Category: Astronomy

NGC 6543 or the Cat’s Eye Nebula, discovered by William Herschel on February 15, 1786, is a relatively bright 8.1 magnitude planetary nebula in the constellation of Draco, situated almost exactly in the direction of the North Ecliptic Pole. The Nebula lies 3,000 light-years from Earth. Structurally, it is one

V838 Mon is one of the prettiest exploded star remnant formations. It is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy. In early 2002, astronomers witnessed an enormous explosion emanating from V838

The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years (2.4×1019 km) from Earth in the Andromeda constellation, which was named after the mythological princess Andromeda. Also known as Messier 31 or NGC 224, it is often referred to as the Great Andromeda Nebula in older texts. The Andromeda Galaxy

It is a dark nebula in the constellation Orion, located just south of the star Alnitak, and is part of the much larger Orion Molecular Cloud Complex, approximately 1500 light years from Earth. It is one of the most identifiable nebulae because of the shape of its swirling cloud of

This beautiful image offers a peek inside a cavern of roiling dust and gas where thousands of stars are forming. The image, taken by the Advanced Camera for Surveys (ACS) aboard NASA’s Hubble Space Telescope, represents the sharpest view ever taken of this region, called the Orion Nebula. More than

This is one of my favourite galaxies, in fact, it is a collision of two galaxies, the NGC 4038 and 4039. Its shape gives the name away. It’s in the Corvus constellation in the Southern Hemisphere, encompassed by the Virgo and Hydra constellations. It is a favourite because it shows

Astronomers have discovered a distant planet that appears to have an atmosphere similar to Earth, the possibility of water at its surface and the theoretical potential to support life. It is the first validated planet found in the “habitable zone,” defined by the distance from a star that might allow

Are all nebulae and galaxy photos false colour? Even NASA ones? Most of the nebulae and galaxy photos are what we would call false colour – although it’s probably much more fair to the people who make these images to call them “exaggerated colour”, or perhaps “reconstructed colour”. These images

Using European Southern Observatory’s Very Large Telescope Interferometer (VLTI), Olivier Chesneau (Observatoire de la Côte d’Azur, Nice, France) and an international team of collaborators have found that the yellow hypergiant star HR 5171 A is 1300 times the diameter of the Sun and much bigger than was expected. It is

The Milky Way’s Local Arm is Metropolitan Earth’s arm of the galaxy is muscular, astronomers announced June 3 at the 222nd American Astronomical Society meeting in Indianapolis. While the Local Arm first appeared to be a mere “spur” of the larger Sagittarius or Perseus arms between which it is sandwiched,

The Milky Way Wobbles Our galaxy rotates around the supermassive black hole at its centre. But, as scientists describe online in the October 2013 issue of the Monthly Notices of the Royal Astronomical Society, it do not simply orbit the galactic centre in straightforward ellipses but bob up and down

Black Holes’ Jets Black holes represent the extremes of gravity and density. These compact objects come in a wide range of masses: Stellar-mass black holes weigh in at a few to tens of times that of the Sun, while supermassive black holes at the centres of galaxies hold millions to

How disorderly is the universe? Entropy – disorder – increases with time, according to the second law of thermodynamics. When it maxes out, the temperature will be the same everywhere across the universe. This will happen when stars and galactic cores stop producing energy and are so far apart that

In 1997, a host of ground-based and space telescopes confirmed that gamma-ray bursts – fleeting blasts of high energy radiation – are nature’s biggest explosions. The Italian-Dutch satellite BeppoSAX pin-pointed the February 28 burst, and Earth-based optical instruments were then able to spot its faint host galaxy several billion light-years

The Cosmic Web Starting in the 1980s, astronomers came to realize that the contents of the universe are not spread smoothly throughout space. Clusters of galaxies bunch together along filaments separated by huge voids where few galaxies exist. The overall structure, dubbed the ‘cosmic web,’ likely arose in the early

With a recently acquired beginner telescope, the Lyra Constellation’s various stars came into full view with a clarity previously denied through a pair of binoculars. Lyra is a constellation in the northern hemisphere. It was introduced by the Greek astronomer Ptolemy in the 2nd century. The constellation is associated with

Dark Matter in the Universe In 1933, Swiss astronomer Fritz Zwicky discovered that the visible matter contained in the galaxies of the vast Coma cluster is barely 10% of the amount needed to keep the galaxies bound together. This is the first indication that the universe has vast quantities of

Measurement of Stars’ Luminosities In the 1910s, Danish astronomer Ejnar Hertzsprung and American Henry Norris Russell independently plotted the luminosities or intrinsic brightnesses of stars against their temperatures or colours. They found that most stars lie along a narrow strip that runs from hot and luminous to cool and dim

Inflation in the Universe The Universe has been expanding since the Big Bang, but there may have been a time called the inflationary era, when the Universe grew10⁷⁸ times its size in 10³⁶ seconds. If the inflationary epoch happened, it would make the current Universe much bigger than it would

Telescopes can see galaxies whose light has been travelling almost 13.8 billion years and thus look as they did just after the Big Bang. Because the Universe is expanding at an accelerated rate, those galaxies are now some 46 billion light-years away. The observable Universe thus has a diameter of