True Shooting Stars;

If you"ve ever gazed up at the night sky (and lets just admit it, we all have) you"ve probably wished upon a shooting star (which are really meteors burning up after entering Earth"s atmosphere) at some point in your life, but shooting stars actually do exist, and they"re as rare as one in 100 million.

In 2005, astronomers discovered the first "hypervelocity" star careening out of the galaxy into intergalactic space at nearly 530 miles per second (or almost 2 million miles per hour), which is 10 times faster than ordinary star movement. They were first theorized to exist in 1988, but not confirmed for several more years. The theory was that binary star systems at a galaxy"s center would occasionally wander too close to the supermassive black hole looming there, which would disrupt their orbital dance. While one of the pair was captured by the black hole, the other would be sent rocketing off at incredible speeds.

One such star, which can be read about here, has a more interesting story: http://www.fromquarkstoquasars.com/true-shooting-stars/

Image Credit: NASA, ESA, and A. Feild (STScI)

Astronomy Picture of the Day: 12/29/13 - PKS 0745-19

Located in a galaxy far, far away in the constellation known as Puppis, lies some of the most massive black holes discovered to date. Some of which, weigh any where from ten to four billion solar masses, effectively reaffirming the long held notion that black holes are strange objects indeed, and there is still much that we don"t understand about them.

PKS 0745 is an elliptical galaxy located approximately 1.3 BILLION light-years from Earth, and it is the central galaxy from a cluster of galaxies known as PKS 0745-19. A survey was conducted with eighteen of the supermassive black holes from PKS 0745, including the black hole at PKS 0745"s galactic center. What they found, is that some of these "ultramassive" black holes are over ten times more massive than previously thought. Interestingly, each "ultramassive" black hole currently discovered lurking at the heart of a galaxy contains an abnormally large quantity of hot gas, which produces diffuse x-ray emissions (pictured here in purple). When these black holes munch on stellar material, cavities are created within the surrounding gas, prohibiting the gas from cooling and collapsing to form new stars.

Optical data (yellow) was provided by the Hubble Space Telescope, with x-rays (purple) coming from the Chandra x-ray observatory. Also used in this composite is radio data from the NSF"s "Very Large Array "(JVLA) and the Australia Telescope Compact Array (ATCA). Infrared data came from the 2 Micron All-Sky Survey (2MASS).

References & Further Reading: http://www.fromquarkstoquasars.com/apod-pks-0745/

Image Credit: X-ray: NASA/CXC/Stanford/Hlavacek-Larrondo, J. et al; Optical: NASA/STScI; Radio: NSF/NRAO/VLA

How are stars born? How do they die?

You’ve probably been told that staring directly at the Sun is bad for your eyes. However, we don’t have to have uncomfortable staring contests with the Stars to try and get them to give up their secrets! After years and years of research, scientists have managed to find out quite a bit about the oh-so-secretive stars without losing a staring contest.

Firstly, stars go through the same process that we do in the sense that they are born, live, and then die. The difference is that they do it far more dramatically, and take a much longer time doing it. Depending on the mass of the star, the lifetime can range from a few million years to trillions of years! So let"s take a moment to get to know a little something about the lives of some of the oldest inhabitants of the universe: STARS.

Learn about the lives of stars at:
http://www.fromquarkstoquasars.com/how-are-stars-born-how-do-they-die/

Image:
NASA

The Formation of Stellar Mass Black Holes: Making energetic destroyers

The formation of a stellar mass black hole is a very chaotic and energetic event. Really though, there isn"t much that involves black holes that isn"t chaotic or energetic. Stellar mass black holes have a minimum mass of around 3.2 times that of our sun (3.2 solar masses). I say "around" because, due to our lack of understanding of neutron degeneracy thresholds, we don"t quite know where the boundary is between neutron stars and black holes. At the moment, 3.2 solar masses is a good guesstimate, as it fits snugly in between the most massive neutron star and smallest black hole ever discovered.

There are three processes that can form a stellar mass black hole; each one is amazing in its own right. Today, we are going to look at comic collisions and epic mergers, and how these processes contribute to the birth of the most destructive objects in the known universe.

Let’s take a look:
http://www.fromquarkstoquasars.com/formation-of-stellar-mass-black-holes-mergers/

Image:
NASA

The Center of a Black Hole: Infinitely Massive Singularity or Portal into another Universe?

Black holes are one of the most naggingly peculiar objects in the universe. Beyond the event horizon of a black hole, our equations are turned upside down; they also get turned inside out when we attempt to fathom the singularity at its center when using the equations given to us by Einstein. To make life simpler, what if we removed the singularity all together? There is some math for that.

Coming full circle, it suggests that black holes do not hold singularities in their interior, but portals to another universe.

Say what?: http://www.fromquarkstoquasars.com/the-center-of-a-black-hole-infinitely-massive-singularity-or-portal-into-another-universe/

Image Credit: mondolithic.com

The Progenitors of Gamma-Ray Bursts:

As we"ve discussed a lot recently, gamma ray bursts have the tendency to be just as spectacular as supernova blasts, with none of the glory. Yet comparatively, our amount of knowledge about them remains decidedly small. Especially so when dealing with how they form. The firsts of these high energy events were brought to our attention by the Vela-5B Satellite in the early 1970"s. At the time of their discovery, we had a difficult time pinpointing their origin, but over the course of the next few years, we were successful in determining that the events were non-local (meaning, they didn"t originated in, or around the sun). Eventually, it was thought that the detected gamma ray-bursts, or GRBs (what these events were eventually called) had a luminosity of about 10^39 ergs, we now know that this is ~13 magnitudes smaller than the actual intensity. Due to the much lower assumed intensity value, astronomers came to the conclusion that the GRB"s may take place in the accretion disk around a collapsing star.

It"s never THAT easy though. Is it? See how our views have changed over the years: http://www.fromquarkstoquasars.com/the-progenitors-of-gamma-ray-bursts/

Image Credit: NASA (Unedited Version: http://ow.ly/rP9EY)

The Progenitors of Gamma-Ray Bursts:

As we"ve discussed a lot recently, gamma ray bursts have the tendency to be just as spectacular as supernova blasts, with none of the glory. Yet comparatively, our amount of knowledge about them remains decidedly small. Especially so when dealing with how they form. The firsts of these high energy events were brought to our attention by the Vela-5B Satellite in the early 1970"s. At the time of their discovery, we had a difficult time pinpointing their origin, but over the course of the next few years, we were successful in determining that the events were non-local (meaning, they didn"t originated in, or around the sun). Eventually, it was thought that the detected gamma ray-bursts, or GRBs (what these events were eventually called) had a luminosity of about 10^39 ergs, we now know that this is ~13 magnitudes smaller than the actual intensity. Due to the much lower assumed intensity value, astronomers came to the conclusion that the GRB"s may take place in the accretion disk around a collapsing star.

It"s never THAT easy though. Is it? See how our views have changed over the years: http://www.fromquarkstoquasars.com/?p=11511

Image Credit: NASA (Unedited Version: http://ow.ly/rP9EY)

The Progenitors of Gamma-Ray Bursts:

As we"ve discussed a lot recently, gamma ray bursts have the tendency to be just as spectacular as supernova blasts, with none of the glory. Yet comparatively, our amount of knowledge about them remains decidedly small. Especially so when dealing with how they form. The firsts of these high energy events were brought to our attention by the Vela-5B Satellite in the early 1970"s. At the time of their discovery, we had a difficult time pinpointing their origin, but over the course of the next few years, we were successful in determining that the events were non-local (meaning, they didn"t originated in, or around the sun). Eventually, it was thought that the detected gamma ray-bursts, or GRBs (what these events were eventually called) had a luminosity of about 10^39 ergs, we now know that this is ~13 magnitudes smaller than the actual intensity. Due to the much lower assumed intensity value, astronomers came to the conclusion that the GRB"s may take place in the accretion disk around a collapsing star.

It"s never THAT easy though. Is it? See how our views have changed over the years: http://www.fromquarkstoquasars.com/?p=11511

Image Credit: NASA (Unedited Version: http://ow.ly/rP9EY)

The Progenitors of Gamma-Ray Bursts:

As we"ve discussed a lot recently, gamma ray bursts have the tendency to be just as spectacular as supernova blasts, with none of the glory. Yet comparatively, our amount of knowledge about them remains decidedly small. Especially so when dealing with how they form. The firsts of these high energy events were brought to our attention by the Vela-5B Satellite in the early 1970"s. At the time of their discovery, we had a difficult time pinpointing their origin, but over the course of the next few years, we were successful in determining that the events were non-local (meaning, they didn"t originated in, or around the sun). Eventually, it was thought that the detected gamma ray-bursts, or GRBs (what these events were eventually called) had a luminosity of about 10^39 ergs, we now know that this is ~13 magnitudes smaller than the actual intensity. Due to the much lower assumed intensity value, astronomers came to the conclusion that the GRB"s may take place in the accretion disk around a collapsing star.

It"s never THAT easy though. Is it? See how our views have changed over the years: http://www.fromquarkstoquasars.com/?p=11511

Image Credit: NASA (Unedited Version: http://ow.ly/rP9EY)

One of the Largest Structures in the Universe:

Astronomers recently discovered a group of active galactic cores that stretch more than 4 billion light-years end to end. The structure is a large quasar group (LQG). And it is simply massive.



For comparison, the Milky Way is about 100,000 light-years across. Our closest neighboring galaxy (Andromeda) is some 2.5 million light-years distant, and it is more than twice the size of the Milky Way (about 260,000 light-years). Which means that this LQG could easily swallow Andromeda, the Milky Way, and all the space in between.

Learn more about this amazing structure and how is impacts the cosmological principle at:
http://www.fromquarkstoquasars.com/largest-structure-in-the-universe-discovered/

Image source:
NARO

The Study of Gamma Ray Bursts (part II)

In a previous article, we discussed the first two major telescopes that were used to study gamma ray bursts (GMBs). These two were the Vela satellites and the Compton Gamma Ray Observatory (CGRO). There was a significant gap between the creation of CRGO and the creation of its successor --BeppoSAX . Ultimately, two decades passed before BepooSAX was created, but despite the rather long time frame between these two observatories, both were an integral part of the future of space telescopes. Tsvi Piran, an astrophysicist who has been at the forefront of gamma-ray burst physics for several decades, describes CGRO as being the "First Revolution" and BeppoSAX as the "Second Revolution."

To learn all about these amazing telescopes and what they did for gamma ray astronomy, see:
http://www.fromquarkstoquasars.com/grb-part-2/

Image source:
NASA

Birth of the Black Hole Witnessed: A “Rosetta Stone Event” for Astronomy

Chances are, all of us know a little something about black holes. They are said to be the vacuum cleaners of the universe (the *very powerful* vacuum cleaners of the universe). They consume asteroids, stars, and entire solar systems. As such, they stand as a kind of sublime horror – the mind is drawn to, and simultaneously recoils from, the awesomeness of these vast cosmological structures. However, despite their grandeur, they are exceedingly difficult to study. But things are changing…

This week scientists saw a gamma ray burst that is more powerful than what many thought was theoretically possible. This event has been dubbed GRB 130427A, and researchers believe that they observed the collapse of a giant star and the birth of a black hole.

Read about this first ever observation at:
http://www.fromquarkstoquasars.com/birth-of-the-black-hole-witnessed-a-rosetta-stone-event-for-astronomy/

Image source: NASA
http://www.nasa.gov/mission_pages/GLAST/science/gammay_ray_bursts.html

Astronomy Picture of the Day: 11/26/13 - Hercules A; Making the Unseen Seen

This is the elliptical galaxy known as Hercules A (formally designated as 3C 348). Other than being visually stunning, this galaxy is notable because it emits nearly a billion times more radio waves than our sun does, making it one of the brightest radio-emitting objects in the constellation of Hercules.

The super-massive black hole that lies at the heart of Hercules A, which is more than 2 billion light-years away, is responsible for manufacturing the spectacular jets seen here. Suffice to say, the black hole is powerful and quite massive, as is the galaxy in general. Compared to the Milky Way, it"s 1,000 times more massive -- with its central black-hole containing the mass of 2.5 billion suns (this makes it approximately 1,000 times massive than the black-hole in the center of our galaxy, Sagittarius A*)

This image is a composite, showing Hercules A in optical light from the Hubble Space telescope"s Wide Field Camera 3, and the recently upgraded Karl G. Jansky Very Large Array (VLA) radio telescope. The VLA revealed the enormous jets that are typically invisible when viewed at optical wavelengths. They are composed of high-energy plasma beam, capable of shooting superheated material off into interstellar space at speeds close to the speed of light. The jets extend almost 1.5 million light-years in width and are only visible using special filters, but this image portrays how they would look if we could see them.

References & Further Reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-112613-hercules-a-making-the-unseen-seen/

Image Credit: NASA, ESA, S. Baum and C. O"Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA)

Astronomy Picture of the Day: 11/20/13 - The Cartwheel Galaxy

There is no doubt that this is one of the most stunningly beautiful galaxies in the observable universe. This, ladies and gentlemen, is a lenticular galaxy named the "cartwheel galaxy" (which tends to look more like a Ferris wheel to my eyes, but whatever). It"s located about 400 million light-years away from Earth in the constellation of Sculptor.

This image is a false-colored composite, put together using 4 separate images taken of the region at various wavelengths. Infrared data was collected by the Spitzer Space Telescope (seen in red), ultraviolet data came from the now-defunct "Galaxy Evolution Explorer" [GALEX] (pictured in blue), x-ray information was derived from the Chandra X-ray Observatory (purple) and visible light data was gathered by the Hubble Space Telescope. The galaxy likely gets its rather unique shape from a collision with a smaller galaxy that took place several hundreds of millions of years ago.

Prior to the collision, the galaxy was probably a spiral galaxy. After the collision took place, the galaxy underwent ferocious cycles of star formation. As you can see, the outer bounds of the galaxy"s rim has several hundreds of thousands of low-mass blue stars that live short lives, before exploding as beautiful supernovae blasts -- leaving behind dense stellar cores, called neutron stars (other times, stellar-mass black holes are created).

The diameter of the galaxy is about 50,000 light-years larger than our home galaxy, the Milky Way. This particular galaxy emits a large amount of infrared energy and x-ray radiation, likely due to the unusually high number of black holes located there. Many of which have a neighboring companion star, which they cannibalize on - releasing x-rays as a result. The "spokes" connecting the outer rim of the galaxy to the central core are non-thermal radio and optical spokes.

Sources & Further Reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-112013-the-cartwheel-galaxy/

Image Credit: Composite: NASA/JPL/Caltech/P.Appleton et al. X-ray: NASA/CXC/A.Wolter & G.Trinchieri et al.

Black Holes: So You *CAN* Divide By Zero

“Black holes are where God (or the Flying Spaghetti monster, maybe) divided by zero.” That has to be one of my favorite math/science jokes. Surprisingly enough, weird things do happen to our equations when you work inside the event horizon of black holes – such as dividing everything by zero. So, other than being the source of a great joke, what are black holes?

Black_Hole_in_the_universeTechnically, a black hole is a region of spacetime where, by nature of its great mass, gravity prevents anything from escaping; this includes light. The term ‘black hole’ was coined by Dr. John Archibald Wheeler during his work in general relativity on gravitational collapse. However, Dr. Wheeler wasn’t the first person to hypothesize a black hole. Einstein wasn’t the first person to think up this phenomena either (even though his equations gave rise to the possibility). Rather, in the 18th century, John Michell and Pierre-Simon Laplace were the first to consider massive objects with gravity fields so great that even light couldn’t escape

Learn more about black holes and how they were discovered at:
http://www.fromquarkstoquasars.com/black-holes-so-you-can-divide-by-zero/

Image source:
http://www.huffingtonpost.com/2013/04/08/black-hole-firewall-theory-paradox-einstein-equivalence_n_3036733.html

The Gravastar: An Alternative to Black Holes?

Today, we thought that we would take a look at an alternative model for black holes. Personally, I"m not that fond of the idea in relation to it"s scientific validity, but I do think it is a very interesting hypothesis. Most of the time, we"re quite content to just sit back and follow the popular mindset in relation to scientific hypotheses and theories. Following the crowd and ignoring many of the "stranger" ideas that go against the norm is one way to ensure that you don"t look foolish; however, it is also one way to ensure that you remain stagnant. At the very least, we must be open to questioning. After all, that is what science is all about.

Nonetheless, we often cling to the tried and true. And this isn"t a recent trend; it is the way that we"ve been all through human history. For example, for many years, we believed that the Earth was flat and that one could eventually fall off of the globe. We also believed that the Earth was the center of the universe (some people still do). And several ancient civilizations even used to use mercury as a medicine. Fortunately, we tested these ideas and came up with better ones.

Which brings us to the Gravastar, an unconventional idea that is as interesting as it is odd. This hypothesis was originally put forward by Mazur and Mottola in 2004. Gravastar literally means "Gravitational Vacuum Condensate Star," which is (in theory) an extension of the Bose-Einstein Condensate and put forward as a part of gravitational systems. Ultimately, it is meant to stand as an alternative to black holes.

To read the full article, see: http://www.fromquarkstoquasars.com/the-gravastar-an-alternative-to-black-holes/

Image source:
NASA