A couple of weeks ago, the ESO announced that they had discovered rings around an asteroid.  They observed an occultation of starlight during Chariklo 10199’s passing, and the resulting light curve was symmetrical and indicative of a double ring system.  Chariklo is small and not perfectly spherical.  It was discovered in 1997, but this has been the first oppurtunity to image it.  It is small enough that it’s escape velocity could be attained by a fast car(350km/s).  The mechanism by which is gained rings is as yet unknown.  It is possible that a collision with another object released debris into orbit.  Prior to the discovery of the rings, a spectral signature for water ice was detected, and it is now thought that ice and dust in the rings are responsible.  In the future a search may continue for shepherd moons or other small satellites that may be associated with the rings.

At 248 km in diameter, it is the largest Centaur yet discovered. Centaurs are a special class of small object in our solar system that cross orbit with the giant planets.  They are not expected to keep these orbits.  They remain stable for estimated times on the order of millions of years before a gravitational interaction with one of the giant planets, or less probably, a collision disturbs their orbit.  Chariklo is very near to 4:3 resonance with Uranus, and so it’s orbit is relatively stable as compared to other centaurs.

http://www.eso.org/public/news/eso1410/

Jewitt; Brown (2001-04-17). “Infrared Observations of Centaur 10119 Chariklo with possible surface variation”. Retrieved 2006-11-09.

“JPL Small-Body Database Browser: 10199 Chariklo (1997 CU26)”. 2008-07-03. Retrieved 2008-10-21.

Braga-Ribas, F.; Sicardy, B.; Ortiz, J. L.; Snodgrass, C.; Roques, F.; Vieira-Martins, R.; Camargo, J. I. B.; Assafin, M.; Duffard, R.; Jehin, E.; Pollock, J.; Leiva, R.; Emilio, M.; Machado, D. I.; Colazo, C.; Lellouch, E.; Skottfelt, J.; Gillon, M.; Ligier, N.; Maquet, L.; Benedetti-Rossi, G.; Gomes, A. R.; Kervella, P.; Monteiro, H.; Sfair, R.; Moutamid, M. E.; Tancredi, G.; Spagnotto, J.; Maury, A. et al. (2014). “A ring system detected around the Centaur (10199) Chariklo”. Nature 508 (7494): 72. doi:10.1038/nature13155. edit

A visual color coded image of the plasma energy distribution inside a supernova (left) and a white dwarf at the moment of detonation shoots out a initial plume. (right)

Physicists recently created more sophisticated computer modeling for supernovas in order to understand the 3 dimensional complexities of such an event. Previous theory and modeling relied on slower computers that generated three dimensional models only by making assumptions of symmetry for one or two directions, thus giving them a less detailed full picture of supernovas. Original simplified theory believed that a massive star’s structure prior to supernova was composed concentric spherical shells made up of heavier elements as one goes deeper into the star. When gravitational collapse first starts, right as nuclear fuel is running out, the star starts to emit large amounts of energy in the form of neutrinos weakly interacting particles due to the compression of the core causing temperature increase. As the core heats up more, this generates more neutrinos and eventually leads to a complete explosion of the envelope of the star leaving behind only a remnant of gas filled with heavy elements and possibly a white dwarf, neutron star, or black hole.

What this new super computer modeling at Argonne National Laboratory shows is that although this theory is true of concentric layers, convection and mixing occurs between layers and increases at the onset of a supernova, leading the star to pulsate and ‘flop,’ creating ejections of heavier material creating instability before the actual supernova explosion. This new theory explains a lot of experimental data on real supernovas, such SN1987A, where we see exactly this phenomenon; Heavy metal material is being ejected before the supernova occurred and then new debris during the explosion is ejected at much faster speeds and catching up with the material. Computer Modeling of this caliber is what is needed to understand the minor details and complexities of stellar evolution, especially for events as dramatic and quick as a supernova.

Sources:

http://news.discovery.com/space/simulation-gives-new-gimpse-into-supernovas-chaotic-guts-140319.htm

Modern Astrophysics 2nd Edition by Carroll Ostlie

Generally, when astronomers and astronauts and all various sorts of scientists who are looking for habitable living spaces, we look for those that imitate Earth in some meaningful way. We want potential living candidates to have comparable revolution periods, temperatures, day length, and overall be as comfortable as our current living conditions.

According to physicists at the University of Texas at Arlington, F-type stars may “indeed be a good place to look for habitable planets.” This comment in itself strikes an alarm bell due to its unusual nature, as F-type stars tend to be in the middle of the stellar scale, and are more massive and hot than the Sun, certainly not a livable habitat. On top of these already non-bearable for human characteristics, F-type stars also emit much more ultraviolet radiation, which could also sustain life heavily.

All in all, the researchers decided to take this bold stance on the issue due to the overall lack of knowledge on the issue, which leads us unable to fight back without doing extensive research to the topic which could simultaneously benefit or hurt either side. What is also postulated is that due to the lack of knowledge on the issue, that there is a much wider habitality range in F-type stars as opposed to other stars or planets. It is always interesting to take a stance that suggests that we look not for answers, but to find more knowledge, which leads us to more questions and yet to more to study, with more depth and more fervor. It would be interesting to hope this is the case because if so, we may find more habitats in our world, on other campuses, and in space. This would open up infinitely more moral questions as to who deserves to live in space, as well as the inherent race separation that would arise from living or separating off into distinct groups in space. However, this is the case with any real technological developments, and dreaming that we are ever free from moral decisions is an illusion at best.

Source:

http://www.sciencedaily.com/releases/2014/03/140325133544.htm

White dwarves come about when Sun-like stars run out of fuel to keep their own thermal energy maintained, collapsing and allowing for a star that has immensely large density, as it retains Sun-like masses for radii that are similar to the Earth’s. In theory, this is fairly simple to understand and process as a means to follow the evolution of certain stars. In stars, however, the fusion processes that allow energy to be generated and exist generally involve relatively few elements worth noting, generally simply hydrogen and helium. White dwarves, even if they were hot, for some reason, even if classified as pure hydrogen or helium, had always been contaminated with other elements that have drawn scientists crazy in an attempt to understand how.

Now, it has been speculated and seen that such elements are the result of planetary debris, the contamination of planetary systems that leave behind rocky material that form such diverse element groups within white dwarves that would normally never include such elements. Using the Far Ultraviolet Spectroscopic Explorer telescope, researchers could discern the spectra and thus determine which elements remained inside these white dwarves. What is fascinating about these means of contamination that allow for this diversity in elements remained a mystery because there was no consistency as to how certain elements ended up on these white dwarves, leading to vast differences in the abundance of specific elements. These stars bear a stark similarity to rocky material in general, as stars or interstellar gases generally lack these compositions.

As the researchers end the same discoveries, we can only assume that this means good progress and good discoveries are on their ways in a world where we have spent almost 20 years discovering this, this leads us to be able to project future white dwarves and their behavior. One particularly scary example I’ll leave you with for the future is the Sun. When the Sun becomes a white dwarf, its fate will be “ending up as merely contamination within the white dwarf remnant of our Sun.”

Source:

http://www.sciencedaily.com/releases/2014/03/140326092240.htm

In the way we examine space, we have spent an enormous amount of time in this class focusing on stars of all varieties and their properties. The varieties in such stars include white dwarves, supergiants, neutron stars, among many others in the list of stellar evolution and in general existence. Rarely, if ever, do we find combinations of stars that result in stars that share multiple properties or reflect different varieties of star within one.

Recent astrophysicists have found that a very real phenomena exists where these stars may be able to be pinpointed as a star on the stellar map, particularly one known as the “Thorne-Zytkow object,” which shares the properties of a red supergiant star and a superdense neutron star. While these have been theorized in 1975 and many stars from then on have been speculated as having existed by observation, in January, the strongest example of one has shown up by an astronomer in Boulder. These stars are fascinating in that they are a result of a collision between these two stars, to the point where the fusion process inside of the red supergiant is interrupted due to the neutron star being “eaten” and settling inside the core of the supergiant, which would also result in a very specific chemical composition due to the massive shift in fusion processes that would result in not only a combination of the elements inside both the red supergiant and the neutron star, but also the new processes that exist to generate energy in this new creation. In this one in particular, there is a high existence of lithium, rubidium, and molybdenum.

What’s left to question after this existence has been theorized is naturally the collision and creation of other hybrid stars that would vastly alter the chemical processes and compositions of stars, as well as the way their generate energy and how such stars would form – questions for us to postulate and for scientists to attempt to solve.

Source:

http://news.discovery.com/space/astronomy/has-the-weirdest-star-in-the-universe-been-discovered-140107.htm

Black holes by very definition and by their very conception by Einstein are defined heavily by their infinitely dense, no volume, singularities that lies in their centers that creates many mass-based gravitational effects on anything around them and anything that dare cross their paths. Such a prominent effect even has a large section of description in the book about what precisely an indestructible astronaut would feel like being put through it and the insane effects this produces on all matter around the singularity.

However, a combination of scientists from University of the Republic in Uruguay and LSU have found that applying the effects of loop quantum gravity, a form of gravity we as students know little to nothing about, but many in the field know extensively about, can result in a conception of a black hole that does not result in these chilling, stretching, annihilating effects, but rather result in a black hole that would lead through to another location in the universe, another location in space (very much wormhole-like). Why is it that we question this construction now? As many of the scientists working to resolve this problem have noted, black holes have always been shrouded in mystery, and a particularly telling component results in the singularity occurring and the immediate breakdown of physics, as we just assume that whatever passes through the black hole is utterly annihilated, spaghettified, and equations stop mattering, in a sense.

This relates heavily back to cosmology as the Big Bang is thought to have started with a singularity, and helps identify its loop quantum gravity’s own methodology to define how these functions work. Gravity would still be strong and strengthen as you approached the center of the black hole, but would eventually lead to a spacetime jump, the stuff of science fiction and legend. The more we learn about physics, the more everyone hopes a little to find a little bit of the future in the knowledge.

Sources:

http://scitechdaily.com/study-takes-singularity-out-of-black-holes/

Grand Unified Theory, the idea that all forces can somehow relate to one another and influence one another to the point where we have one set solid explanation of the world and its forms and forces, naturally starts in cosmology, where gravity tends to resist all developments in the area. Gravity itself is a tricky force, generally classified as a “weak” force but having immense effects, depending on mass, to even light, as we learned recently.

However, the gravitational constant that Newton discovered that fundamentally became set in stone as the way to measure gravity and its strength, has previously been thought to have adjusted over time to adjust for the different forces that allowed for the Big Bang to form the universe and for all different varieties of gravity affecting the formation of the universe. Australian astronomers recently, compiling data from 580 different observable supernovae seen and recorded have come to the conclusion that the gravitational constant has been constant in the last 9 billion years! This affects the critical mass at which supernovae form to begin with, as well as altering how we perceive of the past universe – with the former idea of a changing gravitational constant, we could have assumed that the Earth had a larger semimajor axis and experienced different, longer seasons, for example, not as a result of the atmosphere but as a result of distance, or that the universe had formed in different ways that allowed adjusting to happen over time, not simply as a result of what we can already project backwards.

Fortunately or unfortunately, this means that as much as we try to deny Newton and his prowess in many different fields at one, it’s still hard to best someone from the 1600-1700s with modern day technology that gives us a deeper glimpse and further depth of truth into what we search for.

Source:

http://www.sciencedaily.com/releases/2014/03/140324230254.htm

There is an interesting conclusion to be drawn from current theoretical physics, and it goes something like this: If the universe is infinite, but there are a finite number of ways for matter to be arranged, then our Earth, with its exact same history, exists in other places in the universe. Not just a few places, but an infinite number of places. This means there are an infinite number of me and you, with an also infinite number of “alternative” versions of us who branch off and make different decisions every second. Pretty crazy, huh?

There are a few things that need to be clarified in this scenario. First of all, even if the universe is infinite in nature, the observable universe is not. We can only observe the parts of the universe from where light has been able to reach us. This observable universe has a calculable volume. One estimate has taken the volume of the universe and divided by the smallest possible quantum length and concluded that there are “only” about 10^180 unique points in the observable universe. An incomprehensibly huge number, yes, but not infinite. So even if there were copies of us somewhere out there, they would truly be existing in an “alternate” universe, unobservable in every way.

Another issue of late has been the shape of the universe. If it folds over on itself like a sphere, it could have infinite pathways to travel without being infinite in volume. Recently, by observing the nature of the cosmic background radiation, NASA’s WMAP project has concluded that the universe is flat to within 0.4%. This leaves the alternative unobservable universes as a possibility.

There are many characteristics of space that challenge the extent of human imagination, but this takes it to another level. If a resolution to this idea is coming, it may be soon as we learn more about the birth of our universe and the Big Bang.

Astrophysicists believe as of now, that 25% of the matter and energy in our universe is ‘dark’ matter. Although this name sounds flashy, all it means is that this mass can’t be seen with light, like the ‘normal’ illuminated baryonic matter we are made of. Many experiments have been done that confirm dark matter’s indirect existence. The overwhelming evidence for dark matter comes from when one gravitationally analyzes the stars’ orbits and structure within our galaxy. After a complex analysis of several galaxies structure, one is forced to conclude that there is not enough baryonic matter to hold the galaxy together, and that its’ stars will just fly apart, destroying the structure we see. But, the data shows that although the matter we see is not enough to hold the stars together, the galaxies are still forming as if there is a ‘sphere’ of invisible matter dispersed throughout the galaxy and in between the stars. This is the dark matter, and so much of it is needed to hold the gravitational structure we see that there must be more of it than normal baryonic matter

Part of science, however, is finding theory that supports the existence of a new type of matter. Rather than consider this flaw a failure of our theory of gravity, which many physicists think it could be, scientists believe that there must be a theoretical particle that could explain this phenomenon. Its a very similar reasoning scientists took when they discovered the neutrino; rather than refute the laws of conservation of energy and momentum, Wolfgang Pauli proposed a weakly interacting particle that made up for this energy and momentum, and it turned out to actually exist. The best candidate for a dark matter particle as of now is called a WIMP, weakly interacting massive particle, which is similar to a neutrino in that it interacts vey weakly with normal matter, but it is much more massive that a neutrino, thus it is capable of creating the gravitational attraction we observe. Many projects have started that are trying to build WIMP detectors that could detect a WIMP very similar to how we detect neutrinos. Using underground mines and a large tank of xenon or other baryonic atoms that weakly interact with WIMPS, scientists predict how many WIMPS should interact on average with their detector based on how much dark matter passes through the earth all the time, and the signature of the interaction to prove if dark matter is really there. It will be very exciting to see how these experiments pan out.

Sources:

http://www.sciencedaily.com/releases/2014/03/140310212316.htm

http://en.wikipedia.org/wiki/Dark_matter

http://en.wikipedia.org/wiki/Neutrino

Scientists studying the atmosphere’s of White Dwarfs made an interesting announcement recently. After studying the spectra of hot young white dwarfs, scientists from the University of Leicester and the University of Arizona can now speak  more closely to the atmospheres of these objects. For those who are not aware, White Dwarfs are the remnants of Sun like stars. The are comprised of a core of oxygen, nitrogen, and carbon, the byproducts of hydrogen and helium fusion during their lifetime on the main sequence. The core then collapses, to about the size of the Earth, and what is left is a dense core of metals(and astronomical term for anything thats not hydrogen or helium) and a think atmosphere still comprised of hydrogen and helium. But the spectra of these exotic stars atmospheres had led to something strange. Higher contents of metals were observed in the atmosphere than what was expected. Was this due to some convective force bringing up material from the White Dwarf’s core, or was there some other source for the metals being observed in the atmosphere. 

According to the new research. It turns out that the source of these metals seem to be rocky planets. The levels of Carbon, Silicon, and Iron detected is exactly what you would expect if the star was absorbing earth like planets, and it seems that is indeed what they are doing. This discovery not only leaves us with an interesting end game for earth, but also provides us with a new tool for the fate of the earth. According to most calculations anyway, the earth will be destroyed by the Sun long before the Sun becomes a White Dwarf, but whether our precious metals stick around in the Sun’s atmosphere is a topic of debate. This discovery however, allows us to study the composition of extrasolar rocky planets like we have never before. Rocky planets as we now know are very common in the universe, but they are so small that it is hard to confirm their existence in faraway galaxies. Even after detecting them, knowing their composition is an entirely different matter. Stars compositions have long been studied using their spectra, or certain wavelengths of light that are absorbed and emitted from elements switching through energy states, but for rocky planets, this is impossible. First, no one has directly imaged a terrestrial exoplanet, and even if you could, you probably wouldn’t see much besides atmospheric spectra. Now by studying the atmosphere of white dwarfs, fairly common in the Galaxy, we can now tell the internal compositions of faraway terrestrial planets, which in turn allows us to compare with our own terrestrial planets and further our understanding of Solar Systems and the planets inside them.

http://www.sciencedaily.com/releases/2014/03/140326092240.htm