The "Wing" of the Small Magellanic Cloud
Over the past decade, NASA's Spitzer Space Telescope has captured magnificent images and triggered an impressive list of discoveries, while also helping astronomers study many comets, stars, asteroids, planets.
This image shows young stars in the Small Magellanic Cloud (SMC), one of the closest galaxies to our Milky Way.
Astronomers call all elements heavier than hydrogen and helium "metals." The Wing is a region known to have fewer metals compared to most areas within the Milky Way.
Credit: X-ray: NASA/CXC/Univ.Potsdam/L.Oskinova et al; Optical: NASA/STScI; Infrared: NASA/JPL-Caltech
Newborn stars peek out from beneath their natal blanket of dust in this dynamic image of the Rho Ophiuchi dark cloud.
Called "Rho Oph" by astronomers, it's one of the closest star-forming regions to our own solar system. Located near the constellations Scorpius and Ophiuchus, the nebula is about 407 light years away from Earth.
Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA
This composite image of the Tycho supernova remnant shows the scene more than four centuries after the brilliant star explosion witnessed by Tycho Brahe and other astronomers of that era.
The explosion has left a blazing hot cloud of expanding debris (green and yellow). The location of the blast's outer shock wave can be seen as a blue sphere of ultra-energetic electrons.
A colony of hot, young stars is stirring up the cosmic scene in this new picture from NASA's Spitzer Space Telescope.
The image shows the Orion nebula, a happening place where stars are born. The young stars dip and peak in brightness due to a variety of reasons. Shifting cold and hot spots on the stars' surfaces cause brightness levels to change, in addition to surrounding disks of lumpy planet-forming material, which can obstruct starlight. Spitzer is keeping tabs on the young stars, providing data on their changing ways.
The hottest stars in the region, called the Trapezium cluster, are bright spots at center right. Radiation and winds from those stars has sculpted and blown away surrounding dust. The densest parts of the cloud appear dark at center left.
Credit: NASA/JPL-Caltech/J. Stauffer
The Helix nebula is a cosmic starlet often photographed by amateur astronomers for its vivid colors and eerie resemblance to a giant eye.
The nebula, located about 700 light-years away in the constellation Aquarius, belongs to a class of objects called planetary nebulae. Discovered in the 18th century, these colorful beauties were named for their resemblance to gas-giant planets like Jupiter.
Planetary nebulae are the remains of stars that once looked a lot like our sun. When sun-like stars die, they puff out their outer gaseous layers. These layers are heated by the hot core of the dead star, called a white dwarf, and shine with infrared and visible colors. Our own sun will blossom into a planetary nebula when it dies in about 5 billion years.
Credit: NASA/JPL-Caltech/Univ.of Ariz.
In this Spitzer image, the myriad of stars crowding the center of our galaxy creates the blue haze that brightens towards the center of the image. The green features are from carbon-rich dust molecules, called polycyclic aromatic hydrocarbons, which are illuminated by the surrounding starlight as they swirl around the galaxy's core. The yellow-red patches are the thermal glow from warm dust. The polycyclic aromatic hydrocarbons and dust are associated with bustling hubs of young stars. These materials, mixed with gas, are required for making new stars.
The brightest white feature at the center of the image is the central star cluster in our galaxy. At a distance of 26,000 light years away from Earth, it is so distant that, to Spitzer's view, most of the light from the thousands of individual stars is blurred into a single glowing blotch. Astronomers have determined that these stars are orbiting a massive black hole that lies at the very center of the galaxy.
Zeta Ophiuchi is a young, large and hot star located around 370 light-years away. It dwarfs our own sun in many ways -- it is about six times hotter, eight times wider, 20 times more massive, and about 80,000 times as bright. Even at its great distance, it would be one of the brightest stars in the sky were it not largely obscured by foreground dust clouds.
This massive star is travelling at a snappy pace of about 54,000 mph, fast enough to break the sound barrier in the surrounding interstellar material. Because of this motion, it creates a spectacular bow shock ahead of its direction of travel (to the left). The structure is analogous to the ripples that precede the bow of a ship as it moves through the water, or the sonic boom of an airplane hitting supersonic speeds.
A surprisingly bright superbubble
The star cluster NGC 1929 contains massive stars that produce intense radiation, expel matter at high speeds, and race through their evolution to explode as supernovas. The winds and shock waves carve out huge cavities called superbubbles in the surrounding gas.
Credit: X-ray: NASA/CXC/U.Mich./S.Oey, IR: NASA/JPL, Optical: ESO/WFI/2.2-m
This cloud of glowing gas is the Iris nebula. The main cluster of stars within the nebula is called NGC 7023. It lies 1,300 light-years away in the Cepheus constellation.
Between 2003 and 2005, thanks to its unprecedented sensitivity, NASAs Spitzer Space Telescope created maps of regions like this, showing the location of complex organic molecules called polycyclic aromatic hydrocarbons (PAHs). PAHs may be precursors to the organic ingredients that kick started life on Earth.
Spiral Galaxy Messier 81
Located in the northern constellation of Ursa Major (which also includes the Big Dipper), this galaxy is easily visible through binoculars or a small telescope.
Because of its proximity, M81 provides astronomers with an enticing opportunity to study the anatomy of a spiral galaxy in detail. The unprecedented spatial resolution and sensitivity of Spitzer at infrared wavelengths show a clear separation between the several key constituents of the galaxy: the old stars, the interstellar dust heated by star formation activity, and the embedded sites of massive star formation. The infrared images also permit quantitative measurements of the galaxy's overall dust content, as well as the rate at which new stars are being formed.
Credit: NASA/JPL-Caltech/S. Willner (Harvard-Smithsonian Center for Astrophysics)
Globular cluster Omega Centauri
A cluster brimming with millions of stars glistens like an iridescent opal. Called Omega Centauri, the sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the 150 or so similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus.
Globular clusters are some of the oldest objects in our universe. Their stars are over 12 billion years old, and, in most cases, formed all at once when the universe was just a toddler. Omega Centauri is unusual in that its stars are of different ages and possess varying levels of metals, or elements heavier than boron. Astronomers say this points to a different origin for Omega Centauri than other globular clusters: they think it might be the core of a dwarf galaxy that was ripped apart and absorbed by our Milky Way long ago.
Credit: NASA/JPL-Caltech/M.Boyer (University of Minnesota)
Coiled creature of the night
NASA's Spitzer Space Telescope has imaged a wild creature of the dark -- a coiled galaxy with an eye-like object at its center.
The galaxy, called NGC 1097, is located 50 million light-years away. It is spiral-shaped like our Milky Way, with long, spindly arms of stars. The "eye" at the center of the galaxy is actually a monstrous black hole surrounded by a ring of stars. In this color-coded infrared view from Spitzer, the area around the invisible black hole is blue and the ring of stars, white.
Credit: NASA/JPL-Caltech/The SINGS Team (SSC/Caltech)
Eye in the sky
These shape-shifting galaxies have taken on the form of a giant mask. The icy blue eyes are actually the cores of two merging galaxies, called NGC 2207 and IC 2163, and the mask is their spiral arms.
The two galaxies are tugging at each other, stimulating new stars to form. Eventually, this cosmic ball will come to an end, when the galaxies meld into one. The dancing duo is located 140 million light-years away in the Canis Major constellation.
Credit: NASA, ESA/JPL-Caltech/STScI/D. Elmegreen (Vassar)
The Sombrero Galaxy
Named after its appearance in visible light to a wide-brimmed hat -- this galaxy is in fact two galaxies in one. It is a large elliptical galaxy (blue-green) with a thin disk galaxy (partly seen in red) embedded within. Previous visible-light images led astronomers to believe the Sombrero was simply a regular flat disk galaxy.
The Sculptor Galaxy
Also known as NGC 253, the Sculptor galaxy is part of a cluster of galaxies visible to observers in the Southern hemisphere. It is known as a starburst galaxy for the extraordinarily strong star formation in its nucleus. This activity warms the surrounding dust clouds, causing the brilliant yellow-red glow in the center of this infrared image.
On the top right is a blue glow primarily from the light of stars as seen at the shorter wavelengths of infrared light. In this view, the disk, spiral arms and central bar are much easier to identify than in visible light because the obscuring effects of dust are minimized.
The lower right image shows the glow of dust at longer infrared wavelengths in green and red. Regions of star formation glow especially bright at the longest wavelengths (red).
The tortured clouds of Eta Carinae
Massive stars can wreak havoc on their surroundings, as can be seen in this view of the Carina nebula. The bright star at the center of the nebula is Eta Carinae, one of the most massive stars in the galaxy. Its blinding glare is sculpting and destroying the surrounding nebula.
Eta Carinae is a true giant of a star. It is around 100 times the mass of our sun and is burning its nuclear fuel so quickly that it is at least one million times brighter than the sun. It has brightened and faded over the years, and some astronomers think it could explode as a supernova in the not-too-distant future.
Such a tremendous outflow of energy comes at a great cost to the surrounding nebula. The infrared light from the star destroys particles of dust, sculpting cavities and leaving pillars of denser material that point back to the star. Spitzers infrared vision lets us see the dust, shown in red, as well as clouds of hot, glowing gas that appear green.