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Astrophysics - Blog Posts
Newton's Laws of Motion
1) "An object will not change its motion unless acted on by an unbalanced force."
A body remains at rest, or in motion at a constant speed in a straight line, except insofar as it is acted upon by a force.
2) "Force equals mass multiplied by acceleration."
The net force on a body is equal to the body's acceleration multiplied by its mass or, equivalently, the rate at which the body's momentum changes with time.
3) "Every action has an equal and opposite reaction"
If two bodies exert forces on each other, these forces have the same magnitude but opposite directions.
Jupiter
Make way for the king of the solar system! 👑
New Webb images of Jupiter highlight the planet’s features, including its turbulent Great Red Spot (shown in white here), in amazing detail. These images were processed by citizen scientist Judy Schmid.
"I look up at the night sky, and I know that, yes, we are part of this Universe, we are in this Universe, but perhaps more important than both of those facts is that the Universe is in us. When I reflect on that fact, I look up. Many people feel small, because they’re small and the Universe is big. But I feel big, because my atoms came from those stars."
- Neil deGrasse Tyson
Astronomy/Astrophysics >>>>>>>>>>>
I made this black and white astronaut art but I’m not sure if I should color it, this was made about 5 months ago I think
Webb + Hubble > peanut butter + chocolate? We think so!
In this image of galaxy cluster MACS0416, the Hubble and James Webb space telescopes have united to create one of the most colorful views of the universe ever taken. Their combination of visible and infrared light yields vivid colors that give clues to the distances of galaxies (blue = close, red = far).
Looking at the combined data, scientists have spotted a sprinkling of sources that vary over time, including highly magnified supernovas and even individual stars billions of light-years away.
Credit: NASA, ESA, CSA, STScI, J. Diego (Instituto de Fisica de Cantabria, Spain), J. D’Silva (U. Western Australia), A. Koekemoer (STScI), J. Summers & R. Windhorst (ASU), and H. Yan (U. Missouri).
ALT TEXT: A field of galaxies on the black background of space. In the middle, stretching from left to right, is a collection of dozens of yellowish spiral and elliptical galaxies that form a foreground galaxy cluster. They form a rough, flat line along the center. Among them are distorted linear features, which mostly appear to follow invisible concentric circles curving around the center of the image. The linear features are created when the light of a background galaxy is bent and magnified through gravitational lensing. At center left, a particularly prominent example stretches vertically about three times the length of a nearby galaxy. A variety of brightly colored, red and blue galaxies of various shapes are scattered across the image, making it feel densely populated. Near the center are two tiny galaxies compared to the galaxy cluster: a very red edge-on spiral and a very blue face-on spiral, which provide a striking color contrast.
Different Types of Supernovae are the Primary Origins of Different Classes of Chemical_Elements.
You Are Made of Stardust
Though the billions of people on Earth may come from different areas, we share a common heritage: we are all made of stardust! From the carbon in our DNA to the calcium in our bones, nearly all of the elements in our bodies were forged in the fiery hearts and death throes of stars.
The building blocks for humans, and even our planet, wouldn’t exist if it weren’t for stars. If we could rewind the universe back almost to the very beginning, we would just see a sea of hydrogen, helium, and a tiny bit of lithium.
The first generation of stars formed from this material. There’s so much heat and pressure in a star’s core that they can fuse atoms together, forming new elements. Our DNA is made up of carbon, hydrogen, oxygen, nitrogen, and phosphorus. All those elements (except hydrogen, which has existed since shortly after the big bang) are made by stars and released into the cosmos when the stars die.
Each star comes with a limited fuel supply. When a medium-mass star runs out of fuel, it will swell up and shrug off its outer layers. Only a small, hot core called a white dwarf is left behind. The star’s cast-off debris includes elements like carbon and nitrogen. It expands out into the cosmos, possibly destined to be recycled into later generations of stars and planets. New life may be born from the ashes of stars.
Massive stars are doomed to a more violent fate. For most of their lives, stars are balanced between the outward pressure created by nuclear fusion and the inward pull of gravity. When a massive star runs out of fuel and its nuclear processes die down, it completely throws the star out of balance. The result? An explosion!
Supernova explosions create such intense conditions that even more elements can form. The oxygen we breathe and essential minerals like magnesium and potassium are flung into space by these supernovas.
Supernovas can also occur another way in binary, or double-star, systems. When a white dwarf steals material from its companion, it can throw everything off balance too and lead to another kind of cataclysmic supernova. Our Nancy Grace Roman Space Telescope will study these stellar explosions to figure out what’s speeding up the universe’s expansion.
This kind of explosion creates calcium – the mineral we need most in our bodies – and trace minerals that we only need a little of, like zinc and manganese. It also produces iron, which is found in our blood and also makes up the bulk of our planet’s mass!
A supernova will either leave behind a black hole or a neutron star – the superdense core of an exploded star. When two neutron stars collide, it showers the cosmos in elements like silver, gold, iodine, uranium, and plutonium.
Some elements only come from stars indirectly. Cosmic rays are nuclei (the central parts of atoms) that have been boosted to high speed by the most energetic events in the universe. When they collide with atoms, the impact can break them apart, forming simpler elements. That’s how we get boron and beryllium – from breaking star-made atoms into smaller ones.
Half a dozen other elements are created by radioactive decay. Some elements are radioactive, which means their nuclei are unstable. They naturally break down to form simpler elements by emitting radiation and particles. That’s how we get elements like radium. The rest are made by humans in labs by slamming atoms of lighter elements together at super high speeds to form heavier ones. We can fuse together elements made by stars to create exotic, short-lived elements like seaborgium and einsteinium.
From some of the most cataclysmic events in the cosmos comes all of the beauty we see here on Earth. Life, and even our planet, wouldn’t have formed without them! But we still have lots of questions about these stellar factories.
In 2006, our Stardust spacecraft returned to Earth containing tiny particles of interstellar dust that originated in distant stars, light-years away – the first star dust to ever be collected from space and returned for study. You can help us identify and study the composition of these tiny, elusive particles through our Stardust@Home Citizen Science project.
Our upcoming Roman Space Telescope will help us learn more about how elements were created and distributed throughout galaxies, all while exploring many other cosmic questions. Learn more about the exciting science this mission will investigate on Twitter and Facebook.
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The Astronomical Discovery of BUCKYBALLS in The Small Magellanic Cloud back in The_Year of 2010.
December 17th of 2019 is The Launch Date of The CHEOPS_Mission to measure The Radii of EXOPLANETS Which have already been discovered by now.
This is The Smallest Sized EXOPLANET Discovered by NASA's TRANSITING EXOPLANET SURVEY SATELLITE so far!
NASA's TESS mission finds its smallest planet yet
NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered a world between the sizes of Mars and Earth orbiting a bright, cool, nearby star. The planet, called L 98-59b, marks the tiniest discovered by TESS to date.
Two other worlds orbit the same star. While all three planets’ sizes are known, further study with other telescopes will be needed to determine if they have atmospheres and, if so, which gases are present. The L 98-59 worlds nearly double the number of small exoplanets – that is, planets beyond our solar system – that have the best potential for this kind of follow-up.
“The discovery is a great engineering and scientific accomplishment for TESS,” said Veselin Kostov, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the SETI Institute in Mountain View, California. “For atmospheric studies of small planets, you need short orbits around bright stars, but such planets are difficult to detect. This system has the potential for fascinating future studies.”
A paper on the findings, led by Kostov, was published in the June 27 issue of The Astronomical Journal.
Keep reading
This could be The First Confirmed Astronomical Discovery of an Extrasolar_Moon more than 20_Years after The First Confirmed Astronomical Discovery of an Extrasolar_Planet was made!
I wonder what Alien Lifeforms which have evolved on Habitable_Zone Moons and Habitable_Zone Planets in Other Solar_Systems would look like?
Life in The TRAPPIST_1 System
The Potential for Life is higher than ever on The TRAPPIST_1 Exoplanets, a Researcher says. http://wr.al/1AePv
Nearby Exoplanet is 'excellent' target in The Search for Life.
Spectroscopic Observations of The Atmospheres and possibly even The Surfaces of Extrasolar Planets and Extrasolar Satellites.
ESA’s next science mission to focus on nature of exoplanets
The nature of planets orbiting stars in other systems will be the focus for ESA’s fourth medium-class science mission, to be launched in mid 2028.
Ariel, the Atmospheric Remote‐sensing Infrared Exoplanet Large‐survey mission, was selected by ESA today as part of its Cosmic Vision plan.
The mission addresses one of the key themes of Cosmic Vision: What are the conditions for planet formation and the emergence of life?
Thousands of exoplanets have already been discovered with a huge range of masses, sizes and orbits, but there is no apparent pattern linking these characteristics to the nature of the parent star. In particular, there is a gap in our knowledge of how the planet’s chemistry is linked to the environment where it formed, or whether the type of host star drives the physics and chemistry of the planet’s evolution.
Ariel will address fundamental questions on what exoplanets are made of and how planetary systems form and evolve by investigating the atmospheres of hundreds of planets orbiting different types of stars, enabling the diversity of properties of both individual planets as well as within populations to be assessed.
Observations of these worlds will give insights into the early stages of planetary and atmospheric formation, and their subsequent evolution, in turn contributing to put our own Solar System in context.
“Ariel is a logical next step in exoplanet science, allowing us to progress on key science questions regarding their formation and evolution, while also helping us to understand Earth’s place in the Universe,” says Günther Hasinger, ESA Director of Science.
“Ariel will allow European scientists to maintain competitiveness in this dynamic field. It will build on the experiences and knowledge gained from previous exoplanet missions.”
The mission will focus on warm and hot planets, ranging from super-Earths to gas giants orbiting close to their parent stars, taking advantage of their well-mixed atmospheres to decipher their bulk composition.
Ariel will measure the chemical fingerprints of the atmospheres as the planet crosses in front of its host star, observing the amount of dimming at a precision level of 10–100 parts per million relative to the star.
As well as detecting signs of well-known ingredients such as water vapour, carbon dioxide and methane, it will also be able to measure more exotic metallic compounds, putting the planet in context of the chemical environment of the host star.
For a select number of planets, Ariel will also perform a deep survey of their cloud systems and study seasonal and daily atmospheric variations.
Ariel’s metre-class telescope will operate at visible and infrared wavelengths. It will be launched on ESA’s new Ariane 6 rocket from Europe’s spaceport in Kourou in mid 2028. It will operate from an orbit around the second Lagrange point, L2, 1.5 million kilometres directly ‘behind’ Earth as viewed from the Sun, on an initial four-year mission.
Following its selection by ESA’s Science Programme Committee, the mission will continue into another round of detailed mission study to define the satellite’s design. This would lead to the ‘adoption’ of the mission – presently planned for 2020 – following which an industrial contractor will be selected to build it.
Ariel was chosen from three candidates, competing against the space plasma physics mission Thor (Turbulence Heating ObserveR) and the high-energy astrophysics mission Xipe (X-ray Imaging Polarimetry Explorer).
Solar Orbiter, Euclid and Plato have already been selected as medium-class missions.
At Least 94 More Exoplanets were just recently discovered by Astronomers and Astrophysicists using NASA's Kepler Space_Telescope.
Scientists discover almost 100 new exoplanets
“We started out analyzing 275 candidates of which 149 were validated as real exoplanets. In turn 95 of these planets have proved to be new discoveries,” said American PhD student Andrew Mayo at the National Space Institute (DTU Space) at the Technical University of Denmark.
“This research has been underway since the first K2 data release in 2014.”
Mayo is the main author of the work being presented in the Astronomical Journal.
The research has been conducted partly as a senior project during his undergraduate studies at Harvard College. It has also involved a team of international colleagues from institutions such as NASA, Caltech, UC Berkeley, the University of Copenhagen, and the University of Tokyo.
Keep reading
There is a Planet out beyond Our Solar_System which has a 27,000 Year Long Orbit around it’s Host_Star.
"The Science of Star Wars: An Astrophysicist's Independent Examination of Space Travel, Aliens, Planets, and Robots as Portrayed in the Star Wars Films and Books" by Jeanne Cavelos
The Solar System has at least two more planets waiting to be discovered beyond the orbit of Pluto, Spanish and British astronomers say. Beyond Neptune, Pluto was relegated to the status of "dwarf planet" by the International Astronomical Union in 2006, although it is still championed by some
A Huge_Planet that’s "too big for its Host_Star" has been spotted orbiting a Faint Red_Dwarf Star by some Australian Researchers - with the help of a Backyard Astronomer.
Here’s a Look at Kepler’s Second_Law of Planetary Motion.
This image displays Kepler’s second law of planetary motion.
“A line joining a planet and the Sun sweeps out equal areas during equal intervals of time” (Meaning that each triangle seen there has equal area.)
The black dot represents a planet, the point where the black lines intersect represent the sun.
The green arrow represents the planet’s velocity,
The purple arrows represents the force on the planet.
(Image source: here)
I bet Neil deGrasse Tyson’s wife never made him a really cool, tongue-in-cheek t-shirt. #astronomy #space #astrophysics #neildegrassetyson https://www.instagram.com/p/B3bKmaPnB-W/?igshid=1oj68t0cep4hn
Imagine being this beautiful:
They are the sh*t, and they know it.
I love supermassive black holes!!!
Expect this in the chapter about black holes lol
The relationship between SBHs and their host galaxies are so cool!
WANT MORE? GET YOUR HEAD STUCK IN THE STARS AT MY BLOG!
AAS NOVA
A Young Population of Hidden Jets
By Susanna Kohler
Looking for a fireworks show this 4th of July? Try checking out the distant universe, where powerful jets flung from supermassive black holes slam into their surroundings, lighting up the sky.
Though these jets are hidden behind shrouds of gas and dust, a new study has now revealed some of these young powerhouses.
A Galaxy–Black-Hole Connection
In the turbulent centers of active galaxies (active galactic nuclei, or AGN), gas and dust rains onto supermassive black holes of millions to billions of solar masses, triggering dramatic jets that plow into the surrounding matter and light up across the electromagnetic spectrum.
The growth of a supermassive black hole is thought to be closely tied to the evolution of its host galaxy, and feedback like these jets may provide that link. As the jets collide with the gas and dust surrounding the galaxy’s nucleus, they can trigger a range of effects — from shock waves that drive star formation, to gas removal that quenches star formation.
To better understand the connections between supermassive black holes and their host galaxies, we’d especially like to observe AGN at a time known as Cosmic Noon. This period occurred around 10 billion years ago and marks a time when star formation and supermassive black hole growth was at its strongest.
The Hidden World of Cosmic Noon
But there’s a catch: around Cosmic Noon, galaxies were heavily shrouded in thick gas and dust. This obscuring material makes it difficult for us to observe these systems in short wavelengths like optical and X-ray. Instead, we have to get creative by searching for our targets at other wavelengths.
Since AGN emission is absorbed by the surrounding dust and re-radiated in infrared, we can use infrared brightness to find obscured but luminous sources. To differentiate between hidden clumps of star formation and hidden AGN, we also look for a compact radio source — a signature that points to a jet emitted from a central black hole.
A team of scientists led by Pallavi Patil (University of Virginia and the National Radio Astronomy Observatory) has now gone on the hunt for these hidden sources at Cosmic Noon.
Newly-Triggered Jets Caught in the Act
Patil and collaborators observed a sample of 155 infrared-selected sources, following up with high-resolution imaging from the Jansky Very Large Array to identify compact radio sources. From their observations and modeling of the jets, the authors estimate these sources’ properties.
The authors find bright luminosities, small sizes, and high jet pressures — all of which suggest that we’ve caught newly-triggered jets in a short-lived, unique phase of AGN evolution where the jets are still embedded in the dense gas reservoirs of their hosts. The jets are expanding slowly because they have to work hard to push through the thick clouds of surrounding material. Over time, the jets will likely expand to larger scales and clear out the surrounding matter, causing the sources to evolve into more classical looking radio galaxies.
What’s next? The authors are currently working on a companion study to further explore the shapes of the jets and their immediate environments. These young, hidden sources will provide valuable insight into how supermassive black holes evolve alongside their host galaxies.
Citation “High-resolution VLA Imaging of Obscured Quasars: Young Radio Jets Caught in a Dense ISM,” Pallavi Patil et al 2020 ApJ 896 18. doi:10.3847/1538-4357/ab9011
TOP IMAGE….Artist’s impression of a galaxy forming stars, as powerful jets that are flung from its central black hole collide with the surrounding matter. [ESO/M. Kornmesser]
CENTRE IMAGE….This composite image of Centaurus A shows an example of large-scale jets launched from an AGN, which can eventually extend far beyond the galaxy, as seen here. [ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray)]
LOWER IMAGE….The redshift distribution of the authors’ sample, based on spectroscopic redshifts of 71 sources. The sources span the period of peak star formation and black hole fueling around Cosmic Noon. [Patil et al. 2020]
BOTTOM IMAGE….The JVLA 10 GHz radio continuum observations for four sources in the authors’ sample. The cyan plus symbol marks the infrared-obtained source position. The color bars indicate flux in mJy/beam. [Adapted from Patil et al. 2020]
THE LIFE OF A STAR: WHAT GOES AROUND, COMES AROUND
Previously on The Life of a Star, Chapter 6 ...
"But what happens after the shell is fused? We'll get back to that in Chapter 7, where we'll discuss White Dwarfs and Planetary Nebulae."
After a low-mass star loses its hydrogen core, it becomes a mighty Red Giant - the star contracts and then heats up again, igniting hydrogen shell fusion and swelling the star to epic proportions. That is, until the hydrogen shell and the helium core and all fused up, in which the helium shell will begin to fuse. Remember the last chapter, when I said that these stars don't have enough pressure to fuse the results of the triple-alpha process? Well, I wasn't lying.
And unlike the end of hydrogen fusion - where low-mass stars have a "2nd life" and continue fusing the elements - this means the end for our star. Now, due to the build-up of carbon and oxygen in the core (and the lack of enough pressure to fuse these elements), the star has run out of fuel. This cancels out gas pressure, which breaks the hydrostatic equilibrium. Gravity wins the constant battle within the star, and the core collapses.
The leftover core - tiny and hot - is called a Wolf-Rayet type star and squeezed into a volume one-millionth the size of the original star (Harvard). Now, why does the star stop here? If gravity overpowers the pressure inside the star, why does it not completely collapse into a black hole? Well, that's due to a little thing called electron degeneracy pressure. Basically, the Pauli exclusion principle states that "no two electrons with the same spin can occupy the same energy state in the same volume." Due to the core collapse, electrons are forced together. The Pauli exclusion principle predicts that these electrons, once having filled a lower energy state, will move to a higher one and begin to speed up. This creates pressure and prevents the core from further collapse. However, at a certain mass, this becomes impossible to maintain. White dwarfs have something called the Chandrasekhar limit, which states that white dwarfs cannot exist if their original mass is over 1.44 times the mass of the Sun. This is due to mass-radius relationships, something we'll discuss in the next chapter.
One of my favorite things about stars is the fact that they're a cycle - the death of some stars causes the birth of others. White dwarfs do this, too, by creating something we talked about in Chapter 3: Planetary Nebulae.
The collapsed Wolf-Rayet type star is extremely small, with high density and temperature. Streams of photons/energy/heat - stellar winds - push out the cooler outer layers of the dead star (Astronomy Notes). The core emits UV radiation, which ionizes the hydrogen and causes it to emit light, forming fluorescent and spherical clouds of gas and dust surrounding the hot white dwarf. These are Planetary Nebulae, which can later be clumped by gravity and spun to create a new star. The cycle continues (Uoregon).
The leftover core, the White Dwarf, is characterized by a low luminosity (due to the lack of new photons, which the star will start to lose by radiation) and a mass under about 1.44 times that of the Sun.
Due to the intense gravity, the White Dwarf (despite being very large in mass) has a radius comparable to that of the Earth. If you consult the density equation (d=m/v, which basically means that if you enlarge or shrink either the mass or the volume that the density will increase), White Dwarfs have enormous densities. The core is a compact of carbon and oxygen. Because the star is unable to fuse these elements, they kind of just ... sit there. Surrounding this is a shell of helium and a small hydrogen envelope. Some even have a very thin layer of carbon (Britannica).
However, the White Dwarf isn't the end for the star. There's one more stage for the star to go through before completely "dying": becoming a Black Dwarf.
After the core is left behind, there Is no fuel left to burn. That means no new energy production. However, the leftover heat from the contraction remains, and the star will begin to cool down. Higher mass White Dwarfs, due to having a smaller radius, radiate this away slower than the low-mass ones. There are two types of cooling: radiative and neutrino. Radiative cooling is simple: as the star gives off light and energy outward, it loses heat. Neutrino cooling is a bit more complex: at extremely hot temperatures, gamma radiation passes electrons, and this reaction creates a pair of neutrinos. Because neutrinos interact very weakly with matter, they escape the White Dwarf quickly, taking energy with them. It's also possible to have a hunch of crystal in the center of a Black Dwarf: "On the other hand, as a white dwarf cools, the ions can arrange themselves in an organized lattice structure when their temperature falls below a certain point. This is called crystallization and will release energy that delays the cooling time up to 30%." (Uoregon).
The White Dwarf will become a Black Dwarf after it radiates away all of its heat and becomes a cold, dark shell of its former self. Because it's radiated away all of its heat, it emits no light, hence the name. However, according to theoretical physics, there isn't a single Black Dwarf in the universe. Why? Because it should take at least a hundred million, billion years for a White Dwarf to cool down into a Black Dwarf. Because the universe is predicted to be around 13.7 billion years old, there hasn't been enough time for a single White Dwarf to completely cool down (space.com).
However, there's one last thing that can happen to a White Dwarf. And that's where things in this book will start to get explosive.
White Dwarfs in binary star systems (where two stars orbit around a center of mass, we'll touch on it more in Additional Topics) can undergo a Classical Nova. These supernovae occur in systems with one White Dwarf and one main-sequence star. If they orbit close enough, the White Dwarf will begin to pull the hydrogen and helium from the other star in what is called an Accretion Disk, what is to say a disk of plasma and particles which spiral inwards due to gravity and feeds one body off of another. The accretion of this plasma onto the surface of the White Dwarf increases pressure and temperature so much that fusion reactions spark and the outburst of energy ejects the shell in a burst of light - a nova (Cosmos).
This process doesn't end, however. It can repeat itself again and again in what is called a Recurrent Nova. We know the existence of these based on pictures of the same star system with expanding shells, the aftermath of recurrent novae. Because White Dwarfs are the most common star death in the universe, and most stars are in binary or multiple star systems, novae are fairly common (Uoregon).
Our discussion of novae will be an excellent transition into our next topic: supernovae! This will be the beginning of the end for the High-mass stars we talked about in Chapter 6, and we’ll even talk a little bit more about White Dwarf collisions and how they are related to supernovae, neutron stars, and more!
From here on out, stars are going to become much more dramatic - and all the cooler (well, not really)!
First - Chapter 1: An Introduction
Previous - Chapter 6: The End (But Not Really)
Next - Chapter 8: Why We’re Literally Made of Star-stuff (unpublished)
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Update on The Life of a Star, Chapter 7
So I’m a little over halfway done (I should be ready for some editing on Saturday) with this chapter and I think this might be my one longest yet! My current longest is Chapter 6, with 1,245 words. I’m currently at around 700 words with this one, and I’ve got at least 400 more to go. Anyway, I’m really excited for this one. We’ll be touching on nebulae again, and finally addressing our first ending for a star.
We’ve only got three more chapters left, plus a possible one for additional topics. I’ll be sad to end this one, but I’m starting to gather ideas for the next book. Maybe on the methods of observing the universe? Maybe on random astrophysics topics? Perhaps one on galaxies? Cosmology? The Four Fundamental Forces? Haven’t decided yet xD
I think you’ll all really like these last chapters I have planned, or at least I hope you do. Thanks for reading :)
WANT MORE? GET YOUR HEAD STUCK IN THE STARS AT MY BLOG!