The Hubble Space Telescope offers this delightful view of the crowded stellar encampment called Messier 68, a spherical, star-filled region of space known as a globular cluster. Mutual gravitational attraction amongst a cluster’s hundreds of thousands or even millions of stars keeps stellar members in check, allowing globular clusters to hang together for many billions of years.
Astronomers can measure the ages of globular clusters by looking at the light of their constituent stars. The chemical elements leave signatures in this light, and the starlight reveals that globular clusters’ stars typically contain fewer heavy elements, such as carbon, oxygen and iron, than stars like the Sun.
Since successive generations of stars gradually create these elements through nuclear fusion, stars having fewer of them are relics of earlier epochs in the Universe. Indeed, the stars in globular clusters rank among the oldest on record, dating back more than 10 billion years.
More than 150 of these objects surround our Milky Way galaxy. On a galactic scale, globular clusters are indeed not all that big. In Messier 68’s case, its constituent stars span a volume of space with a diameter of little more than a hundred light-years. The disc of the Milky Way, on the other hand, extends over some 100 000 light-years or more.
Messier 68 is located about 33 000 light-years from Earth in the constellation Hydra.
The 2012 transit of Venus and the Hubble Space Telescope
Astrophotographer Thierry Legault captured this transit of the HST (Hubble Space Telescope) from Queensland, Australia, simultaneously with the 2012 transit of Venus on June 6th, at 01:42:25 UTC. Thanks to the continuous shooting mode of the Nikon D4 DSLR running at 10 fps, 9 images of the HST were recorded during its 0.97 seconds transit. Due to the differences in distance from Earth of Hubble vs. Venus, Venus took a lazy 6-plus hours to make its transit. A few giant sunspots also join in the view.
To celebrate the 22nd anniversary of the NASA/ESA Hubble Space Telescope this month, episode 54 of the Hubblecast gives a slideshow of some of the best images from over two decades in orbit, set to specially commissioned music.
Several million stars are vying for attention in this Hubble Space Telescope image of a raucous stellar breeding ground in 30 Doradus, located in the heart of the Tarantula nebula. The image is being released to celebrate Hubble’s 22nd anniversary.
30 Doradus is the brightest star-forming region in our galactic neighbourhood and home to the most massive stars ever seen. The nebula resides 170,000 light-years away in the Large Magellanic Cloud, a small, satellite galaxy of our Milky Way. No known star-forming region in our galaxy is as large or as prolific as 30 Doradus.
The image is roughly 650 light-years across and comprises one of the largest mosaics ever assembled from Hubble photos and consists of observations taken by Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys, combined with observations from ESO’s MPG/ESO 2.2-metre telescope that trace the location of glowing hydrogen and oxygen.
The region’s sparkling centerpiece is a giant, young star cluster named NGC 2070, only 2-3 million years old. Its stellar inhabitants number roughly 500,000. The cluster is a hotbed for young, massive stars. Its dense core, known as RMC 136, is packed with some of the heftiest stars found in the nearby Universe, weighing more than 100 times the mass of our Sun.
The image reveals a fantasy landscape of pillars, ridges, and valleys. The massive stars are carving deep cavities in the surrounding material by unleashing a torrent of ultraviolet light, which is etching away the enveloping hydrogen gas cloud in which they were born. When this radiation hits dense walls of gas, it creates shocks, which may be generating a new wave of star birth.
Images:1. Hubble’s panoramic view of the 30 Doradus (also known as the Tarantula Nebula) star-forming region. 2. Labelled view of the Tarantula Nebula identifying several prominent features.
NASA’s Hubble Space Telescope has made over one million observations during its more than two decades in orbit. New images are published nearly every week, but hidden in Hubble’s huge data archives are some truly breathtaking images that have never been seen. They’re called Hubble’s Hidden Treasures, and you can now help to bring them to light.
Between now and May 31, 2012, the European Space Agency (ESA) invites you to explore Hubble’s vast science archive to dig out the best unseen Hubble images. Find a great dataset in the Hubble Legacy Archive (HLA), adjust the contrast and colors, and submit to the Hubble’s Hidden Treasures Contest Flickr group. You’ll be in with a chance to win an iPad among other great prizes.
The Hubble Space Telescope has spotted a UFO — well, the UFO Galaxy, to be precise. NGC 2683 is a spiral galaxy seen almost edge-on, giving it the shape of a classic science fiction spaceship. This is why the astronomers at the Astronaut Memorial Planetarium and Observatory gave it this attention-grabbing nickname.
This side-on view gives astronomers a great opportunity to see the delicate dusty lanes of the spiral arms silhouetted against the golden haze of the galaxy’s core. In addition, brilliant clusters of young blue stars shine scattered throughout the disc, mapping the galaxy’s star-forming regions.
Perhaps surprisingly, side-on views of galaxies like this one do not prevent astronomers from deducing their structures. Studies of the properties of the light coming from NGC 2683 suggest that this is a barred spiral galaxy, even though the angle we see it at does not let us see this directly. NGC 2683 lies in the Northern constellation of Lynx.
Big, beautiful, barred spiral galaxy NGC 1300 lies some 70 million light-years away on the banks of the constellation Eridanus. This Hubble Space Telescope composite view of the gorgeous island universe is one of the largest Hubble images ever made of a complete galaxy.
NGC 1300 spans over 100,000 light-years and the Hubble image reveals striking details of the galaxy’s dominant central bar and majestic spiral arms. In fact, on close inspection the nucleus of this classic barred spiral itself shows a remarkable region of spiral structure about 3,000 light-years across.
Unlike other spiral galaxies, including our own Milky Way, NGC 1300 is not presently known to have a massive central black hole.
The Hubble Space Telescope has produced the most detailed image so far of the globular cluster Messier 9, resolving over 250,000 individual stars right into its crowded centre. Messier 9 is located close to the centre of the galaxy, about 25,000 light-years from Earth. It’s so close that the gravitational forces from the galactic centre pull it slightly out of shape.
Globular clusters are thought to harbour some of the oldest stars in our galaxy, born when the Universe was just a small fraction of its current age. As well as being far older than the Sun — around twice its age — the stars of Messier 9 also have a markedly different composition, and are enriched with far fewer heavier elements than the Sun.
In particular, the elements crucial to life on Earth, like oxygen and carbon, and the iron that makes up our planet’s core, are very scarce in Messier 9 and clusters like it. This is because the Universe’s heavier elements were gradually formed in the cores of stars, and in supernova explosions. When the stars of Messier 9 formed, there were far smaller quantities of these elements in existence.
Hubble-Spitzer Color Mosaic of the Galactic Center
This composite color infrared image of the center of our Milky Way galaxy reveals a new population of massive stars and new details in complex structures in the hot ionized gas swirling around the central 300 light-years.
This sweeping panorama is the sharpest infrared picture ever made of the Galactic core, revealing details in objects as small as 20 times the size of our own solar system. The picture measures 300×115 light-years and required 144 Hubble orbits to make 2,304 science exposures. It was taken between Feb. 22 and Jun. 5, 2008.
The image shows a large number of massive stars distributed throughout the region not confined to one of the three known stars clusters in the Galactic Center, known as the Central cluster, the Arches cluster, and the Quintuplet cluster, which are easily seen as tight concentrations of bright, massive stars in the image.
The winds and radiation from these stars form the complex structures seen in the core, and in some cases, they may be triggering new generations of stars. At upper left, large arcs of ionized gas are resolved into arrays of intriguingly organized linear filaments indicating perhaps a critical role of the influence of locally strong magnetic fields.
The lower left region shows pillars of gas sculpted by winds from hot massive stars in the Quintuplet cluster. At the center of the image, ionized gas surrounding the supermassive black hole at the center of the galaxy is confined to a bright spiral embedded within a circum-nuclear dusty inner-tube-shaped torus.
Observations by the Hubble Space Telescope have come up with a new class of planet, a waterworld enshrouded by a thick, steamy atmosphere.
GJ 1214b is a super-Earth about 2.7 times Earth’s diameter and weighs almost seven times as much; most of its mass is made up of water. It orbits a red-dwarf star every 38 hours at a distance of 2 million kilometres, giving it an estimated temperature of 230 degrees Celsius. It is located in the constellation of Ophiuchus, and just 40 light-years from Earth.
Scientists used Hubble to study GJ 1214b when it crossed in front of its host star as its light is filtered through the planet’s atmosphere, giving clues to the mix of gases. They found the spectrum of be featureless over a wide range of wavelengths, or colours. The atmospheric model most consistent with the Hubble data is a dense atmosphere of water vapour.
Since the planet’s mass and size are known, astronomers can calculate the density, of only about 2 grams per cubic centimetre. Water has a density of 1 gram per cubic centimetre, while Earth’s average density is 5.5 grams per cubic centimetre. This suggests that GJ 1214b has much more water than Earth does, and much less rock.
As a result, the internal structure of GJ 1214b would be extraordinarily different from that of our world. The high temperatures and high pressures would form exotic materials like ‘hot ice’ or ‘superfluid water’, substances that are completely alien to our everyday experience.
NASA’s Hubble Telescope captured this image of Eta Carinae, consisting of ultraviolet and visible light images from the High Resolution Channel of Hubble’s Advanced Camera for Surveys.
The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star.
The huge clouds of matter thrown out a century and a half ago, known as the Homunculus Nebula, have been a regular target for Hubble since its launch in 1990. This image is the most detailed yet, and shows how the material from the star was not thrown out in a uniform manner, but forms a huge dumbbell shape.
Eta Carinae is one of the closest stars to Earth that is likely to explode in a supernova in the relatively near future. When it does, expect an impressive view from Earth, far brighter still than its last outburst: SN 2006gy, the brightest supernova ever observed, came from a star of the same type, though from a galaxy over 200 million light-years away.
The Eagle Has Risen: Stellar Spire in the Eagle Nebula
Appearing like a winged fairy-tale creature poised on a pedestal, this object is actually a billowing tower of cold gas and dust rising from a stellar nursery called the Eagle Nebula. The soaring tower is 9.5 light-years or about 57 trillion miles high (91.7 trillion km), about twice the distance from our Sun to the next nearest star.
Stars in the Eagle Nebula are born in clouds of cold hydrogen gas that reside in chaotic neighborhoods, where energy from young stars sculpts fantasy-like landscapes in the gas. The tower may be a giant incubator for those newborn stars. A torrent of ultraviolet light from a band of massive, hot, young stars [off the top of the image] is eroding the pillar.
The starlight also is responsible for illuminating the tower’s rough surface. Ghostly streamers of gas can be seen boiling off this surface, creating the haze around the structure and highlighting its three-dimensional shape. The column is silhouetted against the background glow of more distant gas.
The dominant colors in the image were produced by gas energized by the star cluster’s powerful ultraviolet light. The blue color at the top is from glowing oxygen. The red color in the lower region is from glowing hydrogen.
Sometimes astronomers see things on the sky they don’t immediately understand. In 1985 this happened to Arturo Gomez, and the object became known as Gomez’s Hamburger for its distinctive yet familiar shape.
After some investigation, the object was identified as a proto-planetary nebula, a gas cloud emitted by a Sun-like star just after its central hydrogen fuel has all been fused to helium.
Gomez’s Hamburger is on its way to becoming a full-fledged planetary nebula in a few thousand years. The light seen (the bun) is reflected by dust from the central star, although the star itself is obscured by a thick dust disk that runs across the middle (the patty).
Gomez’s Hamburger, pictured above by the Hubble Space Telescope, is only a fraction of a light year across but located approximately 10,000 light years away towards the constellation of Sagittarius.
The Hubble Space Telescope has taken a picture of the barred spiral galaxy NGC 1073, which is found in the constellation of Cetus. This image offers a particularly clear view of the galaxy’s central bar, which are thought to emerge as gravitational density waves funnel gas toward the centre, supplying the material to create new stars and feeding the supermassive black hole.
In the upper left part of the image, a rough ring-like structure of recent star formation hides a bright source of X-rays. Called IXO 5, this X-ray source is likely to be a binary system featuring a black hole and a star orbiting each other.
Right across Hubble’s field of view, more distant galaxies are peering through NGC 1073, with several reddish examples appearing clearly in the top left part of the frame. Three of the bright points of light are quasars, incredibly bright sources of light caused by matter heating up and falling into supermassive black holes in galaxies literally billions of light-years from us. [Watch the video]
Messier 100 is a perfect example of a grand design spiral galaxy, a type of galaxy with prominent and very well-defined spiral arms. These dusty structures swirl around the galaxy’s nucleus, and are marked by a flurry of star formation activity that dots Messier 100 with bright blue, high-mass stars.
This image from the Hubble Space Telescope, the most detailed made to date, shows the bright core of the galaxy and the innermost parts of its spiral arms. Messier 100 has an active galactic nucleus — a bright region at the galaxy’s core caused by a supermassive black hole that is actively swallowing material, which radiates brightly as it falls inwards.
The galaxy’s spiral arms also host smaller black holes, including the youngest ever observed in our cosmic neighbourhood, the result of a supernova observed in 1979. Messier 100 is located in the direction of the constellation of Coma Berenices, about 50 million light-years distant.