron converter to a ground-based rectenna with a laser.
The development was initiated in 2012 by Maria Barkova, a research engineer at the Advanced Equipment Development Department of the RKS.
"The problem of energy storage in orbit arose long ago. Back in the 1920s, Valentin Glushko proposed to build a helio-rocket plane, a spacecraft powered by solar energy. The basic concept of a solar space power plant was proposed by Peter Glaser in the 1960s. Today, this topic has become especially relevant: on the one hand, there is a search for safe and environmentally friendly energy sources that are not related to fossil resources - oil, gas, coal, on the other hand, there is a need to develop hard-to-reach territories for their development and inclusion in the economic and infrastructure system".
The project involves the creation of low power SCES (up to 100 kW per broadcast). Energy accumulates for quite a long time: 600 MW will have to wait a month and a half - or create a large constellation of spacecraft, and this is expensive.
"SKES will find it difficult to compete with traditional ways of generating energy: thermal power plants, hydroelectric power plants, nuclear power plants," said Maria Barkova. "But it can be useful in remote areas of Russia, where the use of traditional methods of generating energy will be fraught with the difficulties of building and delivering fuel."
It is assumed that space power plants will be in sun-synchronous orbits with an inclination of 82°, 90° and 98°. Accurate targeting of the laser beam to mobile ground-based rectennas will be provided by a synchronizing software package.
The developers have prepared a feasibility study for the creation of SCES. According to their estimates, the pilot station, consisting of one spacecraft and one rectenna, will pay off within 20 years, and the energy received at it in hard-to-reach areas will cost 2-6 rubles per 1 kWh. Regional authorities are considered as a potential customer at the initial stage.
The RKS station has competitors. For example, China is developing a project for a large station in geostationary orbit. But Russian scientists believe that collecting it in space would be too expensive. The Japanese propose to create a SCES in a low-stationary orbit, which will transmit energy to the Earth via microwave waves. The RCC says that this will be ineffective: the microwave has a greater beam divergence than the laser, which is fraught with large energy losses.

3 февраля 1966 года впервые в истории советский аппарат совершил мягкую посадку на Луну. Автоматическая станция «Луна-9» проработала три дня, передав на Землю различные данные, в том числе панорамные изображения лунной поверхности в высоком разрешении.

The Luna 9 mission was launched from the Baikonur Cosmodrome on a Molniya-M rocket, which was derived from an intercontinental ballistic missile, on January 31, 1966. The first three stages inserted Luna 9 into low Earth orbit, with the fourth stage increasing the altitude to achieve a highly elliptical geocentric orbit, which carried it all the way to the Moon. At an altitude of 233,000 kilometres from the surface, the spacecraft executed a 48 second burn for a mid-course correction manoeuvre to direct it to the Oceanus Procellarum, or the Ocean of Storms. Nitrogen jets kept the spacecraft spinning at 0.67 rpm. At an altitude of 8,300 kilometres, the spacecraft oriented itself for the firing of the retro thrusters, halting its spinning motion. At an altitude of 75 kilometres, the spacecraft was traveling at a velocity of 2.6 km/s, when the airbags were inflated, the side modules and nitrogen tanks that inflated the airbags were jettisoned, and the retro thrusters began firing. The two shock absorbing airbags inflated around the spacecraft, maintaining it in a pressure of 1 atmosphere. The main engine executed a 48 second burn, From an altitude of 74.885 kilometres to 250 meters. At this point the main engine was shut off, and the four outrigger motors took over, decelerating the spacecraft to a velocity of a few metres per second.
At an altitude of 5 meters, a long boom sensor made contact with the surface, shutting down the engines and ejecting the spherical landing capsule, still enclosed within the airbags impacted the surface at 22 km/h bounced on the surface a few times before coming to rest. The technically sophisticated landing was perfectly executed, was the first soft landing on the surface of another celestial body, and the first soft landing on the Moon. The Soviets had accomplished another first in the space race, and had proven that a lander on the Moon would not simply sink into the dust. About four minutes after the landing, the airbags split open, and the four petals forming the shell of the spacecraft split open. Although there were some solar cells to slowly replenish the energy of the battery, the battery was the primary source of power for the spacecraft. The spring-controlled communication antennas were deployed and the spacecraft started beaming back telemetry data. Seven hours later, after allowing the Sun to rise sufficiently in the horizon to provide ample light, the TV camera on board started beaming back the first images from the lunar surface back to the Earth, in the form of fm waves using the Radiofax standard.
According to the BBC, the Russian scientists deliberately used this standard so that they could get high resolution images from the astronomers at the Jodrell Bank Observatory in England without having to ask for them, or to prevent the Soviet Union from monopolising the science findings. The Daily Express published the images, while the Soviet Union never released them officially. A total of 27 images were beamed back, including three panoramas. Radiation data was also sent back, showing readings of 30 millirads a day. Three days after the first human probe executed a soft landing on the Moon, the batteries depleted and the spacecraft stopped transmitting data. NASA's Lunar Reconnaissance Orbiter which has been observing the Moon since 2009, has detected a number of previous spacecraft that landed on the surface, including all six Apollo landing sites. The spacecraft is still on the lookout for the landing site of the historic Luna 9. Sadly, the tiny size of the spacecraft makes it hard to find.

В ФИЦ «Фундаментальные основы биотехнологии» РАН предложили синтезировать белки-антигены для вакцины от COVID-19 в листьях табака, перенося вирусный вектор в растительные клетки с помощью бактерий Agrobacterium tumefaciens.

Russian scientists demonstrated that proteins, which could be used to develop intranasal recombinant mucosal vaccines against COVID-19, can be produced in tobacco plants.
COVID-19 is caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). SARS-CoV-2 replicates by infecting human cells via the interaction of the receptor-binding domain (RBD) on the viral Spike (S) protein with a human receptor, angiotensin-converting enzyme 2 (ACE2). Without the S protein, and particularly the RBD, SARS-CoV-2 cannot infect cells, and thus these sites have become the focus of vaccine development efforts in the pandemic.
RBD-based vaccines and other vaccines of the same type train the immune system to recognise SARS-CoV-2; however, many vaccine types require adjuvants to enhance the immune response. One adjuvant that has been successfully used in vaccines against influenza A is to attach an antigen to bacterial flagellin (Flg) protein, which stimulates the TLR5 receptor to promote a response.
In a new study, scientists from the Research Center of Biotechnology RAS, Russia, demonstrated that a recombinant protein comprising the S RBD and Flg could be produced in plant cells.
"Biotechnology allows synthesising vaccine antigen proteins in animal cells, bacteria, yeast, plants and other organisms. We put the sequence from the SARS-CoV-2 protein and the flagellin sequence of the bacterium Salmonella typhimurium into the pEff viral vector and infected the plant Nicotiana benthamiana, which belongs to the genus Tobacco. pEff causes plant cells to produce the proteins we need in large quantities. Using this vector, the authors of previous studies were able to obtain up to 1mg of a green fluorescent protein from each gram of fresh leaves in just a few days," explained Eugenia Mardanova, one of the authors of the paper and the senior researcher at the Laboratory of Molecular Cloning at the Research Center of Biotechnology RAS.
Plants were chosen for these experiments because producing proteins in this way does not require sophisticated equipment and can be easily scaled up. Additionally, since plant pathogens typically do not impact humans, the product may be safer than in other types of cells. However, transgenic plants have disadvantages as producers: they typically yield low levels of the desired proteins, and it may take several months to obtain transgenic plants. Moreover, isolation of the final product from plant cells and its purification is quite expensive. But, by transiently infecting the plant using the pEff vector, plants can produce up to 5mg of vector-encoded protein from each gram of leaf within a week.
Biotechnologists chose an RBD fragment with 319 to 524 amino acids and attached Flg derived from Salmonella to it, resulting in a recombinant protein Flg-RBD. This construct was inserted into the pEff vector, which was then absorbed by the bacteria Agrobacterium tumefaciens. These microorganisms transferred the viral vector into the plant cells. Flg with no RBD was used as a control.
After four days, when the required amount of protein was reached, the researchers harvested the leaves of the plants. The plant "biofactories" were able to produce 110-140 micrograms of recombinant protein per gram of fresh leaf biomass (μg/g). Following purification with metal affinity chromatography under denaturing conditions, the final yield of protein was 100 μg/g. The control yielded 300 μg/g of Flg after purification.
"Our studies showed that using the pEff vector we can make plants producing recombinant protein we need - up to 100 micrograms per gram of biomass. This protein could be the basis of new vaccines against coronavirus infection that can be applied as nasal drops. Due to the adjuvant properties of flagellin, such vaccines should induce both a local and systemic immune response. We believe that this approach will make the production of drugs cheaper, and the vaccinations themselves will become more convenient, faster, and easier," concluded Nikolay Ravin, Head of the Laboratory of Molecular Cloning of the Institute of the Research Center of Biotechnology RAS.
The research was published in Plants.

Ученые из НИТУ «МИСиС» совместно с коллегами из США и Мексики предложили перерабатывать использованные медицинские маски и блистерные упаковки от лекарств в недорогие аккумуляторы для бытовой техники. Маски дезинфицируют, пропитывают «чернилами» из графена, прессуют и нагревают до 140°С, в результате чего образуются маленькие гранулы, которые и будут служить электродами. Изоляторы между электродами также делается из масок, а защитная оболочка - из блистеров.

Si les masques sont de précieux alliés face à la pandémie, ils n’aident pas à réduire la pollution liée au plastique sur la planète. Le recyclage de masques, quand il est possible (la start-up française Plaxtil s'y essaie) s'opère à toute petite échelle. Alors que l’OMS s’inquiète de la montagne de déchets médicaux liés au Covid-19, une équipe de chercheurs russes de l’Université nationale des sciences et de la technologie "MISIS", basée à Moscou, a mis au point une solution pour recycler les masques… en composants de batteries ! Et les résultats sont plutôt étonnants.
Des masques et des emballages de médicaments
« Nous avons étudié les performances électrochimiques de supercondensateurs à l'état solide fabriqués à partir de déchets de masques chirurgicaux et de blisters recyclés à partir d'emballages de paracétamol », expliquent les chercheurs dans leur étude. En langage commun, cela signifie qu’ils ont pu reconstituer les éléments cruciaux de la batterie comme les électrodes avec des masques.
Pour y arriver, ils ont tout d’abord collecté puis désinfecté les masques en utilisant des ultrasons puis en les plongeant dans une encre à base de graphène. Une fois lavés, les masques sont compactés et chauffés à une température de 140 °C. A l’issue de ce procédé, les équipes obtiennent des petits granulés : ce sont ces petites billes qui serviront d’électrodes dans la future batterie. Ces électrodes sont ensuite séparées par un isolant, également réalisé à base de masques.
98 wattheures/kg
Le miracle du recyclage des déchets ne s’arrête pas aux masques ; des emballages de médicaments ont aussi été utilisés pour fabriquer un élément indispensable à la batterie : l’électrolyte. Au final, l’équipe a réussi à construire une batterie en atteignant une densité énergétique de 98 wattheure/kg. Une performance insolente pour cette batterie à faible coût lorsque l’on sait qu’une batterie de Tesla Model 3 affiche 260 Wh/kg.
Les scientifiques ont même amélioré leur découverte « en ajoutant des nanoparticules de pérovskite inorganique de type oxyde de CaCo aux électrodes issues des masques », précise le communiqué de l’université. Cela a permis d’augmenter la capacité énergétique des batteries à 208 wattheures/kg.
Il aura fallu du temps aux scientifiques avant d’arriver à un résultat conclusif. Précédemment, ces derniers avaient tenté d'utiliser divers matériaux naturels poreux tous aussi improbables pour fabriquer les électrodes comme des coquilles de noix de coco, des balles de riz et même des pneus de voiture usagés. Cependant, ces matériaux nécessitaient toujours d’être chauffés à haute température dans des fours spéciaux : les masques se sont avérés être un matériau plus facile et moins cher à traiter.
Maintenant que l’équipe scientifique sait comment débarrasser la planète de nos masques usagés, elle prévoit d'appliquer sa technologie à la production de batteries pour voitures électriques et aux centrales solaires.

Изюбрь, утонувший в декабре в Байкале, поможет ученым Томского политехнического университета понять, как геохимические элементы распределяются в живых организмах в зависимости от особенностей горных ландшафтов. Исследователи надеются, что полученные данные помогут разработать рекомендации по профилактике эндемических заболеваний.

Researchers of Tomsk Polytechnic University have dissected a carcass of a Manchurian wapiti drowned near Olkhon Island of Lake Baikal in December. The collected biomaterials will be helpful in understanding how geochemical elements depending on characteristics of mountain landscapes are distributed in living organisms. In the long run, besides fundamental conclusions, the researchers hope that will be able to form guidelines for the prevention of endemic diseases.
The interdisciplinary project entitled Impact of Lithological and Geochemical Characteristics of Mountain Landscapes of Siberia and the Far East on Formation of Elemental Composition of Mammalian Organism was supported by a grant from the Russian Science Foundation and will last four years (2020-2024). The research works are being conducted by the TPU researchers jointly with scientists from the Pacific Geographical Institute of the Far Eastern Branch of the Russian Academy of Sciences.
The TPU researchers carried out the research of the territories of Primorye and the Gornyi Altai. This year, they have already started the research of Baikalia, Transbaikalia and Buryatia. The territories for the project were chosen due to their specific chemical composition of rocks. During their expeditions, the TPU researchers collect samples of rocks, water, soils, vegetation and biomaterials.
"The case that occurred on Olkhon Island can be called unique. It is essential for the research of fodder impact on the formation of the elemental composition of a mammalian organism.
"The case that occurred on Olkhon Island can be called unique. It is essential for the research of fodder impact on the formation of the elemental composition of a mammalian organism.
Of course, we cannot pick up animals in protected areas. We cooperate with hunting sectors neighboring such territories or select objects for a biopsy in private households. Frequently, it is season work. A seasonal epizootic of animals can be seen on some territories during a winter. Therefore, we can collect bone material and wool samples. Therefore, it was a quite rare opportunity when as a result of an accident we were able to collect the samples of a brain, organs, bone material belonged to an animal from a nature reserve," says Natalya Baranoskaya, Professor of the TPU Division for Geology and Head of the project.
According to her, the Manchurian wapiti was tracked down in the water by wolves. During six hours, staff of Pribaikalsky National Park, a policeman and locals tried to rescue the animal. Due to the thin ice, it was impossible to come closer to the Manchurian wapiti. By the moment rescuers finally pull the animal ashore, it had been dead. The animal remains, which were not useful to the researchers for further examination, were delivered to countries of golden eagles for supplementary feeding.
"We prepare the collected samples for examination and carry out a wide range of analyses. These analyses are inductively coupled plasma mass spectrometry to determine chemical composition, instrumental neutron activation analysis conducted at the TPU Nuclear Research Reactor and scanning electron microscopy. Factually, these are analyses for all chemical elements of the periodic table. We have already obtained rather interesting data on the concentration of chemical elements in the brain and spinal cord of the animals on territories with different geochemical conditions. As a result of the four-year research work, we must identify the significance of every organic component and metal-organic complex inside the animal organism, which mostly determine its life. The solution of such a fundamental problem will assist in the prevention of human and animals' diseases," explains Natalya Baranovskaya.

Российские и бразильские ученые исследовали переносимость боли и страха в зависимости от пола на примере аквариумных рыбок зебраданио (Danio rerio). Рыбки обладают 70-процентным генетическим сходством с человеком, родственной физиологией, нейроанатомией и нейрохимией, что делает их подходящим модельным объектом для биомедицинских исследований. У самок оказалась более выраженная и продолжительная реакция на боль, пугались же представители обоего пола совершенно одинаково. В дальнейшем результаты исследования могут быть использованы при разработке препаратов для снятия боли с учетом пола пациента.

A group of scientists from universities in Russia and Brazil investigated the effect of gender on the tolerance of pain and fear in laboratory zebrafish. The research contributes to the development of medications that alleviate pain by taking into account the gender of the patient.
So far, the relationship between pain and gender in zebradanio has been poorly studied, although this freshwater fish species has a large, 70% genetic similarity to humans, related physiology, neuroanatomy and neurochemistry. Thus, zebradanios are a good model for studying how the brain responds to pain or fear. The researchers’ paper describing the experiments and their results is published in the journal Neuroscience Letters.
In the work, the "collective" of male and female zebradanios was divided into control and experimental groups. For the first experiment, to determine the body’s response to pain, researchers selected 12 males and females each. They were injected with a solution and run in a test tank. For a few minutes recorded changes in their behavior compared to the control, untreated group of individuals. Both males and females involved in the experiment reacted to pain by climbing up to the upper level of the aquarium less often, more often to the bottom, which was safer for them, slowed down their movement in the water, froze in torpor. At the same time, the behavior of females was more pronounced, and their reactions to stress by pain were more frequent and longer lasting.
In the second experiment, scientists investigated the behavioral responses of zebradanio to a source of fear. For this purpose, nine males and females each were placed for a few minutes in a vessel with a substance pheromone of fear, which causes severe anxiety in fish. In this experiment, behavioral changes in the individuals were equally strong and independent of their gender. As in the first experiment, the fish slowed down, stopped, and froze more frequently than the individuals in the control group, and also swam up to the water surface less frequently.
"It is known, for example, that female rodents are more sensitive to pain than males, and the same can generally be said about female reactions to pain. Therefore, our experiments indicate that gender differences in reactions to pain have persisted in the course of evolution, from fish to mammals. This means that animals such as zebradanio, which are fast breeding, unpretentious, inexpensive to keep and therefore so convenient for biomedical experiments, can be used for search and creation of new drugs capable of reducing pain sensitivity with regard to sex differences", commented Alan Kaluev, head of research, leading researcher of Ural Federal University, member of European Academy, professor of Saint Petersburg State University and Scientific and Technical University.
The conducted scientific work fully corresponds to the concept of the state Strategy for Scientific and Technological Development of Russia, one of the priorities of which is the promotion of personalized medicine. On the Russian side, the scientists’ research was supported by the Russian Science Foundation, the Russian Academician A.M. Granov Research Center for Radiology and Surgical Technologies, and the Sirius Scientific and Technological University.

Российские исследователи создали протез тазобедренного сустава со специальным полимерным пленочным покрытием, которое ускоряет процесс сращивания с костью и снижает риск послеоперационных инфекций.

Russian scientists have developed a hip prosthesis with a coating that provides faster bone-to-implant integration while reducing the risk of post-surgery infections.
The new prosthesis was developed by a joint team of the Skolkovo Institute of Science and Technology (Skoltech), the Samara State Medical University (SSMU) and the Tios bioengineering company, all of them members of the SSMU-based NTI Center for Bionic Engineering in Medicine.
"The team has designed an artificial hip joint with a polymer film coating that degrades in the body as soon as it releases the drug, while ensuring manifold increase in antimicrobial efficiency and better osseointegration," the NTI Platform spokesperson explained.
The polymer coating shaped like a medication blister pack is made of polylactic acid and other biodegradable materials that facilitate drug release. The coating can be "tuned" for slow drug release or fast ejection by ultrasound, where necessary. The tests showed that the coating also helps prevent scarring around the implant, the researchers noted.
The team performed the first-ever surgery on a patient with bone chondrosarcoma and installed a new type of hip prosthesis with an antibiotic-releasing film coating. The operation took place at the Applied Research Center for Bone, Soft Tissue and Skin Tumors at the Moscow Oncology Hospital No 62.
The authors note that their high-density coating is easily filled with the drug and, therefore, is perfectly suitable for personalized medicine.

Изучение костей крупных домашних животных, обнаруженных при раскопках в Великом Новгороде в археологических слоях XI-XV веков, показало, что некоторые из них могли использоваться в качестве коньков. Костяные коньки существовали в странах Северной Европы и Скандинавии и, как оказывается, были популярны также среди древних новогородцев.

As the first flakes of snow cover the land, and as the lakes and rivers freeze, Russians from rug-rats to full-grown go outside to enjoy their favorite winter pastime: ice skating. They have done so for generations, and now a new study shows how they made their skates during the Middle Ages in ancient Novgorod: from the bones of household animals such as sheep and horses, which thusly continued to serve for transportation after death.
Moreover, however, while skating was a key mode of travel throughout much of ancient far-northern Eurasia, in medieval Russia skating was done for fun, an archaeologist suggests. In a new article published in the journal of Russian Archaeology, Oleg Oleynikov from the Institute of Archaeology of the Russian Academy of Sciences describes his study of animal bones unearthed at the site of Veliky Novgorod. He concluded that certain long bones had to have been used as ice skates. Using animal bones for skates was done in other northern European and Scandinavian countries and now, his research shows that this tradition had reached the eastern territories and was popular among the Old Russians in Velikiy Novgorod.
Founded by a Viking
The city’s story begins somewhere around 860 C.E., according to medieval Russian chronicles written from the 11th century onward. They mention Velikiy Novgorod as a major station on an important trade route, known as the "Varangian to the Greek route", which connected the Scandinavian trading centers with the Byzantine empire.
The Greek Road crossed the Baltics, ran along the rivers of modern-day western Russia, reached Velikiy Novgorod, and from there continued south along the Dnieper, through the territories of the Kyivan Rus, and extending to the Black Sea and the territories of the Eastern Roman Empire.
According to the primary chronicle written in the 12th century, Velikiy Novgorod was founded by Rurik of Ladoga, a Varangian chieftain of the Rus. He was invited to rule the area and later became the father of the Rurik dynasty that ruled Kyivan Rus. Rurik the Varangian was a "Viking". The term Viking was a term used by the Anglo-Saxons that meant pirates; and was given to the sailors and raiders coming from Scandinavia, conquering, settling, and exploring other countries. They were also known as the Northmen, Danes, the Varangian, or the Rus. They were expert navigators and sailors, sailing the rivers on their longships, called Drakkar, which were considered their major technological achievement and the key to their success. The Byzantines and the Slavs called them the Varangian and some also served the emperor as mercenaries, known as "The Varangian guard". They were also known as "the Rus", which most probably meant rowers, and the consensus is that they arrived from Sweden. They established the Kievan Rus state in the 9th century, a coalition of East Slavic, Finnish and Baltic tribes with whom the people from Sweden have merged and assimilated.
Kievan Rus encompasses the areas of modern-day Ukraine, Belarus, and west Russia, which derived their name from the Rus. Archaeological excavations at Novgorod do reveal a medieval presence at the site, but only a century later than suggested by the chronicles. However, written sources from the west and other archaeological finds indicate there might have been an earlier settlement in the area right next door, known as Rurikovo Gorodische. This site is known from Norse sagas as the settlement of Holmgard, and it lies just 2 kilometers south of Veliky Novgorod. It is possible that over time, Holmgard and Velikiy Novgorod merged in the historical memory.
In any case, come the Middle Ages, Novgorod had become the second most important city within Kievan Rus. It later established the medieval Russian state, the Novgorod Republic, encompassing lands from the Gulf of Finland to the Ural mountains. Here culture and literature thrived, giving birth to such manuscripts as the Novgorod first chronicle, one of Old Russia's ancient texts. The city retained its importance throughout the history of Russia. It is considered to be the cradle of modern Russia and has attained world heritage status, protected by UNESCO.
For over 80 years, extensive excavations conducted in Novgorod have been unearthing amazing finds from the medieval city, such as the famous birch bark manuscripts written in the Ancient Novgorod dialect, the Novgorod codex; as well as residential, administrative, and religious buildings, shedding light on the daily life of the Novgorodians. The current expedition also revealed a plethora of finds. But for now, let us concentrate on a specific find: bones used by the Novgorodians to craft skates.
When the horse passes on
In his latest study, Oleg Oleynikov examined a collection of tubular bones from large household animals whose remains were found in archaeological layers from the 11th to the 15th centuries. Based on experimental archaeological, ethnography, and comparison with similar objects found in neighboring northern countries, he concluded they had been used as skates.
The medieval bone skates were moderate-sized skids, made from horse and large cattle front and hinged metapodials, cut in their epiphyseal ends, with the plantar side of the shaft smoothed out to serve as the sliding surface of the skate. The ends were sometimes tapered to create a raised nasal part, helping the skate slide better on the icy surface.
In fact bone skates seem to have been used throughout ancient far-northern Eurasia. The earliest scientific find in Russia of these artifacts was made a century ago, at medieval Old Ladoga, another key port city in Old Russia along the route to Greece, as of the 8th and 9th centuries, predating even Novgorod. (The skates were found in layers from the 10th and 11th century however.)
About 190 km northeast of Novgorod, Ladoga was the first city to be ruled by Rurik before he moved to Novgorod. Bone skates have also been found in places such as York in England, Birka in Sweden, various sites in central Europe, Iceland, Ukraine, and even Kazahstan and the Black Sea, some of which go back to the Bronze and Iron Ages. Yet the first mention of "bone skates" was in a 12th-century C.E. manuscript written by an English monk named William Fitzstephen. In his biography of Thomas Becket, aka Saint Thomas of Canterbury, "The Life of St. Thomas," Fitzstephen provides a colorful description of the City of London in the 12th century. There he describes bone skating as one of the local pastimes.
"Furthermore let us consider also the sports of the city, since it is not meet that a city should only be useful and sober, unless it also be pleasant and merry," Fitzstephen wrote. "When the great marsh that washes the Northern walls of the city is frozen, dense throngs of youths go forth to disport themselves upon the Ice. Some gathering speed by a run, glide along, with feet set well apart, over a vast space of Ice." Some fashioned seats out of ice and were dragged along, he added: "Sometimes they slip owing to the greatness of their speed and fall, every one of them upon their faces."
Fitzstephen goes on to describe the skilled ones who "who fit to their feet the shin-bones of beasts, lashing them beneath their ankles, and with iron-shod poles in their hands they strike ever and anon against the Ice and are borne along swift as a bird in flight or a bolt shot from mangonel." And kids will be kids - they would play a medieval version of ice chicken, skating at speed to one another with the object of hitting one another with poles. Yes, injuries would ensue. "Often he that falls breaks arm or shin, if he fall upon it. But youth is an age greedy of renown, yearning for victory, and exercises itself in mimic battles that it may bear itself more boldly in true combats," Fitzstephen concludes (from Gourde L.T. 1943, An Annotated Translation of the Life of St. Thomas Becket by William Fitzstephen).
Whee!
Excavation in Novgorod from 2008 to 2019 yielded over 50 such skates. Most were made from horse metapodials. The length of the skates varied between 17 to 39 cm, dominated by skids between 21 to 30 cm in length. It can be assumed that the smaller skids, 17-20 cm, were used by kids, whereas the bigger ones by adults, as Oleynikov noted.
Making the skates was a simple task: even a child could do it, and didn’t require any special tools. However, some may have been made by professional skate artisans, although no such workshops were found in Novgorod. In Scandinavia, where skates were used more widely, one such workshop was found in Norway.
There were two types of bone skates. One had holes on the epiphysial part to tie the skate to the shoes using laces binding to the toes and heels. The second type had no holes, suggesting they were used in a different manner.
Unlike their modern counterparts skaters, the medieval skaters would push themselves using one or two poles with pointed tips. Their speed would be affected by arm strength and the skating surface. Here you can see how Rosalin, a medieval reenactor from the Netherlands, is skating with the bone skates, called Glissen in Dutch, using two poles. She also tried gliding with one pole but found it trickier and not as easy as the two. She noted how the icy surface affected the gliding experience.
Given that they were harder to use, Oleynikov suggests that skates unattached to the shoe may have been used like a scooter, with one leg pushing the glider and the other placed on the bone. Or, Oleynikov says, they may have been used by towing, with the skater holding onto a rope and pulled by someone else.
Medieval manuscripts and art provide us with a further understanding of their use and popularity. Such as the works of the Swedish historian and geographer Magnus Olaus from the 16th century, the Skater by Rembrant from c. 1639, and a depiction of a demon bird with skates on an icy lake in the left panel from the work of Hieronymus Bosch, the temptation of St. Anthony from 1500.
Clearly skates were an important means of transportation for hunters and fishermen in other parts of Europe, unlike in Russia, where they were apparently used mainly for fun. This may have to do with the Russian climate. In winter, because of the rapid onset of snow and its quick build-up, ice surfaces suitable for skating are available only for short periods. Skating is simply not a useful form of transportation in Russia. But it can be loads of fun.

В июле этого года с космодрома Восточный предполагается запуск автоматической межпланетной станции «Луна-25» (миссия «Луна-24» состоялась в 1976 г.), которая должна возобновить российскую программу изучения спутника Земли. У «Луны-25» три основные задачи: отработка технологии мягкой посадки; разведка природных ресурсов, в том числе водных, в районе южного полюса Луны; исследование воздействия космических лучей и электромагнитного излучения на поверхность Луны.

Russia is ready to reactivate its moon exploration agenda, a former Soviet Union enterprise that ended decades ago. The last in the series of pioneering Soviet robotic lunar missions was Luna 24, which sent about 6 ounces (170 grams) of moon material back to Earth in 1976.
Russia's planned Luna 25 mission is set to kick-start a sequence of lunar outings that also involves Europe and China. For example, Russia intends to collaborate with China on the International Lunar Research Station, which is targeted to be operational by 2035.
Russia's rekindling of its lunar exploration objectives would clearly be bolstered by the success of Luna 25, a lander mission scheduled to launch this July. But how Russia and China's moon exploration plans will truly jell, and how this partnership might influence NASA's lunar "rebooting" via its Artemis program, are not clear.
Primary destination
Luna 25 will launch atop a Soyuz-2.1b rocket with a Fregat upper stage from the Vostochny spaceport in the Russian Far East. The probe's primary destination is the moon's south polar region - specifically, a spot north of Boguslavsky Crater. (An area southwest of Manzini Crater is a backup locale).
Russia's NPO Lavochkin, a spacecraft building firm, constructed the lander, which is billed as a pathfinder probe for testing soft-touchdown technologies in the moon's circumpolar region and conducting contact studies of the lunar south pole.
Pavel Kazmerchuk, Luna 25 chief designer at Lavochkin, has stated that all scientific instruments have been installed on the probe. Electro-radio engineering testing is currently underway, to be completed in March. Development of onboard software for the craft is scheduled to be finished in April. But Luna 25's road to the moon hasn't been an easy trek. Problems found during testing of the nearly 2-ton spacecraft spurred slips from an October 2021 liftoff to May 2022, and now the craft is being readied for a "preferred" July 23 departure.
"In 2021, the Luna 25 spacecraft has been fully assembled; a large amount of ground experimental testing has been performed. The spacecraft is to be launched from the Vostochny Cosmodrome within the launch window of May 25 to October 19, 2022, but we are aiming at July," Dmitry Rogozin, director general of Roscosmos, Russia's federal space agency, said in a statement last month.
Main tasks
Luna 25 is designed to operate on the surface of the moon for at least one year, making use of a suite of sensors to study the lunar topside and dust and particles in the moon's wisp-thin atmosphere, or exosphere.
According to Lavochkin, Luna 25 has three main tasks: develop soft-landing technology; study the internal structure and exploration of natural resources, including water, in the circumpolar region of the moon; and investigate the effects of cosmic rays and electromagnetic radiation on the surface of the moon. The lander carries eight Russian instruments, including a robotic arm to scoop up lunar regolith, and one developed by the European Space Agency (ESA) - a camera called Pilot-D, a demonstrator terrain relative navigation system.
Talent and experience
Eagerly awaiting the Luna 25 mission is James Head, a geoscientist in the Department of Earth, Environmental and Planetary Sciences at Brown University in Rhode Island.
"It is really great to anticipate the launch, landing and operations of Luna 25 in the south polar region of the moon later this year, and see Russian scientists and engineers bring their huge array of talent and experience into the active arena of lunar exploration," Head told Space.com.
"It will be many years before other countries will be able to duplicate the decades of groundbreaking robotic lunar exploration accomplished by our Russian colleagues over 40 years ago, with robotic lunar rovers and three sample-return missions," Head said.
Follow-on missions
According to ESA, the Luna 26 orbiter is scheduled to launch two years after Luna 25. Luna 26 will perform remote scientific measurements and serve as a possible communications relay for the next lander mission. It will transmit data back to ground stations on Earth, including ESA's ground station network.
The Luna 27 lander will launch one year after Luna 26 and will be larger than its predecessor, Luna 25. It will fly to a challenging landing site closer to the lunar south pole using the European Pilot technology as its main navigation system. Luna 27 will deploy the ESA-provided Prospect drill that will search for water ice and other compounds under the lunar terrain.
Currently, NPO Lavochkin is blueprinting a Luna 28 project for the delivery of lunar soil from the south polar region, an effort that is also designed to further subsequent expeditions to deploy a lunar base.
Roadmap for the moon
Last year, Rogozin and Zhang Kejian, the chief of the Chinese National Space Administration (CNSA), signed a memorandum of cooperation to begin orchestrating an International Scientific Lunar Station. An early roadmap for the moon outpost calls for a complex of experimental research facilities - on the lunar surface and/or in lunar orbit - to conduct tasks that make possible a long-term human presence on the moon.
China launched the research station project together with Russia, also initiating the Sino-Russian Joint Data Center for Lunar and Deep-space Exploration. China is working with Russia to coordinate its 2024 Chang'e 7 lunar polar exploration mission with Russia's Luna 26 orbiter mission.
Competitive game?
It's good news that the moon is getting more attention, said Clive Neal, professor in the Department of Civil Engineering & Geological Sciences at the University of Notre Dame in Indiana. Like Head, Neal is an authority on lunar science and exploration. Neal sees encouraging signs that a robust economy will develop in Earth-moon space - an economy that could be a template for doing similar things elsewhere in the solar system. But he also raised a number of concerns.
"The trouble we've got when looking at Russia and China - it appears to be a competitive game that is being played," Neal told Space.com. "I hope this is going to be a cooperative effort rather than something competitive in nature."
That said, Neal would like to see definitive plans flowing from NASA regarding a moon station. The American agency has stated that it aims to build a research outpost on the moon via its Artemis program, but details remain scarce at the moment.
"NASA needs to get serious about its base camp plans, because I don't think it is right now," Neal said. "There's a lot of bluster about sustained human presence on the moon, but what does that mean? It doesn't mean permanent."
Get serious about the moon
Neal said that he is "cautiously optimistic" that 2022 will be a great year for lunar exploration. Part of the optimism stems from the plans of American companies to deliver science and technology to the lunar surface through NASA's Commercial Lunar Payload Services initiative.
"They are now cutting metal. They've got payloads. They've got contracts. And they've got to deliver," Neal said. "I hope NASA will seize this opportunity as something to build into bigger and better things."
But Neal added that the U.S. space agency "needs to get serious about the moon … and Congress needs to provide the funding for NASA to get serious."
Lacking today is a resource prospecting campaign, one that is international in character, Neal said. "If you don't do the grunt work and the prospecting, you are never going to know if lunar resources can be utilized to do what some say they are going to be used to do."
Moon-exploration planners also need to define and implement a resource-prospecting campaign, Neal added. It remains unknown how such a campaign will operate and who will coordinate it.
"If NASA had an Artemis program office, perhaps that would be a good place for it. I'm hoping you're getting my sense of frustration," Neal said.
Neal said that he wishes good luck to China, Russia, NASA and all the American commercial groups in their moon endeavors. "If we all banded together to do this for the good of all humankind, then I think we'd be in good shape," he concluded.

Госкорпорация «Роскосмос» намерена разместить на архипелаге Шпицберген станции мониторинга космического мусора на околоземной орбите.

The Norwegian Arctic archipelago of Svalbard is one of several locations listed by the State Space Corporation Roscosmos to host a station of Russia’s warning system for tracking dangerous objects.
The space agency posted its need to purchase a "complex of specialized optical-electronic means," in Russia’s public procurement portal.
Interfax was first to report about Roscosmos’ purchase procurement document, while Radio Station Ekho Moskvy adds that the Arctic is a conflict region between Russia and the United States. In addition to Svalbard, other locations in the same system could be Cuba, Antarctica, Ethiopia, Mexico and a few other countries.
Roscosmos asks potential contractors to provide offers that include "various options for an expanded set of monitoring tools to be used of an automated system for warning about dangerous situations in near-earth space."
There are estimated to be about 18,000 objects larger than 10 centimeters in orbit, including 1,200 satellites, according to the Moscow State Technical University. Another 750,000 smaller objects at a size of about a centimeter are flying around the earth and could potentially pose a danger to satellites and space stations, Interfax reports.
The signing of the Svalbard Treaty in 1920 and its subsequent ratification in 1925 granted Norway sovereignty over the archipelago. Certain conditions were included in the deal. The archipelago was not to be used for "war-like purposes" and individuals and companies from signatory states were allowed to engage in economic activity. Russia is a signatory party to the Treaty and operates a coal mine and a settlement at Barentsburg. The town is also home to several scientific institutions, like the Kola Science Centre, a branch of Russia’s Academy of Science.
Last December, polar geopolitics expert Elizabeth Buchanan told the Barents Observer she predicts Moscow aims to enhance presence in Svalbard as part of a hybrid-strategy.
"The real push from Moscow when it comes to Svalbard will be occurring onshore, in plain sight, well within the bounds of the Treaty," Buchanan said.
A challenge with a tracking station for space debris at Svalbard is the possible multi-use, as such monitoring could theoretically also be used to look at military space objects or potentially ballistic nuclear missiles.
In November last year, Foreign Ministry spokesperson Maria Zakharova lashed out at Norway’s Svalbard policy, including the Svalsat satellite station on the mountain plateau above Longyearbyen.
According to Zakharova, the antennas are "technically equipped to perform dual-purpose tasks," she said, more than hinting the Norwegian satellite stations could have a military purpose in violation of the Svalbard Treaty.

Российская горно-металлургическая компания «Норникель» инициировала масштабное исследование по изучению биоразнообразия в трех российских регионах, в которых находятся производственные активы компании. Исследование будет проводиться учеными СО РАН, его цель - оценить текущее состояние биоразнообразия экосистем и выявить потенциальные угрозы, создаваемых производственными мощностями компании.

Russian mining company Nornickel has begun a large-scale biodiversity study to assess and define its environmental impact across its operations.
The company said the research would be carried by scientists from the Siberian Branch of the Russian Academy of Sciences and would cover the exploration, mining, production, transport, logistics, and energy facilities of its Norilsk, Kola and Trans-Baikal divisions.
The analysis will focus on defining the current biodiversity situation, identifying local indicators and endangered species, and pinning down any potential biodiversity threats posed by the company's production facilities.
The study will start with a series of on-site studies of terrestrial and aquatic ecosystems, including visual inspection sample collection followed by physical, chemical and combined analysis of samples.
Stanislav Seleznev, Nornickel vice president for Ecology and Industrial Safety, said the study would be "unprecedented in scale and make a substantial contribution to science while also building a foundation for a corporate system to manage biodiversity impact."
Viktor Glupov, a corresponding member of the Russian Academy of Sciences, commented: "Biodiversity lies at the heart of all ecosystems and life itself.
"It is crucial that major industry players like Nornickel recognise its importance and support Russian science community and biodiversity studies across the country."
In December 2021, Nornickel unveiled a methodology and model for calculating the carbon of all its manufactured products, saying it has a duty as a metals producer to cut emissions.

С помощью уникальных мюонных датчиков, установленных на территории Данилова монастыря в Переславле-Залесском, ученые НИТУ «МИСиС» и Физического института имени П.Н.Лебедева РАН обнаружили два скрытых помещения, а в подземной части между двумя храмами на территории монастыря оказалась длинная полость - воздуховод или тайный проход.

Scientists from NUST MISIS and the Lebedev Physical Institute of the Russian Academy of Sciences deciphered the final readings of a series of unique muon sensors installed on the territory of the Danilov Monastery in Pereslavl-Zalessky (Russia). The devices have found two previously unknown rooms, which, presumably, can be ancient crypts or monastic cells. In the underground part between two temples on the territory of the monastery, a long cavity was found. It may be either an air duct or a secret passage.
Scientists from NUST MISIS and the Lebedev Physical Institute of the Russian Academy of Sciences with the assistance of the Commission for Work with Universities and the Scientific Community under the Diocesan Council of Moscow completed a study of the unknown premises of the Danilov Monastery in the city of Pereslavl-Zalessky by muon radiography.
The ancient city of Pereslavl-Zalessky, founded in 1152 by Prince Yuri Dolgoruky on the shores of Lake Pleshcheyevo, is known for its monuments of ancient Russian architecture of the 12th-17th centuries. Holy Trinity Danilov Monastery is the youngest of the surviving monasteries and was founded in 1508. Ancient documents, including floor plans, have been lost, and buildings and underground spaces require special study.
The method of muon radiography based on emulsion track detectors allows solving this problem in an accessible way, without destroying buildings during excavations. Muons are elementary particles of cosmic origin that can penetrate the soil to a depth of 2 kilometers. This feature of the propagation of atmospheric muons allows to use them for "remote" studies of the structure of the natural and industrial object on a large scale.
"Registration of changes in the density of matter inside the object is carried out by the ionizing radiation passing through the object on special detectors (in our case, photo emulsion layers) that are sensitive to this radiation," said Natalia Polukhina, Doctor of physical and mathematical sciences, NUST MISIS leading expert and a chief researcher at the Lebedev Physical Institute, scientific leader of the project. "With the help of 22 unique sensors installed in November 2020, we have detected several new objects in the underground space between and below the two temples. Unknown voids that are absent on the floor plan were found in the basement of the Church of the Praise of the Mother of God built at the end of the 17th century. In addition, a large longitudinal cavity was found between this church and the Church of All Saints. In front of the temple itself, there is a rectangular room, as well as a small void between the basement and the first floor".
At the end of December 2021, scientists scanned data from 22 detectors, performed a physical analysis of the results, and presented the experimental results in the form of 3D models of the buildings and the surrounding areas.
"The underground cavities found outside the temples almost certainly are burial crypts. Danilov Monastery was originally founded on a cemetery, and subsequently many quite wealthy people wished to be buried here, and they could be buried not just in an earthen grave, but in a crypt - an underground room lined with brick. There is evidence that in recent times the ground on the territory of the monastery sagged in places, filling underground voids, and all these cavities likely have a similar origin. As for the voids inside the walls, the buildings of the monastery have undergone many repairs and redevelopments. Basement furnaces were being built and destroyed, the purpose of the technical premises was changing, there were big changes during the restoration after fires. It is difficult for me to understand what the purpose of the accessible premises was, and it is even more difficult to guess about the invisible voids,"- commented Hegumen Panteleimon (Korolev), prior of the Holy Trinity Danilov Monastery, Ph.D. in theology.
Muon radiography is used in applied research all over the world, in particular, as a promising addition to geophysical and geological methods in the analysis of volcanic, seismic and karst processes, in mineral exploration, in the field of nuclear safety for radiation monitoring of nuclear power plants, for non-destructive testing of industrial facilities.

Ученые Центрального сибирского ботанического сада СО РАН, Томского государственного университета, Института химической биологии и фундаментальной медицины СО РАН, Ботанического института имени В.Л.Комарова РАН, Института физиологии растений имени К.А.Тимирязева РАН и Института ботаники Китайской академии наук исследовали химический состав листьев весенника длинноножкового (Eranthis longistipitata), произрастающего в Средней Азии, и обнаружили в них кумарины и фурохромоны. Эти соединения достаточно редки и представляют интерес для фармакологии, поскольку обладают антиоксидантным, противоопухолевым и другими полезными свойствами.

Scientists from Central Siberian Botanical Garden, Siberian Branch of Russian Academy of Sciences; Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences; Komarov Botanical Institute, Russian Academy of Sciences; K.A. Timiryazev Institute of Plant Physiology RAS; and Institute of Botany, Chinese Academy of Sciences investigated the chemical constituents of Eranthis longistipitata and discovered coumarins and furochromones in its leaves. These compounds have antioxidant, antitumor, and other useful effects. The research is supported by the Russian Science Foundation and the results are published in the International Journal of Molecular Sciences.
Eranthis longistipitata belongs to a buttercup family and grows in Central Asia. It was first described in 1870 by a Russian botanist, Eduard Regel, but along with other species of the Eranthis genus, it is not very well-studied.
This investigation used liquid chromatography coupled with high-resolution mass spectrometry on samples collected in Kirgizia. This method is very accurate and sensitive and identifies both known and previously unknown constituents.
More than 160 compounds were found in the leaves of Eranthis longistipitata, of which 72 were identified to the class level and 58 to the individual-compound level. Among them, 19 compounds were identified as flavonoids. These compounds are important because they prevent cardiovascular diseases and even serve as a basis for drugs against venous insufficiency. Eranthis longistipitata leaves also have fatty and organic acids, amino acids, sugars and other compounds. However, the most interesting are coumarins and furochromones - two molecular classes, some of them discovered in Eranthis longistipitata (and the Eranthis genus in general) for the first time.
"In comparison to other common and well-studied compound groups, furochromones and coumarins are quite rare and are of interest to pharmacology," said Andrey Erst, Candidate of Sciences in Biology, senior researcher at Tomsk State University. "For example, coumarins found in the Eranthis longistipitata exhibit antioxidant, antitumor, and antiapoptotic effects. Chromone derivatives have anti-inflammatory, antiviral, antitumor and antispasmodic effects and are used as antioxidants. Moreover, due to their photochemical properties, they can be used as fluorescent labels in biochemical experiments and clinical medicine."
Metabolome studies are a new field in botany studies that investigates collections of small molecules in a living organism. Scientists from the US and China actively study substances formed as a result of all biochemical reactions in plants. In Russia, TSU Laboratory Herbarium was one of the first to practice this method.
Currently, technologies allow creating raw material of Eranthis using tissue culture. That is why scientists believe that the complex study of these plants has not only theoretical but also practical application.

Группа американских, британских и российских астрономов обнаружила одну из самых ярких сверхновых звезд, известную как AT2020mrf. Она в 10 тысяч раз ярче в рентгеновском диапазоне, чем типичная сверхновая.

The night sky is filled with blips and flashes, a constantly changing sea of lights. Some of these changes are from Earth-bound happenings such as aircraft flying overhead, but some are from distant sources in space. Astronomers hunt for these fleeting phenomena, known as astronomical transients, by observing the sky regularly and looking for differences that appear.
Researchers recently found a transient that outshines all others like it - a supernova known as AT2020mrf. They described their discovery in a paper posted on the preprint server arXiv.org last December and submitted to the Astrophysical Journal. They also presented it at a virtual press conference at the 2022 American Astronomical Society meeting in January. This supernova was one of the brightest and most energetic stellar deaths ever seen, and it might provide a rare glimpse into how massive stars give birth to some of the universe’s strangest objects: black holes and neutron stars.
The biggest stars die in spectacular fashion. They explode with the energy of a nonillion (that is "1" with 30 zeros behind it) atomic bombs in a supernova, shining so bright that we can sometimes even see them in the night sky with our bare eyes. AT2020mrf was 10,000 times brighter in x-rays than a typical supernova. It followed a few other superbright events that have been observed in recent years - astronomers refer to them as "cow-like" supernovae, or "cows," after the first of their type discovered: AT2018cow. Unlike traditional supernovae, cows shine brightly in high-energy x-rays and radio emission (most supernovae shine brightest in visible light). But AT2020mrf was the brightest cow of the bunch - 20 times brighter than the original.
Astronomers Yuhan Yao and Shri Kulkarni, both at the California Institute of Technology, along with Anna Ho of the University of California, Berkeley, and Daniel Perley of Liverpool John Moores University in England, first spotted this explosion in June 2020 in visible-light images from the Zwicky Transient Facility (ZTF), an automated telescope at California’s Palomar Observatory. The bright spot they saw originally seemed like something unremarkable, and the astronomers ignored this event until almost a year later.
In April 2021 Russian scientists collaborating with Yao’s group noticed the same event while reviewing data from their Spectrum-Roentgen-Gamma (SRG) x-ray observatory. Their images from July 2020 showed x-rays at the same location as the bright spot in the ZTF data. Upon hearing the news, Yao’s mind jumped straight to the mysterious cow-like events because they are the only type of supernova known to emit so many x-rays. Although a year had passed, the initial explosion from AT2020mrf was so incredibly bright that Yao suspected she might still be able to see it with the Chandra X-ray Observatory. Her calculations were correct, and observations showed it clearly, glowing 200 times brighter than the original cow a year after AT2020mrf’s explosion.
"It was really very rewarding when SRG saw this source, because we had been thinking that maybe [cow-like events] can be discovered in the x-ray first," Yao says. "This is the first time that one was really discovered in the x-ray."
Astronomers are still puzzling out what makes these supernovae special. The current theory is that cows have a very active "central engine" - something left behind by the star’s core, such as a black hole devouring matter or a neutron star rapidly spinning, that provides energy to the supernova. They also have less material shrouding this central region than most exploding stars, providing a view of their interesting center.
The stars that produce cow-like events appear to spew out material as they approach their death, making the environment around them denser and the stars themselves a bit smaller. When they explode, there is less gas in the immediate area around the star’s core, allowing x-rays from the central engine to escape. The shockwave the supernova sends through the surrounding space heats up the newly dense environment, too, creating the radio emission astronomers observe. Yao thinks that maybe AT2020mrf was even brighter than most cows because it had thrown off even more mass, allowing the central engine to shine through so brightly in x-rays.
"AT2020mrf is indeed an exciting event, both for what it confirms about the growing class of [cow-like objects] and what it tells us about the diversity of these mysterious stellar explosions," says Brian Metzger, an astrophysicist at Columbia University and the Center for Computational Astrophysics.
With only four previously known cow-like events, AT2020mrf more firmly establishes this group as a new category of explosion. The recent blast also stands out from its classmates, showing the fascinating diversity of stellar deaths. Although scientists understand the broad strokes of how massive stars die, the details are still fuzzy. This is especially true for certain stages of the end of a star’s life, such as the silicon burning stage, the last round of fusion a large star can complete, when it fuses silicon together to create iron. This period lasts only around 18 days out of the star’s million- to billion-year lifetime. Cows may provide a window into that hard-to-observe time frame and sharpen our understanding of how black holes and neutron stars are born within supernovae.
AT2020mrf and the other cows are also simply thrilling to scientists. "I like the excitement when I just see how one source is different from all others," Yao says. "You know, maybe once in a lifetime, you’ll find one of those events, and you need to take action. You need to stay on top of everything to tell the story of the object." Future observations with the Vera C. Rubin Observatory, an upcoming sky-surveying powerhouse, and other telescopes will hopefully give astronomers even more information to work with.

Международная группа астрономов при участии сотрудников Института космических исследований РАН обнаружила уникальное явление - наклонную черную дыру. Ось ее вращения отклонена от оси орбиты, по которой дыра движется вокруг звезды-компаньона, более чем на 40 градусов.

Scientist Prof. Dr. Svetlana Berdyugina, Professor of Astrophysics at the University of Freiburg and Director of the Leibniz Institute for Solar Physics (KIS), together with an international team of astronomers, has reliably measured for the first time a large difference between the rotation axis of the black hole and the axis of the orbit of the binary star system named MAXI J1820+070. The black hole's rotation axis is tilted by more than 40 degrees with respect to the axis of the star's orbit. "This finding challenges current theoretical models of black hole formation," Berdyugina says. The team published their findings in the journal Science.
Astronomers previously assumed a small angle
"The difference of more than 40 degrees between the orbital axis and the spin of the black hole was completely unexpected. Scientists have often assumed that this difference is very small when modeling the behavior of matter in a curved period around a black hole," Berdyugina explains. The new finding forces astronomers to add a new dimension to their models.
Polarization opens new path to understanding black holes
The research team made its discovery with the astronomical polarimeter DIPol-UF, an instrument for measuring the angle of the optical rotation of light. It was built by the Leibniz Institute for Solar Physics (KIS) and the University of Turku/Finland. It was finally put to use in the Nordic Optical Telescope on La Palma, Spain. "Our polarimeter used, DIPol-UF, is unique in its ability to measure optical polarization with the precision and accuracy of a few parts per million. Determining the orbital orientation of black holes based on polarization opens a new path to understanding their formation and physics," Berdyugina explains.
Astronomers observed jets in the radio- and X-ray range
The black holes in binary star systems were formed by a cosmic cataclysm - the collapse of a massive star. Now, the researchers noted how a black hole drags matter from the nearby, lighter companion star orbiting the system's gravitational center. Bright optical radiation and X-rays as the last sigh of infalling material were seen, as well as radio emission from the jets ejected from the system. By tracking the luminous gas streams, the jets, in the radio and X-ray range, the scientists were able to pinpoint the direction of the black hole's rotation axis.
In addition to Svetlana Berdyugina, the research project involved researchers from the University of Turku/Finland, the Space Research Institute of the Russian Academy of Sciences/Russia, the University of Stockholm/Sweden, Liverpool John Moores University/England, Radboud University/Netherlands, the Netherlands Institute for Space Research/Netherlands, the University of Denver/USA and the Universidad de La Laguna/Spain.

предыдущий месяц

1998-2022

следующий месяц