Biggest thing in the universe

Second: Hercules A Hubble image of Hercules A, NASA The elliptical galaxy designated as Hercules A is the second-largest galaxy known to exist. Hercules A has an estimated diameter of 1.5 million light-years, and like IC 1101, it is classified as a supergiant elliptical galaxy. Other than its size and galaxy type, not much is known about Hercules A, and there is a reason for this. The supermassive black hole at the center of Hercules A is currently emitting two gigantic beams of radio waves. These beams are so energetic that they make it difficult to study the rest of the galaxy in detail. Even these beams of radio waves are gigantic, measuring over one million light-years in length. Third: A2261-BCG A2261-BCG is the third-largest known galaxy in the universe, having a diameter of one million light-years, roughly ten times the size of the Milky Way. A2261-BCG is a supergiant elliptical galaxy and is estimated to contain over ten trillion stars. A2261-BCG is a rather strange galaxy for one simple fact: it does not contain a supermassive black hole at its Fourth: ESO 306-17 The fourth-largest known galaxy in the universe is ESO 306-17, with a diameter of roughly one million light-years. Like the galaxies discussed previously, ESO 306-17 is a supergiant elliptical galaxy, yet there is something that makes this particular galaxy unique. While most galaxies find themselves within vast clusters of galaxies, ESO 306-17 is alone, with all of the surrounding space being empty. Astr...

If our Sun were to be replaced by the red hypergiant UY Scuti, a massive 16 AU across, the star’s edge would reach past the orbit of Jupiter Whichever is truly in the lead, it is unlikely to remain there for long. These stars are in the later stages of their lives and have at most a few million years left before they go supernova, leaving behind a glorious nebula. A guide to cosmic measurements: • 1 astronomical unit = 150 million km (distance from the Earth to the Sun) • 1 Solar radius = 695,000km (distance from the edge of the Sun to its centre) • 1 lightyear = 9 trillion km (distance light travels in a year) The largest of galaxies are ellipticals, huge collections of stars that form when two or more smaller galaxies collide and merge together, stripping out all the gas and dust in the process. IC 1101, the largest known galaxy in the Universe. Credit: NASA - SDSS Though galaxies are the largest things you can look at through a telescope and recognise, there are structures that are larger still. Galaxies clump together into clusters, and the most extreme that’s currently known is El Gordo or ‘the fat one’. A view of the cosmic web. Each yellow dot represents a galaxy. Credit: Millenium Simulation Project Pushing the limits For all the titans we have found in our Universe, could there be a bigger monster out there? Limits on physical diameter can be hard to pin down, as mass, temperature, composition and age all play into their size. However, their masses are much more c...

The largest known ‘object’ in the Universe is the Hercules-Corona Borealis Great Wall. This is a ‘galactic filament’, a vast cluster of galaxies bound together by gravity, and it’s estimated to be about 10 billion light-years across! However, this is not really a ‘celestial body’ – a term which normally implies a tightly-bound object like a star or a galaxy. The largest known elliptical galaxy is thought to be IC 1101 (with a diameter of four million light-years), and the largest known spiral galaxy is Malin 1 (with a diameter of 650,000 light-years). Meanwhile, the largest star by radius is thought to be UY Scuti, a red hypergiant star in the constellation of Scutum that has an estimated radius of over a billion kilometres – 1,700 times that of the Sun.

We can define physical reality pragmatically as all that which exists in the cosmos, and there is no such thing as complete emptiness in it. Quite the opposite, it seems that the more we learn about nature, the busier space becomes. We can contemplate the idea of a metaphysical emptiness, a complete void where there is nothing. But these are concepts we make up, not necessarily things that exist. Even calling nothingness a “thing” makes it into something. Leucippus and Democritus, the Greek philosophers credited with the invention of — that everything is made of tiny bits of matter that cannot be divided — suggested the joint existence of atoms and the void. Atoms make up everything that exists, but they move in a complete emptiness, the void. Fields that link the Universe As an exercise in the always evolving way we figure things out about the world, we can make a list of the things we know fill up empty space. (The list does change. For example, 120 years ago, it would have included the If an object sensitive to the field is placed within its range, it will respond in some way, usually by being attracted to or repelled by the source that creates the field. In classical physics we know of only two forces, gravitational and electromagnetic. Every object with mass attracts every other object. You attract and are attracted by everything that exists — by butterflies and whales, by the Sun and all the planets of this Solar System and across the Universe. The intensity of an ob...

There's some pretty big stuff out there in the Universe, but how big is the biggest? According to a team of Hungarian-US scientists led by Prof Lajos Balazs, the largest regular formation in the Universe is a ring of nine galaxies 7 billion light years away and 5 billion light years wide. Though not visible from Earth, the newly discovered feature covers a third of our sky. The ring was revealed by nine Gamma-Ray Bursts (GRB) originating from the nine galaxies. GRBs are the brightest, most energetic events in the cosmos, putting out as much energy in seconds as the Sun will in its entire lifetime. They're caused by supernovae or hypernovae – supermassive stars collapse into neutron stars or black holes in times ranging from milliseconds to a few hours. Aside from their spectacular deaths, they also help astronomers to measure the distance of other galaxies. In this case, the observed GRB's indicate that the nine galaxies are positioned in a ring shaped like a shell. They also show that the galaxies are all of a very similar distance from Earth – according to Prof Balazs, there's only a 1 in 20,000 chance that the ring's arrangement is accidental. If it was visible to us, the ring would cover 36 percent of the sky, making it 70 times bigger than a full moon. The importance of the ring isn't just that it appears to be a record breaker – it raises questions about the architecture of the Universe. In particular, it casts doubts on the Cosmological Principle. First asserted by ...