Welcome to Sea and Sky's Cosmology News. Here you can find links to the latest space news headlines about cosmology and astrophysics. Click on any yellow title below to view the full news article. The news article will open in a new browser window. Simply close the browser window when you are finished reading the article to return to the news article listing. You can use the "Click for More" link to go to a page with more news headlines.
|The universe is expanding at an accelerating rate, or is it?|
Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery that the universe is expanding at an accelerating pace. This led to the widespread acceptance of the idea that the universe is dominated by a mysterious substance named 'dark energy' that drives this accelerating expansion. Now, a team of scientists has cast doubt on this standard cosmological concept. The evidence for acceleration may be flimsier than previously thought, they say, with the data being consistent with a constant rate of expansion.
Publ.Date : Fri, 21 Oct 2016 12:32:38 EDT
Astrophysicists map the Milky Way
Hydrogen. Atomic number 1. It is the simplest and lightest element on the periodic table, but don't be fooled by its humble appearance. With just a single proton and a single electron, it is the most abundant element in the universe and has fueled star formation for the past 13 billion years. Now scientists have mapped the key ingredient's distribution across the Milky Way, revealing details about our galaxy that have never been seen before.
Publ.Date : Wed, 19 Oct 2016 18:50:09 EDT
Observable universe contains two trillion galaxies, 10 times more than previously thought
Using data from deep-space surveys taken by NASA's Hubble Space Telescope and other observatories, astronomers have performed a census of the number of galaxies in the universe. The team came to the surprising conclusion that there are at least 10 times as many galaxies in the observable universe than previously thought. The results have clear implications for our understanding of galaxy formation, and also helps shed light on an ancient astronomical paradox -- why is the sky dark at night?
Publ.Date : Thu, 13 Oct 2016 11:17:09 EDT
Dense molecular gas disks drive the growth of supermassive black holes: Are supernova explosions the key?
Astronomers have revealed that dense molecular gas disks a few hundred light years in scale located at the centers of galaxies supply gas to supermassive black holes situated within them. This finding provides important insights on the growth of supermassive black holes over cosmic time.
Publ.Date : Thu, 13 Oct 2016 09:57:52 EDT
Cosmological mystery solved by largest ever map of voids and superclusters
Astrophysicists have created the largest ever map of voids and superclusters in the Universe, which helps solve a long-standing cosmological mystery.
Publ.Date : Wed, 12 Oct 2016 09:58:19 EDT
Using oxygen as a tracer of galactic evolution
A new study casts light on how young, hot stars ionize oxygen in the early universe and the effects on the evolution of galaxies through time. The study presents the first measurements of the changing strengths of oxygen emission lines from the present day and back to 12.5 billion years ago. The main conclusions are that the strength of doubly ionized oxygen increases going back in time, while the strength of singly ionized oxygen increases up to 11 billion years ago and then decreases for the remaining one to two billion years.
Publ.Date : Fri, 07 Oct 2016 09:34:57 EDT
Detonating white dwarfs as supernovae
A new mathematical model created by astrophysicists details a way that dead stars called white dwarfs could detonate, producing a type of explosion that is instrumental to measuring the extreme distances in our universe. The mechanism could improve our understanding of how Type Ia supernovae form.
Publ.Date : Tue, 04 Oct 2016 13:43:10 EDT
Astronomy: Discovery of an extragalactic hot molecular core
Astronomers have discovered a 'hot molecular core,' a cocoon of molecules surrounding a newborn massive star, for the first time outside our Galaxy. The discovery marks the first important step for observational studies of extragalactic hot molecular cores and challenges the hidden chemical diversity of our universe.
Publ.Date : Tue, 04 Oct 2016 11:25:41 EDT
Reconstructing the cosmic history of star formation: ALMA takes stock of the fuel for star formation in distant galaxies
Using the millimeter telescope ALMA, a team of astronomers has traced the raw building blocks of star formation back in time to an era about 2 billion years after the big bang, yielding clues as to the history of star formation in our universe.
Publ.Date : Thu, 29 Sep 2016 14:51:49 EDT
ALMA catches stellar cocoon with curious chemistry: First of its kind to be found outside the Milky Way
A hot and dense mass of complex molecules, cocooning a newborn star, has been discovered astronomers using ALMA. This unique hot molecular core is the first of its kind to have been detected outside the Milky Way galaxy. It has a very different molecular composition from similar objects in our own galaxy -- a tantalizing hint that the chemistry taking place across the Universe could be much more diverse than expected.
Publ.Date : Thu, 29 Sep 2016 08:20:19 EDT
How to merge two black holes in a simple way
The merger of two black holes, such as the one that produced the gravitational waves discovered by the LIGO Observatory, is considered an extremely complex process that can only be simulated by the world's most powerful supercomputers. However, two theoretical physicists have demonstrated that what occurs on the space-time boundary of the two merging objects can be explained using simple equations, at least when a giant black hole collides with a tiny black hole.
Publ.Date : Mon, 26 Sep 2016 09:59:56 EDT
ALMA Explores the Hubble Ultra Deep Field: Deepest ever millimeter observations of early Universe
International teams of astronomers have used the Atacama Large Millimeter/submillimeter Array (ALMA) to explore the distant corner of the Universe first revealed in the iconic images of the Hubble Ultra Deep Field (HUDF). These new ALMA observations are significantly deeper and sharper than previous surveys at millimetre wavelengths. They clearly show how the rate of star formation in young galaxies is closely related to their total mass in stars. They also trace the previously unknown abundance of star-forming gas at different points in time, providing new insights into the “Golden Age” of galaxy formation approximately 10 billion years ago.
Publ.Date : Thu, 22 Sep 2016 14:16:48 EDT
Cosmology safe as universe has no sense of direction
The universe is expanding uniformly. Space isn't stretching in a preferred direction or spinning.
Publ.Date : Thu, 22 Sep 2016 09:38:23 EDT
In exploring the ‘now,’ new theory links flow of time with Big Bang
A simple question from his wife -- Does physics really allow people to travel back in time? -- propelled a physicist on a quest to resolve a fundamental problem that had puzzled him throughout his 45-year career: Why does the arrow of time flow inexorably toward the future, constantly creating new "nows"?
Publ.Date : Wed, 21 Sep 2016 12:12:34 EDT
Galactic fireworks illuminate monster hydrogen blob in space
An international team of researchers using ALMA and other telescopes has discovered the power source illuminating a so-called Lyman-alpha Blob -- a rare, brightly glowing, and enormous concentration of gas in the distant universe.
Publ.Date : Wed, 21 Sep 2016 08:50:46 EDT
Explaining why the universe can be 'transparent': Universe's reionization is based on a galaxy's dust content
Scientists can explain why the universe has enough energy to become transparent. The study marks the first quantitative study of how the gas content within galaxies scales with the amount of interstellar dust.
Publ.Date : Mon, 12 Sep 2016 17:38:40 EDT
Discovery nearly doubles known quasars from the ancient universe
Quasars are supermassive black holes that sit at the center of enormous galaxies, accreting matter. They shine so brightly that they are often referred to as beacons and are among the most-distant objects we can currently study. A team has discovered 63 new quasars from when the universe was only a billion years old, almost doubling the number of ancient quasars previously known.
Publ.Date : Mon, 12 Sep 2016 08:46:45 EDT
Reconciling dwarf galaxies with dark matter
Dwarf galaxies are enigmas wrapped in riddles. Although they are the smallest galaxies, they represent some of the biggest mysteries about our universe. While many dwarf galaxies surround our own Milky Way, there seem to be far too few of them compared with standard cosmological models, which raises a lot of questions about the nature of dark matter and its role in galaxy formation. New theoretical modeling work offers the most accurate predictions to date about the dwarf galaxies in the Milky Way's neighborhood.
Publ.Date : Wed, 07 Sep 2016 13:51:50 EDT
Hubble discovers rare fossil relic of early Milky Way
A fossilized remnant of the early Milky Way harboring stars of hugely different ages has been revealed by an international team of astronomers. This stellar system resembles a globular cluster, but is like no other cluster known. It contains stars remarkably similar to the most ancient stars in the Milky Way and bridges the gap in understanding between our galaxy's past and its present.
Publ.Date : Wed, 07 Sep 2016 11:23:47 EDT
First gravitational waves form after 10 million years
If two galaxies collide, the merging of their central black holes triggers gravitational waves, which ripple throughout space. An international research team has now calculated that this occurs around 10 million years after the two galaxies merge -- much faster than previously assumed.
Publ.Date : Mon, 05 Sep 2016 06:48:29 EDT