Weighing in on the Dumbbell Nebula
The Dumbbell nebula (Messier 27) pumps out infrared light in this image from the Spitzer Space Telescope.
Planetary nebulae are known to be 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 a white dwarf, and shine with infrared and visible-light colors. Our own sun will blossom into a planetary nebula when it dies in about five billion years.
The Dumbbell nebula is 1,360 light-years away in the Vulpecula constellation, and stretches across 4.5 light-years of space. That would more that fill the space between our sun and the nearest star, and it demonstrates how effective planetary nebulae are at returning much of a stars material back to interstellar space at the end of their lives.
The diffuse green glow, which is brightest near the center, is probably showing us hot gas atoms being heated by the ultraviolet light from the central white dwarf. A collection of clumps fill the central part of the nebula, and red-colored radial spokes extend well beyond, which are molecules of hydrogen gas mixed with heavier elements. Much of this material may survive intact and mix back into interstellar gas clouds, helping to fuel the next generation of stars.
The Frosty Leo Nebula
Three thousand light-years from Earth lies the strange protoplanetary nebula IRAS 09371+1212, nicknamed the Frosty Leo Nebula. The Frosty Leo Nebula has acquired its curious name as it has been found to be rich in water in the form of ice grains, and because it lies in the constellation of Leo.
This nebula is particularly noteworthy because it has formed far from the galactic plane, away from interstellar clouds that may block our view. The intricate shape comprises a spherical halo, a disc around the central star, lobes and gigantic loops. This complex structure strongly suggests that the formation processes are complex and it has been suggested that there could be a second star, currently unseen, contributing to the shaping of the nebula.
Protoplanetary nebulae like the Frosty Leo Nebula have brief lifespans by astronomical standards and are precursors to the planetary nebula phase, in which radiation from the star will make the nebula’s gas light up brightly. Their rarity makes studying them a priority for astronomers who seek to understand better the evolution of stars.
Sharpless 2-239 is a sprawling stellar nursery about 500 light years away in the Taurus constellation. This image from the Mt. Lemmon SkyCenter in Arizona shows a portion of a much larger complex of over a dozen stars forming inside it. Since these are low mass stars like the Sun, and will merrily fuse hydrogen into helium for billions of years, this is like seeing a human baby when it’s less than a month old.
These stars eject material from both ends: called bipolar outflow, twin jets of material beamed at several hundred kilometers per second in opposite directions. These jets slam into the dense surrounding material, compressing it, heating it up, and causing it to glow. The structure you see fanning out to the lower left is from one of these jets, the one headed more or less toward us.
The red blob just to the left and above the center is the binary star causing all this commotion. It’s called IRS5, and it’s two young stars orbiting each other about 10 billion kilometers apart, emitting the jets. The pink color is from glowing hydrogen gas, and the other colors are from oxygen, nitrogen, and sulfur. The material farther out is so dark and thick it absorbs visible light from the stars inside.
Maelstrom of Star Birth
This is a stunning picture of the most famous stellar factory. In the Orion Nebula hundreds of stars are being born, or are in the early stages of their infancy. Most fascinating is the discovery of small planetary systems being formed around some of the stars in this nebula.
This spectacular colour panorama of the center the Orion nebula is one of the largest pictures ever assembled from individual images taken with the Hubble Space Telescope. The picture, seamlessly composited from a mosaic of 15 separate fields, covers an area of sky about five percent the area covered by the full Moon.
A perfect storm of turbulent gases
This Hubble image shows a bubbly ocean of glowing hydrogen, oxygen, and sulphur gas in a small region within the extremely massive and luminous molecular nebula Messier 17 (M17) — also known as the Omega or Swan Nebula — located about 5500 light-years away in the Sagittarius constellation.
The wave-like patterns of gas have been sculpted and illuminated by a torrent of ultraviolet radiation from young, massive stars (which lie outside the picture to the upper left). The glow of these patterns highlights the 3D structure of the gases. The ultraviolet radiation is carving and heating the surfaces of cold hydrogen gas clouds.
The warmed surfaces glow orange and red in this image. The intense heat and pressure cause some material to stream away from the surface, creating the glowing veil of even hotter green-coloured gas that masks background structures. The pressure on the tips of the waves may trigger new star formation within them.
The image, roughly 3 light-years across, was taken on 29-30 May 1999, with Hubble’s Wide Field Planetary Camera 2. The colours in the image represent various gases. Red represents sulphur; green, hydrogen; and blue, oxygen.
New view of the Great Nebula in Carina
Eta Carinae is one of the most massive and brightest stars in the Milky Way. Compared to our own Sun, it is about 100 times as massive and a million times as bright. This famed variable hypergiant star (upper center) is surrounded by the Carina Nebula.
In this composite image spanning the visible and infrared parts of the spectrum, areas that appear blue are not obscured by dust, while areas that appear red are hidden behind dark clouds of dust in visible light.
A study combining X-ray and Infrared observations has revealed a new population of massive stars lurking in regions of the nebula that are highly obscured by dust. Adding these new massive stars to the known massive stars suggests that the Carina Nebula will produce twice as many supernova explosions as previously supposed.
Airborne observatory views star-forming region W40
A new image from NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) provides the highest resolution mid-infrared image taken to date of the massive star formation region in our galaxy known as W40.
The W40 image was taken by the FORCAST instrument and is a composite of data captured at infrared wavelengths of 5.4, 24.2, and 34.8 microns, all of which are partially or completely blocked by water vapor in Earth’s atmosphere and inaccessible to observatories even on high mountain tops.
W40 is difficult to view with optical telescopes because it lies on the far side of a dense cloud of gas and dust. Infrared observations of the region peer through the dust to reveal a bright nebula, dozens of young stars, and at least six massive stars some six to 20 times the mass of the Sun forming at the center.
At least 50% of the stars in the Milky Way Galaxy formed in massive clusters of thousands of stars similar to W40. Evidence suggests that the solar system developed in such a cluster almost five billion years ago. Because stars are relatively dim at the wavelengths measured by FORCAST, the observed emission in the images is due to dust surrounding the stars that are heated to a few hundred degrees.
Above: This mid-infrared image of the W40 star-forming region of the Milky Way galaxy was captured recently by the FORCAST instrument on the 100-inch telescope aboard the SOFIA flying observatory.
The Cool Clouds of Carina
Observations made with the APEX telescope in submillimetre-wavelength light at a wavelength of 870 µm reveal the cold dusty clouds from which stars form in the Carina Nebula. This site of violent star formation, which plays host to some of the highest-mass stars in our galaxy, is an ideal arena in which to study the interactions between these young stars and their parent molecular clouds.
At this wavelength, most of the light seen is the weak heat glow from cosmic dust grains. The image therefore reveals the clouds of dust and molecular gas — mostly hydrogen — from which stars may form. At -250°C, the dust grains are very cold, and the faint glow emanating from them can only be seen at submillimetre wavelengths, significantly longer than those of visible light.
The APEX LABOCA observations are shown here in orange tones, combined with a visible light image from the Curtis Schmidt telescope. The result is a dramatic, wide-field picture that provides a spectacular view of Carina’s star formation sites. The nebula contains stars with a total mass equivalent to over 25,000 Suns, while the mass of the gas and dust clouds is that of about 140,000 Suns.
Cone Nebula: a ghostly star-forming pillar
This monstrous pillar, also called NGC 2264, resides in a turbulent star-forming region. This picture shows the upper 2.5 light-years of the Cone. The entire pillar is seven light-years long. Radiation from hot, young stars (located beyond the top of the image) has slowly eroded the nebula over millions of years.
Ultraviolet light heats the edges of the dark cloud, releasing gas into the relatively empty region of surrounding space. There, additional ultraviolet radiation causes the hydrogen gas to glow, which produces the red halo of light seen around the pillar.
A similar process occurs on a much smaller scale to gas surrounding a single star, forming the bow-shaped arc seen near the upper left side of the Cone. This arc is 65 times larger than the diameter of our Solar System. The blue-white light from surrounding stars is reflected by dust.
Over time, only the densest regions of the Cone will be left. But inside these regions, stars and planets may form. The Cone Nebula resides 2500 light-years away in the constellation Monoceros.
30 Doradus - The Growing Tarantula Within
The star-forming region, 30 Doradus, is one of the largest located close to the Milky Way and is found in the neighboring galaxy, Large Magellanic Cloud. About 2,400 massive stars in the center of 30 Doradus, also known as the Tarantula Nebula, are producing intense radiation and powerful winds as they blow off material.
Multimillion-degree gas detected in X-rays (blue) by the Chandra X-ray Observatory comes from shock fronts — similar to sonic booms —formed by these stellar winds and by supernova explosions. This hot gas carves out gigantic bubbles in the surrounding cooler gas and dust shown here in infrared emission from the Spitzer Space Telescope (orange).
Eagle Nebula flaunts its infrared feathers
This set of images from NASA’s Spitzer Space Telescope shows the Eagle nebula in different hues of infrared light. Each view tells a different tale. The first picture highlights the contrast between the hot, supernova-heated dust (green) and the cooler dust making up the region’s dusty star-forming clouds and towers (red, blue and purple).
The second view is packed with drama, because it tells astronomers that a star in this region violently erupted, or went supernova, heating surrounding dust (orange). This view also reveals that the hot dust is shell shaped, another indication that a star exploded.
The third picture shows lots of stars and dusty structures with clarity. Dusty molecules found on Earth called polycyclic aromatic hydrocarbons produce most of the red; gas is green and stars are blue.
Star Forming Region S106
Massive star IRS 4 is beginning to spread its wings. Born only about 100,000 years ago, material streaming out from this newborn star has formed the nebula dubbed Sharpless 2-106 Nebula (S106), pictured above.
A large disk of dust and gas orbiting Infrared Source 4 (IRS 4), visible in dark red near the image center, gives the nebula an hourglass or butterfly shape. S106 gas near IRS 4 acts as an emission nebula as it emits light after being ionized, while dust far from IRS 4 reflects light from the central star and so acts as a reflection nebula.
Detailed inspection of images like the above image has revealed hundreds of low-mass brown dwarf stars lurking in the nebula’s gas. S106 spans about 2 light-years and lies about 2000 light-years away toward the Cygnus constellation.
Dusty Reflections in the Scorpion’s Claws
Between the claws of the dreaded scorpion imagined by the ancient Greeks lies this giant dust cloud, imaged by the WISE space telescope. The constellation of Scorpius is prominent in the summer night sky in North America. In visible light, this nebula appears dark with a ghostly blue shine about it. These types of nebulae are called “reflection,” because they are reflecting the light of nearby stars. The dust within the cloud reflects mostly blue light.
However, WISE sees infrared light invisible to the eye. In infrared light, we can see the dust itself glowing rather than simply reflecting light. The green and red colors in this image show dust at different temperatures, with the green dust being warmer than the red dust. The dust is warmed by the light of nearby stars. This interstellar dust contains the heavy elements that planets are made of, and plays a major role in the creation of new stars.
The nebula, known as IC 4601, is part of a larger complex of clouds where new stars are being born. Some of the red stars in this image may in fact be baby stars wrapped in blankets of dust. Perhaps the dreaded scorpion can be thought of as rocking the baby stars to sleep.
Visible image of the Carina Nebula
Composed of gas and dust, the pictured pillar resides in a tempestuous stellar nursery called the Carina Nebula, located 7500 light-years away in the southern constellation of Carina.
Taken in visible light, the image shows the tip of the three-light-year-long pillar, bathed in the glow of light from hot, massive stars off the top of the image. Scorching radiation and fast winds (streams of charged particles) from these stars are sculpting the pillar and causing new stars to form within it. Streamers of gas and dust can be seen flowing off the top of the structure.
Hubble’s Wide Field Camera 3 observed the Carina Nebula on 24-30 July 2009. WFC3 was installed aboard Hubble in May 2009 during Servicing Mission 4. The composite image was made from filters that isolate emission from iron, magnesium, oxygen, hydrogen and sulphur.