Category Archives: Deep Space Objects
Astronomers still have yet to directly capture an image of a black hole—they’re working on it—but they know where some of the largest ones are: inside the hearts of galaxies, where they power brilliant and powerful quasars whose light can be seen across the Universe. Some of these supermassive black holes (SMBs) can contain the mass of millions if not billions of Sun-sized stars and, when two galaxies happen to collide (which they often do) their respective resident SMBs can end up locked in an orbital embrace. As their spinning dance grows tighter and tighter they send out gravitational waves, rippling the very fabric of space and time itself (the LIGO experiment announced the first detection of these waves in 2016.) But if the gravitational waves are uneven, say because the two merging SMBs are of vastly different masses and/or individually spinning in different orientations (a possible but not common scenario) then the super-duper-supermassive black hole that results from the merger can end up getting one serious cosmic-scale kick after the event occurs and the waves shut off—perhaps a strong enough kick to send it hurtling out of the galaxy altogether.
That’s what astronomers think we’re witnessing here in this image from the Hubble Space Telescope.
Supernovas are some of the most powerful and energetic events in the entire Universe. When a dying star explodes you wouldn’t want to be anywhere nearby—fresh elements are nice and all, but the energy and radiation from a supernova would roast any planets within tens if not hundreds of light-years in all directions. Luckily for us we’re not in an unsafe range of any supernovas in the foreseeable future, but there was a time not very long ago (in geological terms) that these stellar explosions occurred nearby (in astronomical terms) and in 2016 scientists found the “smoking gun” evidence at the bottom of the ocean.
What’s more, the arrival of the iron-rich fallout from those stellar explosions seems to coincide with ancient global temperature changes*, the most recent dated near the start of the last major ice age which brought lower sea levels, widespread glaciation…and eventually the rise of the first modern humans.
Read more at Universe Today here: Nearby Supernovas Showered Earth With Iron
*Note: the changes in climate referred to here are not the same as the climate change we are witnessing today. Not only are we now seeing rapid warming of land and sea temperatures globally, but today’s forcings are the result of increasing greenhouse gases like carbon dioxide in the atmosphere—not radioactive iron from exploding stars.
The European Southern Observatory’s unimaginatively-named but incredibly powerful Very Large Telescope (VLT) located on a remote plateau high in the mountains of Chile’s Atacama Desert has captured a detailed view of NGC 1055, a spiral galaxy a little larger than our own located 55 million light-years away. On galactic scales this is relatively close by, and our edge-on perspective allows astronomers to determine the three-dimensional structure of this island of stars.
Spiral galaxies across the Universe can be found at all angles in relation to our viewpoint here on Earth. Some we see “face on,” which dramatically shows a spiral galaxy’s long, arcing arms and bright center but make it difficult to get a sense of true shape or variations in density. With NGC 1055 we see it “on edge,” without which it likely wouldn’t be known that it’s being tugged by one of its galactic neighbors.
Read the full story from ESO here: A Galaxy on the Edge
In what’s being called a “record-breaking exoplanet discovery” NASA announced today the detection of not one, not two, not three or four but seven exoplanets orbiting the ultra-cool dwarf star TRAPPIST-1, located just under 40 light-years away in the constellation Aquarius. (That’s astronomically very close, although still 235 trillion miles distant.) What’s more, these exoplanets aren’t bloated hot Jupiters or frigid Neptune-like worlds but rather dense, rocky planets similar in size to Earth…and at least three of them are well-positioned around their dim red star to permit liquid water to exist on their surfaces.
TRAPPIST-1 and its planets are like a miniature version of our inner Solar System; the star itself is only slightly larger than Jupiter with a mass about 8% of our Sun, and the planets B through H all have orbits smaller than the diameter of Mercury’s. Still, even an ultra-cool dwarf star has a habitable zone, and three of these planets lie within it. The others may very well also possess habitable regions on or inside them too.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington, D.C. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
The seven-planet system was confirmed through (and named for) the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope as well as observations from NASA’s Spitzer Space Telescope.
“This is the most exciting result I have seen in the 14 years of Spitzer operations,” said Sean Carey, manager of NASA’s Spitzer Science Center at Caltech/IPAC in Pasadena. “Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets.”
A star’s violent death by black hole has been spotted by researchers from the University of New Hampshire, using observations made by three orbiting x-ray space telescopes. Located in a small galaxy 1.8 billion light-years away, the event demonstrates what happens when a star gets too close to a supermassive black hole and gets torn apart, some of its material falling into the black hole but also some getting thrown outwards at high speeds—all heated to temperatures intensely high enough to shine in x-ray wavelengths.
“We have witnessed a star’s spectacular and prolonged demise,” said Dacheng Lin, a research scientist at UNH’s Space Science Center and the study’s lead author. “Dozens of these so-called tidal disruption events [TDEs] have been detected since the 1990s, but none that remained bright for nearly as long as this one.”
The extraordinary long bright phase of this TDE means that either this was the most massive star ever to be torn apart during one of these events, or the first where a smaller star was completely torn apart.
Read the rest of this story from the University of New Hampshire here: UNH Researcher Discovers a Black Hole Feeding Frenzy that Breaks Records