3480 - MILKY WAY - mysterious center of our galaxy?

 3480  - MILKY WAY  -  mysterious center of our galaxy?   Discovering the center of the Milky Way Galaxy all began all began with the discovery of Sagittarius A*, a persistent radio source located at the Galactic Center of the Milky Way that turned out to be a supermassive blackhole (SMBH). 

-------------  3480 -  MILKY WAY  -  mysterious center of our galaxy?

-  This discovery was accompanied by the realization that the blackhole exist at the heart of most galaxies, which account for their energetic nature and the hypervelocity jets extending from their center. Since then, scientists have been trying to get a better look at Sag A* and its surroundings to learn more about the role blackholes play in the formation and evolution of our galaxy.

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-  This has been the goal of the GRAVITY collaboration of astronomers that have been studying the core of the Milky Way for the past thirty years. Using the ESO’s Very Large Telescope Interferometer (VLTI), this team obtained the deepest and sharpest images to date of the region around Sag A*. 

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-  These observations led to the most precise measurement yet of the blackhole’s mass and revealed a never-before-seen star that orbits close to it.

This unique instrument combines the light of all four 8.2-meter (27 ft) telescopes at the Very Large Telescope’s (VLT) located at the Paranal Observatory in Chile – a technique known as interferometry. 

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-   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 atronomers were using a machine-learning technique called “Information Field Theory“. This consisted of modeling how the real light sources would appear, how GRAVITY would observe them, then comparing the simulated results to the actual observations. This allowed them to acquire highly-accurate measurements of Sag A* and images of Galactic Center that were 20 times sharper than any made by the individual VLT telescopes alone.

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-  Images obtained by the GRAVITY instrument between March and July 2021, showed stars orbiting very close to Sgr A*, the supermassive black hole at the heart of the Milky Way.  This included “S29“, which holds the record for making the closest and speediest approach around Sag A* ever observed. 

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-  This star , “S29” made its nearest pass in late May 2021, passing within 8 billion miles,  or 90 times the distance between the Earth and Sun (90 AU) – and achieving a velocity of 8,740 km per second (5,430 miles per second).

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-   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.

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

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-  Originally proposed by Albert Einstein in 1916, General Relativity provides a geometric explanation of gravitation and its effect on space-time. Since then, scientists have sought opportunities to test this theory under the most extreme conditions, which super massive blackholes provide.

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-  These latest observations confirmed that the stars follow paths predicted by General Relativity perfectly. From this, the team was able to constrain the mass of Sag A* to 4,300,000 Solar Masses.

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-   The distance to Sagittarius A* --------   27,000 light-years from Earth.

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-   Further observations of the Galactic Center will be possible in the coming years as the GRAVITY instrument is upgraded with the installation of GRAVITY+. This upgrade will push the sensitivity of the VLTI even further and reveal fainter stars that orbit even closer to Sag A*.

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-  The team aims to eventually find stars that orbit so close to Sag A* that they are subject to the gravitational effects caused by the blackhole’s rotation. 

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-   The Extremely Large Telescope (ELT) in the Atacama Desert in northern Chile. Once it is complete by 2027, the ELT will be the most powerful observatory in the world and allow for the most precise measurements of these stars’ velocities. It will be joined by the Giant Magellan Telescope (GMT), which is scheduled for completion by 2025.

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-  Thee inner 600 light years of our galaxy is a maelstrom of cosmic radiation, turbulent swirling gas clouds, intense star formation, supernovae, huge bubbles of radio energy, and of course this giant supermassive blackhole. 

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-  The new “MeerKAT”  image of the Galactic center region is shown with the Galactic plane running horizontally. MeerKAT is located in South Africa which has a vantage point of the galaxy’s center 25,000 light years away toward the constellation Sagittarius. 

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-  MeerKAT sees the Universe in radio waves which penetrate interstellar dust normally obscuring this region of space. An image  is the result of 144 hours of telescope observation and 70 terabytes of raw data. Created from 20 separate pointings, the image is a mosaic representing 6 square degrees of sky, the equivalent of 30 full Moons spanning 4 full Moons wide. If your eyes were sensitive enough to radio waves, this is what the galaxy would look like above you.

-  The Milky Way is a flat disk of hundreds of billions of stars with a bulging central core. Within the core exists a region called the “Central Molecular Zone” or CMZ with gas densities and turbulence 10-1000 times what you find in outer disk of the Milky Way and cosmic radiation levels equally higher than the rest of the galaxy. 

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-  Clusters of young massive stars are being created from fresh gas drawn toward the CMZ. Some of these massive stars have already exploded in these clusters as supernovae.

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-  Much of what we’re observing in the heart of the galaxy are familiar objects, stars exploding and gas flowing, but,  there are mysterious structures unique to this region we don’t fully understand. 

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-  Reaching out from the Milky Way’s core are giant magnetic tendrils, like strands or filaments,  up to 150 light years in length. They appear in pairs or clusters like “strings on a harp” separated from each other by about 1 AU (the Earth’s distance from the Sun), and act like wires conducting electrons accelerated to near the speed of light.

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- MeerKAT’s new image has uncovered 1000 more filaments – 10 times more than previously known. The filaments are difficult to see as they blend into the rest of the other structures and shapes of turbulent gas and star forming regions at the center of the galaxy.

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-  Because the filaments are magnetic, the flow of electrons along their length creates a unique signature of radiation that can be detected by MeerKAT, Synchrotron radiation.

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-   Synchrotron radiation is generated by the motion of high speed electrons through a magnetic field. This unique radiation allows the filaments to be teased out in images from other structures. 

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-  What are these filaments, what is accelerating electrons along their length, and why are they unique to the center of the galaxy?

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-   Lurking at the centre of the Milky Way is a supermassive blackhole. Blackholes come in a different varieties:  Supermassives weigh in at millions or even billions of times the mass of our Sun and are typically found in the centers of galaxies.

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-   Extending outward from the central region of the Milky Way are two large bubbles of gas emitting radio waves. They are symmetrical, forming an hourglass rising above and below the galactic plane.  This cirrus cloud-like emission from the Galactic center super bubble. This is traversed by a complex of many parallel filaments.

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-   MeerKAT found these radio bubbles in 2018 which extend a thousand light years outward from the central region and are thought to be created by a massive outburst from our blackhole about 100,000 to a million years ago.  It was powerful enough to send two  bubbles surging outward from the galaxy’s disk. While large black holes feed, huge amounts of energy are released that could create bubbles like these.

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-  There have also been outbursts of energy from the supernovae explosions and star formation in this region. It’s possible the filaments are created by the interaction of both the radio bubbles and star formation as the magnetic fields of energized gases expanding from the blackhole become entangled with outbursts from stellar formation and explosions. The blackhole’s outbursts also accelerate electrons along the length of the filaments themselves.

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-   If an interaction between the blackhole outbursts and supernova explosions creates the filaments, that interaction would explain why the filaments are unique to this part of the galaxy. They also seem to appear only within the radio bubbles themselves. 

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-  The filaments have also captured cosmic rays, high energy particles created by stars, in their magnetic fields. The particles can be dated essentially leaving a time stamp on the filaments. The MeerKAT images make it possible to catalogue each of the filament clusters to learn more about them and therefore the story of the center of our galaxy.

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-   As the gas approaches the black hole, it is heated beginning to ionize where electrons are stripped from the gas. The ionized gas appears as a “mini-spiral”  within five light years of the central blackhole.  This cloud of ionized gases and synchrotron radiation swirling about our black hole is light years across. 

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-  In the early 1930’s astronomer Karl Jansky first detected radio emission from the galactic center. That observation, considered the birth of radio astronomy, was the earliest version of what MeerKAT is observing now. It’s possible some of those radio emissions Jansky detected were the first observation of the blackhole at the center of our galaxy.

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-  We’ve come a ways since Jansky’s radio telescope built literally on Ford Model-T wheels.   Inaugurated in 2018 with 64 antennae spread over 8 kilpmeters of the Northern Cape of South Africa, MeerKAT is the most sensitive radio telescope of its kind. Bet

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-  This unprecedented new telescope image of the Milky Way galaxy's turbulent center has revealed nearly 1,000 mysterious strands dangling in space.  Stretching up to 150 light years long, the one-dimensional strands (or filaments) are found in pairs and clusters, often stacked equally spaced, side by side like strings on a harp.

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-   Using observations at radio wavelengths astronomers discovered the highly organized, magnetic filaments in the early 1980s. The mystifying filaments comprise cosmic ray electrons gyrating the magnetic field at close to the speed of light. But their origin has remained an unsolved mystery ever since.

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-  Now, the new image has exposed 10 times more filaments than previously discovered, enabling astronomers to conduct statistical studies across a broad population of filaments. 

Astronomers finally see the big picture, a panoramic view filled with an abundance of filaments. 

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-  To construct the image with unprecedented clarity and detail, astronomers spent three years surveying the sky and analyzing data at the South African Radio Astronomy Observatory (SARAO). Using 200 hours of time on SARAO's MeerKAT telescope, researchers pieced together a mosaic of 20 separate observations of different sections of the sky toward the center of the Milky Way galaxy, 25,000 light years from Earth.

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-   Along with the filaments, the image captures radio emissions from numerous phenomena, including outbursting stars, stellar nurseries and new supernova remnants.

The filaments are related to past activity of the Milky Way's central supermassive black hole rather than coordinated bursts of supernovae. The filaments also could be related to enormous, radio-emitting bubbles.

Astronomers can find the strength of magnetic fields, their lengths, their orientations and the spectrum of radiation.  But among the remaining mysteries is how structured the filaments appear. Filaments within clusters are separated from one another at perfectly equal distances, about the distance from Earth to the sun.

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-  These filaments almost resemble the regular spacing in solar loops.   We still don't know why they come in clusters or understand how they separate, and we don't know how these regular spacing’s happen. Every time we answer one question, multiple other questions arise.  They still don't know whether the filaments move or change over time or what is causing the electrons to accelerate at such incredible speeds.

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-  Astronomers are currently identifying and cataloging each filament. The angle, curve, magnetic field, spectrum and intensity of each filament. Understanding these properties will give the astrophysics community more clues into the filaments' elusive nature.

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February 26, 2022    MILKY WAY  -  mysterious center of our galaxy?         3480                                                                                                                                               

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-----------------------------  Monday, February 28, 2022  ---------------------------

3483 - MARS - after a year with Perseverance Rover?

  -  3483 -  MARS  -  after a year with Perseverance Rover?   The dramatic touchdown on Mars for the Perseverance rover and the Ingenuity helicopter occurred on February 18, 2021.   The incredible video astronomers received of the landing from the rover sky-crane lowering Perseverance to the planet’s surface is nothing short of amazing.

---------------------  3483  -  MARS  -  after a year with Perseverance Rover?

-   The Mars 2020 rover has been on Mars for over 355 Martian days, or sols. A Mars year is 668 sols.   In the past (Earth) year, the six-wheeled, one-armed nuclear-powered mobile science lab has traversing through Jezero Crater, a location that very likely contained a lake billions of years ago. 

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-   Perseverance has been using the drill on the end of its robotic arm to collect samples of Martian rocks. Collecting these samples is the first step of an eventual Mars Sample Return campaign.  The samples Perseverance has been collecting will provide a key chronology for the formation of Jezero Crater.

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-  Jezero features some of the oldest rocks Mars scientists have been able to study up close. The scientists say those rocks will have recorded and preserved Mars’ past environments, and perhaps even signs of ancient microscopic life.

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-   Bringing back a sample from this heavily cratered surface in Jezero could provide a tie-point to calibrate the Mars crater dating system independently, instead of relying solely on the lunar one.

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-  Perseverance broke a record for the most distance driven by a Mars rover in a single day, traveling almost 1,050 feet. This took place on February 14, 2022, the 351st Martian day, or sol, of the mission. 

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-   The rover performed the entire drive using “AutoNav“, the self-driving software that allows Perseverance to find its own path around rocks and other obstacles.

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-  One of the biggest surprises of the mission has been the rover’s buddy, the Ingenuity Mars Helicopter. No one knew for sure it would work to fly the tiny helicopter in the thin Martian atmosphere, and the original plan had the helicopter taking up to five flights over the span of about 30 days. 

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-  Instead, ‘Ginny’ has now completed 19 flights over the past 10 months and is still going strong. The team says the helicopter is providing a new perspective of Martian terrain and helping Perseverance’s team to plan the path ahead.

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-  Perseverance will actually be heading back towards its landing site. This back-tracking was in the mission plan, as the team wanted to first explore a rocky portion of the crater floor called “South Séítah“. That was the first phase of the mission, which will soon be wrapping up.

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-  The second phase of the rover’s mission will be to study the remains of a fan-shaped delta formed by an ancient river as it fed the lake in Jezero Crater. The safest way to get to the delta is by backtracking, since the other route would mean Perseverance would have to cross risky sand dunes and other rough terrain.

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-   Scientists want to get to the delta because they normally accumulate sediment over time, potentially trapping organic matter and possible bio-signatures, or signs of life, that may be in the environment.

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-   When it makes this destination, which the mission expects to reach in the summer of 2022, will be a highlight of the year.

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February 27, 2022     MARS  -  after a year with Perseverance Rover?       3483                                                                                                                                               

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--  email feedback, corrections, request for copies or Index of all reviews 

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Sunday, February 27, 2022  ---------------------------

3481 - SOLAR ENERGY - is about to Change?

  -  3481 -  SOLAR  ENERGY  -  is about to Change?    A big change is about to happen in solar cell technology.  Solar cell costs are coming down dramatically and at the same time electric rates are increasing.  The lines are about to cross.  A third generation of solar cells will hit the market that will be 4 times more efficient and 1/3 the cost.  

---------------------  3481  -  SOLAR  ENERGY  -  is about to Change?

-  This review is about two technologies that make this happen:  Multiple junction solar cells coupled with telescopic concentration of sunlight in solar arrays.

-   Pacific Gas and Electric is increasing its rates, tracking the rising cost of natural gas.  California politicians are “preventing” drilling for oil, installing nuclear reactors, burning coal, using gasoline engines all in the name of limiting pollution in our environment.  

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-  The limited supply of natural gas is not enough to sustain today’s low prices.  Wind, tides, geothermal are all too small to keep up with demand.  Solar photovoltaic’s are the most likely alternative to economically and quickly add  to our energy supply.

-  Today 95% of the solar photovoltaic cells generating electricity are using “single junction silicon“.  Costs have come down significantly since 1970 when the integration process was first developed.  

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-  Known as MOCVD, “Metal Organic Chemical Vapor Deposition” process.  It was in full production in 1980;s  Systems are still only 5 to 19% efficient and the cost, at best,  is 60 cents per kilowatt-hour.   

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-  The total energy to manufacture the cells was more than they would produce over their 25 year lifetime.  PG&E electric rates today are from 12 cents to 23 cents per kilowatt-hour depending on how much electricity you use.  Things are about to change with triple junction solar cells demonstrating 40% efficiency and 22 cents per kilowatt-hour.

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-  There are over 50 companies around the world working on these next generation products.  By using triple junction cells manufacturing integrates three solar cells into one.  Each cell is optimized for a different band of wavelengths of light, red light, blue light and yellow light.  

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-  A design similar to telescopes is used to concentrate sunlight on a single solar cell increasing the incident light by a factor of 1,000.  So, far fewer solar cells are needed.  Each 4 inch wafer contains 3,106 of these 1.5 mm solar cells.   

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-  Manufacturing efficiencies allow building the telescopes in a single stamp mold of glass and aluminum, with passive cooling, no moving parts and 35 year life expectancies, you have a product for energy change.

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-  The three junction cells are built on top of each other. Sunlight hit’s the first cell of  “Gallium Indium Phosphide” that is optimized for 350 to 660 nanometer wavelengths, which is ultraviolet, blue and green color light.  

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-  Photons not absorbed pass through to the second layer below that is “Gallium Arsenide” optimized for 660 to 880 nanometer wavelengths, yellow to red color light. 

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-   The bottom layer is a “Germanium” cell optimized to 880 to 1,900 nanometers wavelengths, red to infrared light.  Actually, the MOCVD integration process requires over 110 individual layers to match transitions between the three cells and to manage current and heat transfers.  With the 1,000 times magnification of light on to these cells normal silicon crystals would just melt.

-  The light concentration is actually similar to a telescope design called the Cassegrain reflector telescope.  There are two basics types of telescopes, reflecting and refracting.  Refracting uses lenses but these are not well suited for solar cell arrays because the lens itself reflects and absorbs the light.  Plastic lenses get cloudy with age.  The reflecting telescope uses mirrors.  

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-  The Cassegrain reflectors uses a large primary mirror with a hole in the middle.  The parabolic shape of the mirror reflects parallel incident light beams on to a much smaller secondary mirror above it. 

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-   The secondary mirror in turn reflects concentrated light back down through the hole and on to the single solar cell that is only 1.5 millimeters square.  The solar cell receives 500, to 1,000, to 2,000 times more light depending on the array design.

-  Now imagine shrinking this Cassegrain telescope so that it is only 6 millimeters thick. Next imagine that the mirrors are not mounted separately but imbedded in a double sided mold of glass and aluminum.  This is a very efficient and durable manufacturing process.

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-  The Sun sends us energy in a light spectrum spreading from 400 to 2,000 nanometers wavelength. When it reaches our atmosphere its intensity is 1,353 watts per square meter.  Gases in our atmosphere absorb some of this energy.  This is what heats our atmosphere and gives us this temperate climate of 15 C. 

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-  Most of the energy still reaches the surface of Earth and even at higher latitudes with the light going through more atmosphere and striking at an angle we get 850 watts / meter^2 in California.  

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-  With solar panels that are 40% efficient it could produce 340 watts of electrical power for each square meter.  This electric power can be pumped into the PG&E electric grid or stored in batteries when not being consumed in the household.  Like Santa’s sleigh alternative energy will soon be arriving on your roof.

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-  One of the reasons we need electric cars is efficiency.  Gasoline powered cars are only 8 to 9 % efficient.  Oil burned in electric power plants is 42% efficient.  That is four times more oil available for other purposes like medicines, plastics, or lubrication.

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-  The world is consuming 85,200,000 barrels of oil per day.  By 2030 it will be 115,000,000 per day.  Peak oil has passed and the remaining oil will cost us more and more as it is harder to find and harder to produce.

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-   The U S  consumes 24% of the world’s oil and produces 8%.  The rest we buy from other countries costing us over $700,000,000,000 each year.  Money we just burn.  Money we need for other purposes.

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-    These solar cells require rare Earth metals that too are in short supply. Won’t these become similar to oil?  Not likely.  First because we use so little in the integration process.  Germanium is the most volume used.  

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-  We get most of it from scraping the chimney flues of Aluminum and Coal burning plants.  Coal is a good source for Germanium.  We want clean coal technology.  We should extract the Germanium first before the clean coal goes into the plant to be burned to produce electricity.

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-  Most solar cells, or photovoltaic cells, respond to only a narrow part of the Sun’s spectrum. Our eyes only respond to 700 nanometers to 400 nanometers, from red to blue visible light. The best techniques in solar cells respond from 600 to 900 nanometers. 

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-  But things are about to change. The Sun sends us an electromagnetic spectrum extending far below 700 nanometers into the infrared and far above the 400 nanometers into the ultraviolet.

-  The frontier of today’s solar cell technology is to layer several different solar cells on top of each other with each cell optimized for its part of the spectrum.  Magnification mirrors are often used to concentrate the sunlight on to the small area of the solar cell. 

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-  Earlier solar cells had efficiencies from 10 to 14 % , these recent improvements have got them to 20% efficiencies. Military budgets and laboratories have got cells to 40% efficiencies but the trick is to make them cost effective in high volumes. That is what a new polymer might do for us. 

-  The polymer is “oligothiophene“, doped with molybdenum and tungsten.  This polymer will respond to sunlight wavelengths from 300 to 1000 nanometers. Most solar cell materials fluoresce, that is sunlight striking the atoms excites electrons into a higher energy state. The electrons drop back down to their ground level state and release photons with frequencies matching the energy gaps that they just jumped. 

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-  (See Review 2709 “How an Atom Works“, Measuring How an Atom Works“ ) 

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-  Normally you cannot see the solar cells fluoresce because it is mostly in the infrared part of the spectrum and the light is too feeble compared to the bright sunlight.

Some solar cell designs have figured out ways to boost efficiency by reuse of these infrared fluorescence light photons.  

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-  The way the solar cell produces electricity is that some of these electrons become excited enough to break free form the nucleus of their host atom and become “free electrons“. Given a potential gradient and these free electrons will migrate producing an electric current. 

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-  Usually with fluorescence the electrons only remain free electrons to be captured for a trillionth of a second. They often drop back down into the ground level state before serving a useful purpose as electric current. This is why solar cells are not 100% efficient.

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-  The new polymer material does not fluoresce, it “phosphoresces“. This is like the glow seen in kid’s toys. The electrons phosphorescence hold on their freedom longer, a few microseconds. These longer lived free electrons are going to greatly improve the efficiency of solar cells.

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-   The polymer is still manufactured in a thin film state and it will still take several years to produce working solar cells out of this material. However, with the demand for alternative energy sources you can bet these higher efficiency and much cheaper solar alternatives are on their way to market.  We are still waiting.  

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February 26, 2022       SOAR  ENERGY  -  is about to Change?     958    995  3481                                                                                                                                             

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-----  Comments appreciated and Pass it on to whomever is interested. ---

---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----  

--  email feedback, corrections, request for copies or Index of all reviews 

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Saturday, February 26, 2022  ---------------------------

3468 - NEUTRINOS - what is their little mass?

  -  3468  -  NEUTRINOS  -  what is their little mass?    Neutrino mass discovered to have an upper limit of 0.8 electronvolt (eV). A new model-independent laboratory method allows KATRIN to constrain the mass of these "lightweights of the universe" with unprecedented precision.

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-------------  3468  -  NEUTRINOS  -  what is their little mass?

-  Neutrinos are arguably the most fascinating elementary particle in our universe. In cosmology they play an important role in the formation of large-scale structures, while in particle physics their tiny but non-zero mass sets them apart, pointing to new physics phenomena beyond our current theories.

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-   Without a measurement of the mass scale of neutrinos our understanding of the universe will remain incomplete.  This is the challenge the international “KATRIN” experiment as the world's most sensitive scale for neutrinos. It makes use of the beta decay of tritium, an unstable hydrogen isotope, to determine the mass of the neutrino via the energy distribution of electrons released in the decay process. 

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-  The 70 meter long experiment houses the world's most intense tritium source as well as a giant spectrometer to measure the energy of decay electrons with unprecedented precision.

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-  The high quality of the data after starting scientific measurements in 2019 has continuously been improved over the last two years, to 2022.  The experimental data from the first year of measurements and the modeling based on a vanishingly small neutrino mass match perfectly  A new upper limit on the neutrino mass of 0.8 eV can be determined.

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-  The development of a new detector system (TRISTAN) plays a specific role in  allowing KATRIN from 2025 on to embark on a search for "sterile" neutrinos with masses in the kilo-electronvolt-range, a candidate for the mysterious dark matter in the cosmos that has already manifested itself in many astrophysical and cosmological observations, but whose particle-physical nature is still unknown.

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-  Every second, about 100 trillion neutrinos pass through your body. These ghostly particles are fundamental to our understanding of the universe. But they’re extremely small, so small that scientists once thought they had no mass at all. 

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-  Neutrinos do have mass, however, and physicists have now managed to put a new upper limit on it: 0.8 electronvolts, or 0.8 eV. 

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-  Electronvolts are technically a measure of energy, but mass and energy are equivalent, as shown by Albert Einstein's most famous equation, E=mc^2.  For perspective, the mass of an electron is about 511,000 eV. And protons and neutrons tip the subatomic scales at over 938,000,000 eV.  Neutrino only 0.8 eV

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-  To find the 0.8 eV limit, the researchers turned to tritium, an isotope of hydrogen that has two neutrons in its nucleus. Tritium is unstable and radioactive, meaning that it decays into lighter forms of hydrogen. As it does so, it releases a number of particles. By watching those particles, the scientists found traces of the neutrino mass and pieced it together.

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-   KATRIN is a 230-foot-long experiment located at the Karlsruhe Institute of Technology in Germany. (KATRIN is an acronym for "Karlsruhe Tritium Neutrino Experiment.") 

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-  After watching tritium atoms decay and collecting data at KATRIN, the team found the neutrino mass upper limit to be 0.8 eV.

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-   Getting under the “1 eV line” is a major milestone.  That’s where theories predict neutrino masses should lie.  A lot of exciting particle physics takes place at masses under 1 eV, so probing this realm could help unlock the workings of the universe at the tiniest scales.

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February 25, 2022        NEUTRINOS  -  what is their little mass?                 3468                                                                                                                                               

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-----  Comments appreciated and Pass it on to whomever is interested. ---

---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----  

--  email feedback, corrections, request for copies or Index of all reviews 

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

-----------------------------  Friday, February 25, 2022  ---------------------------

3477 - STARS - biggest to fastest?

  -  3477  -  STARS  -  biggest to fastest?  We can only see within our own Milky Way Galaxy unless we have a good telescope.  One exception, we can see the Andromeda Galaxy on a good seeing night and that is 2,500,000 lightyears away.  The Milky way is 100,000 lightyears across.  

------------------------  3477  -  STARS  -  biggest to fastest?

-  Astronomers have determined that there is a massive Blackhole in both of these galaxies and in most every other galaxy they can find.

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-  Some galaxies are very active spewing out lots of energy.  That means their Blackholes are very active.  The Milky Way and Andromeda are not very active by comparison.  Really active galaxies spew out energy, radiation, in jets of tremendous power.  They get names like Quasars, Blazars, Magnetars, and more.   

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-  Astronomers think much of this power is generated by a rapidly spinning Blackhole.  They have found extreme rotation speeds that approach the speed of light.

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-  When a Blackhole with extreme mass, billions of times the mass of the Sun, and extreme gravity, and then extreme rotation speeds it causes the surrounding space and time to rotate with it.  This is called “frame dragging“. 

-

-   Then incoming gas enters this spinning vortex as ionized particles which in turn create tightly wound towers of powerful magnetic fields.  These magnetic fields channel the energy and inflowing gas into powerful gets that blast away at the poles approaching the speed of light.

-

-  Astronomers believe that rotating Blackholes are first created when to galaxies collide and merge.  This collision injects angular momentum into the system.  Once rotation starts in falling material causes the rotation speed to go higher and higher until it reaches near light speed.

-

-  Active black holes with too much energy can actually stall star formation in the entire galaxy.  Stars form from large clouds of cold gas.  The energy spewed out from these rotating blackholes heat the surrounding gas and stall star formation until things finally cool down.  There is still a lot of math to get through before this process is really understood.

-

-   Occasionally stars that are unfortunate enough to be close to these blackholes get ejected out of the galaxy.  Stars that get hurled away get reach velocities of 1,000,000 miles per hour.

-

-  There is one star ( HE0437-5439) that is 9 times the mass of the Sun and speeding away from the large Magellanic Cloud Galaxy at 1,600,000 miles per hour.  This is a young star, only 35 million years old.  Earth is 4,500 million years old.  Yet, this star has traveled 100 million lightyears from its source.

-

-  The concentration of elements in the Large Magellanic Cloud of stars are about one-half those of our Sun.  This hypervelocity star matches the LMC elements so that must be its origin.  Hypervelocity stars get their kick from interaction with a blackhole. 

-

-   Starting out as a binary system one star feeds off the other star until one acquires the mass needed for gravity to collapse it into a Blackhole.  The energy of the collapse is transferred to the other star sending it away at hypervelocity.

-

-    The Conservation of Energy requires that total energy remain constant.  Gravitational Energy plus Kinetic Energy remain constant.  The hypervelocity star gets the Kinetic Energy.

-

-  Astronomers have not yet found this particular Blackhole yet in the LMC, but, this hypervelocity star tells us that it is there.

-

-  What is the biggest star in the Universe?  We will never know.  The Universe is too big and we can only observe a small  part of it.  But, what is the biggest star we can observe in the Universe?  Our most observed star is our Sun.  It is 870,000 miles across.  By mass the Sun is 99.9 % of our entire Solar System. 

-

-   By volume you could fit 1,300,000 Earths inside the Sun . 

-

------------------------------  volume = 4/3* pi* r^3

-

------------------------------  Sun’s radius =  6.9599*10^8 meters

-

------------------------------  Earth’s radius =  6.378*10^6 meters,

-

------------------------------  Sun’s radius is 100 times larger.

-

------------------------------  Ratio  =  1.3*10^6

-

 -----------------------------    The Sun’s Radius is 432,000 miles

-

------------------------------  The Solar Mass is 2*10^30 kilograms,                              2,000,000,000,000,000,000,000,000,000 kg.

-

-  Eta Carinae is a monster star in our galaxy just 7,500 lightyears away.  It is 100 times the Solar Mass. and it is 4,000,000 times brighter than our Sun.  Its solar wind casts off 500 times the Earth mass every year.  Its radius is 400 times Solar Radius.  

-

-  Astronomers are certain Eta Carinae is about ready to explode as a supernova.  It is extremely hot, 25,000 Kelvin at its surface.  Our Sun is 6,000 Kelvin.

-

-  But, Eta Carinae is not the biggest star we have found in our galaxy.  VY Canis Majoris is 5,000 lightyears away and it is 2,100 time Solar Radius.  It takes light 8 hours to go across it.  It takes light only 8 minutes to reach us from the Sun.

-

-  There are likely more massive stars in our Milky Way Galaxy but we can not see them  because they are hidden by intergalactic gas and dust.  The largest stars are the coolest stars, that are still stars.  VY Canis Majoris is only 3,500 Kelvin.  Physics calculations are that the largest possible star is 3,000 Kelvin and 2,600 times Solar Radius.

-

-  It a star is less than 3,000 Kelvin it not a star, it is too cool to have nuclear fusion and to shine.  There could be something bigger out there that does not shine.  We have not found it unless you count Blackholes.  Blackholes have been found that are 1,000,000,000’s times Solar Mass.  And, they don’t shine.

-

February 23, 2022       STARS  -  biggest to fastest?       907    905       903        3477                                                                                                                                               

----------------------------------------------------------------------------------------

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-----------------------------  Thursday, February 24, 2022  ---------------------------

  -  3475  -  MILKY WAY  GALAXY  -  new pictures emerging?   An unprecedented new telescope image of the Milky Way galaxy's turbulent center has revealed nearly 1,000 mysterious strands, inexplicably dangling in space.  Stretching up to 150 light years long, the one-dimensional strands (or filaments) are found in pairs and clusters, often stacked equally spaced, side by side like strings on a harp. 

-------------  3475  -  MILKY WAY  GALAXY  -  new pictures emerging?

-  Observations at radio wavelengths discovered the highly organized, magnetic filaments in the early 1980s. The mystifying filaments comprise cosmic ray electrons gyrating the magnetic field at close to the speed of light. But their origin has remained an unsolved mystery ever since.

-

-  Now, the 2022 image has exposed 10 times more filaments than previously discovered.  This has allowed statistical studies across a broad population of filaments for the first time. 

-

-   Astronomers have studied individual filaments for a long time with a myopic view.  Now they can see a panoramic view filled with an abundance of filaments. Just examining a few filaments makes it difficult to draw any real conclusion about what they are and where they came from. This is a watershed in furthering our understanding of these structures.

-

-  To construct the image with unprecedented clarity and detail, astronomers spent three years surveying the sky and analyzing data at the South African Radio Astronomy Observatory (SARAO). Using 200 hours of time on SARAO's MeerKAT telescope, researchers pieced together a mosaic of 20 separate observations of different sections of the sky toward the center of the Milky Way galaxy, 25,000 light years from Earth.

-

-  Along with the filaments, the image captures radio emissions from numerous phenomena, including outbursting stars, stellar nurseries and new supernova remnants.

-

-   To view the filaments at a finer scale they used a technique to remove the background from the main image in order to isolate the filaments from the surrounding structures. The resulting picture was astounded.

-

-  While many mysteries surrounding the filaments remain astronomers have been able to piece together more of the puzzle. They specifically explored the filaments' magnetic fields and the role of cosmic rays in illuminating the magnetic fields.

-

-  The variation in radiation emitting from the filaments is very different from that of the newly uncovered supernova remnant, suggesting that the phenomena have different origins. It is more likely that the filaments are related to past activity of the Milky Way's central super massive blackhole rather than coordinated bursts of supernovae. 

-

-  The filaments also could be related to enormous, radio-emitting bubbles discovered in 2019.  This is the first time we have been able to study statistical characteristics of the filaments.   We can find the strength of magnetic fields, their lengths, their orientations and the spectrum of radiation.

-

-  Among the remaining mysteries is how structured the filaments appear. Filaments within clusters are separated from one another at perfectly equal distances, about the distance from Earth to the Sun.

-

-  They almost resemble the regular spacing in solar loops. We still don't know why they come in clusters or understand how they separate, and we don't know how these regular spacing’s happen. Every time we answer one question, multiple other questions arise.  The smarter we get the more we don’t know.

-

- We still don't know whether the filaments move or change over time or what is causing the electrons to accelerate at such incredible speeds.  They are currently identifying and cataloging each filament. The angle, curve, magnetic field, spectrum and intensity of each filament. Understanding these properties will give more clues into the filaments' elusive nature.

-

-  Best image ever taken of stars buzzing around the Milky Way’s Supermassive blackhole began with the discovery of Sagittarius A*, a persistent radio source located at the Galactic Center of the Milky Way that turned out to be a supermassive blackhole (SMBH). 

-

-  This discovery was accompanied by the realization that SMBHs exist at the heart of most galaxies, which account for their energetic nature and the hypervelocity jets extending from their center. Scientists have been trying to get a better look at Sag A* and its surroundings to learn more about the role SMBHs play in the formation and evolution of our galaxy.

-

-  This has been the goal of the GRAVITY collaboration, an international team of astronomers and astrophysicists that have been studying the core of the Milky Way for the past thirty years. Using the ESO’s Very Large Telescope Interferometer (VLTI), this team obtained the deepest and sharpest images to date of the region around Sag A*. These observations led to the most precise measurement yet of the blackhole’s mass and revealed a never-before-seen star that orbits close to it.

-

-  This unique instrument combines the light of all four 8.2-meter (27 ft) telescopes at the Very Large Telescope’s (VLT) located at the Paranal Observatory in Chile  Astronomers want to learn more about the blackhole 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 blackhole.

-

-  The astronomees have employed a machine-learning technique called “Information Field Theory“. This consisted of modeling how the real light sources would appear, how GRAVITY would observe them, then comparing the simulated results to the actual observations. This allowed them to acquire highly-accurate measurements of Sag A* and images of Galactic Center that were 20 times sharper than any made by the individual VLT telescopes alone.

-

-   During their observation period, which ran from March to July, 2021   Precise measurements of the stars that orbit Sag A* were made.  This included “S29“, which holds the record for making the closest and speediest approach around Sag A* ever observed. 

-

-  This star made its nearest pass in late May, 2021, passing within 13 billion kilometers (8 billion miles) ,or,  90 times the distance between the Earth and Sun (90 AU) and achieving a velocity of 8,740 km per second (5,430 miles per second). 

-

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

-

-    General Relativity provides a geometric explanation of gravitation and its effect on space-time. Scientists have sought opportunities to test this theory under the most extreme conditions.

-

-  These latest observations, combined with the team’s previous data, confirmed that the stars follow paths predicted by General Relativity perfectly. From this, the team was able to constrain the mass of Sag A* to 4,300,000  Solar Masses, the most precise estimate of the blackhole’s mass yet. 

-

-   The distance to Sagittarius A* =   27,000 light-years from Earth.

-

-  These latest results, which expand on thirty years of observations of our galactic center. 

further and reveal fainter stars that orbit even closer to Sag A*.   The ESO is  busy constructing the Extremely Large Telescope (ELT) in the Atacama Desert in northern Chile. 

-

-  Once it is complete, scheduled for 2027, the ELT will be the most powerful observatory in the world and allow for the most precise measurements of these stars’ velocities. It will be joined by the Giant Magellan Telescope (GMT), which is scheduled for completion by 2025.

-

-  The more we learn the more we need to know.

-

February 20, 2022    MILKY WAY  GALAXY  -  new pictures emerging?      3472                                                                                                                                               

----------------------------------------------------------------------------------------

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--  email feedback, corrections, request for copies or Index of all reviews 

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

-----------------------------  Tuesday, February 22, 2022  ---------------------------

  -  3473  -  EXOPLANETS  -  discoveries are accelerating?  A third planet was found orbiting nearby star , “Proxima Centauri”.  August, 2016, astronomers had discovered an exoplanet orbiting in neighboring Proxima Centauri. Based on Radial Velocity measurements ( Doppler Photometry), the discovery team estimated that the planet was roughly the same size and mass as Earth. 

-

----------------------------  more like us?

-------------  3473  -  EXOPLANETS  -  discoveries are accelerating?

-  In 2020, this planet was confirmed by follow-up observations.

-

-  In that same year, a second exoplanet (Proxima “c“) roughly seven times the mass of Earth (a Super-Earth or mini-Neptune) was confirmed.  They detected a third exoplanet around Proxima Centauri – Proxima “d“! This Mars-sized planet orbits about halfway between its host star and Proxima “b” and is one of the lightest exoplanets ever discovered.

-

-   In addition to confirming the existence of Proxima b, astronomers spotted the first hints of a signal corresponding to an object with a five-day orbit.  Since the signal was so weak, the team had to conduct follow-up observations with ESPRESSO to confirm that it was due to a planet. 

-

-  Similar to Proxima b and c, the planet was confirmed using the Radial Velocity Method, where slight changes in a star’s position indicate the possible presence of planets.

-

-   Proxima d has a minimum mass of 0.26 Earth masses (twice the mass of Mars), making it the lightest exoplanet ever measured using the Radial Velocity Method. Because Proxima b is so light, its gravitational influence is so small that it only causes Proxima Centauri to move back and forth at around 40 centimeters per second 

(        1.44 kilometers / hour;      0.89 miles per hour     ). 

-

-  It orbits its star at a distance of about 0.029 AU,     4 million kilometers;     

 2,485,485 miles, which is less than a tenth of Mercury’s distance from the Sun.

-

-  The Proxima Centauri star system consists of three confirmed exoplanets, with orbital periods of five days (Proxima d), eleven days (Proxima b), and five years (Proxima c). 

-

-  The radial velocity technique has the potential to unveil a population of light planets, like our own, that are expected to be the most abundant in our galaxy and that can potentially host life as we know it.

-

-   This discovery not only demonstrates the way exoplanet studies have grown by leaps and bounds in recent years. It has also made Proxima Centauri even more appealing to astronomers. 

-

-  With three exoplanets (in six years) discovered around this closest stellar neighbor, the research potential is immeasurable. These activities will benefit tremendously from the James Webb Space Telescope (JWST), which will start gathering light soon.

-

-  Exoplanet surveys using the ESPRESSO instrument will benefit from the Extremely Large Telescope (ELT), which is scheduled to become operational by 2027. Between its 39.3 meter,  (130 ft) primary mirror, 4.2 m (14 ft) secondary mirror, and an advanced suite of instruments ,which includes a spectrograph, coronograph, and adaptative optics.

-

-  Outside of our closest neighbor planetary system other planets have been found in the habitable zone of a White Dwarf star that is 117 lightyears away.

-

-  Most stars will end their lives as white dwarfs. White dwarfs are the remnant cores of once-luminous stars like our Sun, but they’ve left their lives of fusion behind and no longer generate heat. They’re destined to glow with only their residual energy for billions of years before they eventually fade to black.

-

-  Could life eke out an existence on a planet huddled up to one of these fading specters?

For life to exist around a white dwarf, the white dwarf would have to have planets in its slowly shrinking habitable zone.  These planets are in the habitable zone of the white dwarf about 117 light-years away. 

-

-   This is the first time astronomers have detected any kind of planetary body in the habitable zone of a white dwarf.    The researchers observed “WD1054-226” for 18 nights with the ESO’s New Technology Telescope (NTT) at their La Silla Observatory, observing dips in starlight as something passed between us and the star. 

-

-  They used the NTT’s ULTRACAM high-speed camera to capture data images of the white dwarf. They also examined data on the same star from NASA’s Transiting Exoplanet Survey Satellite (TESS.)

-

-  The team found dips in light that they interpret as 65 clouds of planetary debris. The clouds are evenly spaced and orbit the white dwarf every 25 hours. What causes such regularity? 

-

-  The researchers say that a planet must be there, which forces these debris clouds into a precise orbital pattern. They say the planet is similar in size to rocky planets in our Solar System and that it’s only about 2.5 million kilometers (1.55 million miles) from the star. That’s about 1.7% of the distance between Earth and the Sun.

-

-  Alongside the regular dips in starlight is an ever-present obscuration that the team says is debris in a planetary disk around the star. These structures are in a region that would have been overcome when the white dwarf went through its preceding red giant phase. 

-

-  It’s doubtful that any of these structures could have survived the red giant phase, so they must have formed more recently in the aftermath. If there is a planet in the habitable zone, it can’t be a hold-over from the star’s previous life as a main-sequence star. 

-

- If all of the circumstances lined up just right life would potentially have about two billion years to do its thing on the purported planet, with one of those billions in the future.

-

-  The first three nights of ULTRACAM observations of WD1054-226 shows a notable and easily recognized recurring feature, the double-dip structure that recurs every 25.2 hours, and occurs just before hours 2, 27, and 52.   Using this structure as a visual anchor, the adjacent, antecedent, and subsequent transits can all be seen to have the same morphology over all three nights.

-

-  These bodies are kept in an evenly-spaced orbital pattern because of the gravitational influence of a nearby major planet. Without this influence, friction and collisions would cause the structures to disperse, losing the precise regularity that is observed. A precedent for this ‘shepherding’ is the way the gravitational pull of moons around Neptune and Saturn helps to create stable ring structures orbiting these planets.

-

-   The possibility of a major planet in the habitable zone is exciting and also unexpected.  More evidence is necessary to confirm the presence of a planet. We cannot observe the planet directly, so confirmation may come by comparing computer models with further observations of the star and orbiting debris.

-

-  If there are indeed clouds of material orbiting the white dwarf, they’re likely outside the Roche limit.  Debris clouds probably come from collisions or tidal disruption events. From a dynamical and evolutionary perspective, the origin of the large occulting clouds is likely the result of tidal disruption or collisions in the vicinity of the Roche limit.

-

-  The “Roche Limit” is the distance a planet can get close to a star before being torn apart by the star’s gravity.

-

-   It’ll be up to further observations with the James Webb Space Telescope to provide better data. The JWST has the power to better define the debris disk and its components. But if there is a roughly Earth-sized rocky planet there, it’s an intriguing possibility with liquid water potential.

-

-  Marginally habitable situations may be relatively common in the Milky Way and the Universe. Life might arise countless times and never evolve the complexity that life on Earth has become. The Moons of our Solar System might harbor life for some time. Mars may have harbored life for some time.  Now, maybe, we can add white dwarf planets to that list.

-

February 20, 2022     EXOPLANETS  -  discoveries are accelerating?      3473                                                                                                                                               

----------------------------------------------------------------------------------------

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---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

-----------------------------  Monday, February 21, 2022  ---------------------------

3472 - ATOMIC CLOCKS - finding Dark matter?

  -  3472  -  ATOMIC  CLOCKS  -  finding Dark matter?    Atomic clocks work by tracking the energy levels of electrons. When an electron changes energy levels, it absorbs or emits light with a frequency that is identical for all atoms of a particular element.  Optical atomic clocks keep time by using a laser that is tuned to precisely match this frequency.

-------------  3472  -  ATOMIC  CLOCKS  -  finding Dark matter?

-  Atomic clocks are the most accurate instruments ever made.  The inaccuracies are measured in seconds lost in billions of years.  That seems impossible?  How would we know?

-

-  These instruments can measure time so precisely that they will only lose one second every 300 billion years.  This accuracy will  allow scientists to make for more exact measurements of gravitational waves, dark matter and other physics phenomena.

-

-  Optical lattice clocks are already the best clocks in the world, and here we get this level of performance that no one has seen before.   Generally speaking, atomic clocks are clocks that track the resonances of atom frequencies, usually the atoms of cesium or rubidium.

-

-   “Atomic clocks” work by tracking the energy levels of electrons. When an electron changes energy levels, it absorbs or emits light with a frequency that is identical for all atoms of a particular element.

-

-    “Optical atomic clocks” keep time by using a laser that is tuned to precisely match this frequency.

-

-  The new study created a multiplexed clock, which separated strontium atoms into a line in a single vacuum chamber. The laser on only a single clock, the laser excited electrons in the same number of atoms for only one-tenth of a second. But with two clocks at the same time, the atoms stayed excited for 26 seconds. 

-

-  The group then attempted to measure differences between clocks precisely, because two groups of atoms in slightly different environments will "tick" at different rates due to changes in magnetic fields or gravity. The team ran the experiment over 1,000 times to measure the difference, finding more precision in that measurement over time. 

-

-  Ultimately, the researchers detected a difference in the ticking rate between two atomic clocks "that would correspond to them disagreeing with each other by only one second every 300 billion years.

-

-  These researchers are putting a global network of the most precise timekeepers ever made to the task of hunting for dark matter, the invisible and largely intangible substance that researchers think makes up about five-sixths of all matter in the universe.

-

-  The existence of dark matter is suggested via its gravitational effects on the movements of stars and galaxies. However, it remains a mystery as to what it might be composed of, and projects ranging from the most powerful atom smasher ever built to vats of chilly liquid xenon have failed to find a trace of it so far. 

-

-  Scientists have largely eliminated all known particles as possible explanations for dark matter. One remaining possibility is that dark matter is made of a new kind of particle; another is that dark matter is not made of particles at all, but rather a field that pervades space much like gravity does. 

-

-  Previous research suggested that if dark matter is a field, structures could emerge within it, "topological defects" shaped like points, strings or sheets and potentially reaching at least the size of a planet. These structures might have formed during the chaos after the Big Bang, and essentially froze into stable forms when the early universe cooled down.

-

-  Now scientists are testing the existence of dark-matter fields by looking for disturbances in some of the most accurate scientific instruments ever constructed, atomic clocks. 

-

-  These instruments keep time by monitoring the quivering of atoms, much as grandfather clocks rely on swinging pendulums. Nowadays, atomic clocks are so accurate that they would lose no more than 1 second every 15 billion years, longer than the 13.8-billion-year age of the universe.

-

-  Interacting with a topological defect could make an atomic clock's atoms temporarily shake faster or slower. By monitoring a network of synchronized atomic clocks that are spread far enough apart for a topological defect to have an effect on some clocks but not others, scientists could detect the existence of these ghostly structures and measure some of their properties, such as their size and speed.

-

-  The researchers employed optical atomic clocks, which use laser beams to measure the motions of atoms when they are slowed down by cooling them to temperatures near absolute zero.

-

-   They calculated that passing through a topological defect could increase or decrease the fine-structure constant, which describes the overall strength of the electromagnetic force. Such changes would alter how atoms respond to lasers and the rate at which those clocks ticked.

-

-  Another possible explanation for dark matter is that its effects are caused by fields that vary in strength over time, which in turn lead to regular fluctuations in the strength of the electromagnetic field. Atomic clocks could detect such "coherently oscillating classical scalar fields“.

-

-  By analyzing four atomic clocks on three continents, in Colorado, France, Poland and Japan,  the researchers could look for subtle variations in the fine-structure constant with about 100 times greater sensitivity than previous experiments. However, they did not detect any signal consistent with dark matter.

-

-  One of the major problems of optical atomic clocks is that they can currently only operate continuously for about a day. One reason for this is that optical atomic clocks need to keep many lasers operating in sync in order to work, and over time at least one of these lasers fall out of sync. However,  a key advantage of their network is that it does not require all its clocks to operate at the same time. 

-

February 20, 2022     ATOMIC  CLOCKS  -  finding Dark matter?         3472                                                                                                                                               

----------------------------------------------------------------------------------------

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---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

-----------------------------  Monday, February 21, 2022  ---------------------------