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.
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
We’re all used to seeing fantastic images of Saturn and its family of moons from NASA’s Cassini spacecraft, which has spent the last decade in orbit around the ringed world. But every now and then Cassini aims its cameras outwards, capturing images of the sky beyond Saturn – just like we might look up at the stars from here on Earth. And while it’s not designed to be a deep-space observatory like Hubble or Subaru (or even like a modest backyard telescope, really) Cassini can still resolve many of the same stars we can easily see in the night sky… and, on April 12, 2015, it spotted something much farther away: the Sombrero Galaxy (M104), 29 million light-years distant!
Coincidentally Cassini grabbed its image of M104 exactly five years after it was imaged with Japan’s Subaru Telescope, located atop Mauna Kea.
It’s Hubble’s 25th anniversary in space this year but it seems like we’re the ones getting all the presents! Yesterday NASA released two new high-def versions of the famous “Pillars of Creation” image, and now today there’s this: Hubble’s most detailed image ever of the Andromeda Galaxy!
Containing over 100 million stars it’s not just the best view yet of Andromeda – it’s also the most expansive image ever made with Hubble. Although the galaxy is 2.5 million light-years away it extends across an area larger than the full Moon in the sky, so to create such a detailed mosaic Hubble had to obtain 7,398 images taken over 411 individual pointings! It’s 1.5 billion pixels covering an area over 40,000 light-years across.
According to NASA, it’s “like photographing a beach and resolving individual grains of sand.” Wow!
Check out the full image below:
Think the Milky Way is a big place? Think again — check out this graphic by Arecibo astrophysicist Rhys Taylor, which neatly illustrates the relative sizes of 25 randomly-selected galaxies using images made from NASA and ESA observation missions. It even includes a rendering of our own remarkably mundane galaxy at the center for comparison.
(Warning: this chart may adversely affect any feelings of galactic superiority you may have once held dear.)