Stellar Nurseries: the Nebulae Shaping New Worlds

The Dumbbell Nebula, also known as Messier 27, was the first planetary nebula ever discovered, catalogued by French astronomer Charles Messier in 1764. In this infrared image from the Spitzer Space Telescope, the nebula glows with wavelengths of light invisible to the human eye, revealing temperature structures and chemical compositions that optical images cannot show. The central star — a white dwarf at roughly 85,000 degrees Celsius — has shed nearly half of its original mass into the surrounding shells of gas over the past few thousand years.

The Ant Nebula (Mz 3) may be one of the most appropriately named objects in astronomy: its twin lobes of ejected gas really do resemble a giant ant seen from above. What makes this planetary nebula scientifically significant is what it suggests about the mechanism producing its precise, bipolar symmetry. A single dying star cannot easily explain such perfect bilateral structure — most astronomers believe a binary companion star is shaping the outflow. In roughly five billion years, our own Sun will eject its outer layers in a similar fashion, though whether it too has a binary companion to sculpt its death is an open question.

Deep within the Orion Nebula — the nearest stellar nursery to Earth, just 1,300 light-years away — Hubble found a young star with a spectacular bow shock ahead of it, like the wake ahead of a ship cutting through water. The star is moving through the nebula at roughly 200,000 kilometres per hour, and its fast stellar wind is colliding with the slower-moving gas of the nebula, producing the arc-shaped shock wave visible here. The Orion Nebula contains hundreds of newly formed and still-forming stars of all masses, making it the best natural laboratory in the sky for studying the process of star formation.

The Helix Nebula, at just 650 light-years distance, is the closest example of a planetary nebula to Earth — which is why it appears so large in the sky, nearly half the apparent diameter of the full Moon. Its nickname "the Eye of God" reflects the uncanny resemblance of its central blue iris and surrounding translucent rings to a human eye. The GALEX ultraviolet image shown here reveals the hot central white dwarf and the concentric rings of gas at different temperatures, a cross-section of the layered structure produced when a sun-like star sheds its outer atmosphere over thousands of years.

The Twin Jet Nebula (PN M2-9) is a bipolar planetary nebula formed by two stars in a binary orbit at its centre — one of them a white dwarf, the other a red giant companion. As gas is expelled from the system, the orbital dynamics of the binary constrain it into two symmetrical lobes expanding outward at more than 200 kilometres per second. Studies have shown the nebula is growing over time; measurements of the rate of expansion allow astronomers to calculate that the current phase of mass ejection began about 1,200 years ago — when the Song Dynasty ruled China and the Crusades were just beginning in Europe.

The 30 Doradus Nebula, also called the Tarantula Nebula, sits in the Large Magellanic Cloud galaxy and is the largest known star-forming region in the Local Group of galaxies. If it were as close to Earth as the Orion Nebula, it would cast shadows on the ground. Hubble's Wide Field and Planetary Camera 2 captured this sweeping panorama of its sculpted gas structures, showing thousands of newly formed stars whose radiation and stellar winds are carving cavities and columns in the surrounding material. Some of the stars at the nebula's centre, in the cluster R136, are among the most massive and luminous stars known — each more than a hundred times the mass of the Sun.

The Trifid Nebula (Messier 20) is one of the most photogenic objects in the summer sky, a rare combination of three different types of nebulae in a single region: an emission nebula glowing red from hydrogen gas ionised by a central hot star, a reflection nebula glowing blue from dust scattering starlight, and a dark nebula of opaque dust lanes dividing the emission region into three lobes — hence the name "Trifid." This 2MASS near-infrared mosaic reveals the full extent of the star-forming complex including regions invisible in optical light.

In the Large Magellanic Cloud, the N44C nebula produces softly glowing filaments of gas streaming from hot young stars in structures that, with no stretch of the imagination, recall Botticelli's famous depiction of the birth of Venus. The nebula is part of a larger complex of star-forming regions in the Magellanic Cloud, and Hubble's resolution allows individual ionised filaments to be traced back to their sources — hot O-type stars whose ultraviolet radiation is slowly evaporating and sculpting the surrounding material into these delicate streamers.

The Ghost Head Nebula (NGC 2080) in the Large Magellanic Cloud is named for the two bright white "eyes" of hot gas visible in this Hubble image, but what strikes most viewers is the vivid contrast of green and red emission against the black of space. The green comes from ionised oxygen at extremely high temperatures; the red from hydrogen. The two bright regions are separate pockets of recent star formation, each centred on a group of newly born massive stars whose radiation has cleared away the surrounding gas and dust, creating the glowing cavities that produce the ghost-like appearance.

The Dumbbell Nebula, also known as Messier 27, was the first planetary nebula ever discovered, catalogued by French astronomer Charles Messier in 1764. In this infrared image from the Spitzer Space Telescope, the nebula glows with wavelengths of light invisible to the human eye, revealing temperature structures and chemical compositions that optical images cannot show. The central star — a white dwarf at roughly 85,000 degrees Celsius — has shed nearly half of its original mass into the surrounding shells of gas over the past few thousand years.

The Ant Nebula (Mz 3) may be one of the most appropriately named objects in astronomy: its twin lobes of ejected gas really do resemble a giant ant seen from above. What makes this planetary nebula scientifically significant is what it suggests about the mechanism producing its precise, bipolar symmetry. A single dying star cannot easily explain such perfect bilateral structure — most astronomers believe a binary companion star is shaping the outflow. In roughly five billion years, our own Sun will eject its outer layers in a similar fashion, though whether it too has a binary companion to sculpt its death is an open question.

Deep within the Orion Nebula — the nearest stellar nursery to Earth, just 1,300 light-years away — Hubble found a young star with a spectacular bow shock ahead of it, like the wake ahead of a ship cutting through water. The star is moving through the nebula at roughly 200,000 kilometres per hour, and its fast stellar wind is colliding with the slower-moving gas of the nebula, producing the arc-shaped shock wave visible here. The Orion Nebula contains hundreds of newly formed and still-forming stars of all masses, making it the best natural laboratory in the sky for studying the process of star formation.

The Helix Nebula, at just 650 light-years distance, is the closest example of a planetary nebula to Earth — which is why it appears so large in the sky, nearly half the apparent diameter of the full Moon. Its nickname "the Eye of God" reflects the uncanny resemblance of its central blue iris and surrounding translucent rings to a human eye. The GALEX ultraviolet image shown here reveals the hot central white dwarf and the concentric rings of gas at different temperatures, a cross-section of the layered structure produced when a sun-like star sheds its outer atmosphere over thousands of years.

The Twin Jet Nebula (PN M2-9) is a bipolar planetary nebula formed by two stars in a binary orbit at its centre — one of them a white dwarf, the other a red giant companion. As gas is expelled from the system, the orbital dynamics of the binary constrain it into two symmetrical lobes expanding outward at more than 200 kilometres per second. Studies have shown the nebula is growing over time; measurements of the rate of expansion allow astronomers to calculate that the current phase of mass ejection began about 1,200 years ago — when the Song Dynasty ruled China and the Crusades were just beginning in Europe.

The 30 Doradus Nebula, also called the Tarantula Nebula, sits in the Large Magellanic Cloud galaxy and is the largest known star-forming region in the Local Group of galaxies. If it were as close to Earth as the Orion Nebula, it would cast shadows on the ground. Hubble's Wide Field and Planetary Camera 2 captured this sweeping panorama of its sculpted gas structures, showing thousands of newly formed stars whose radiation and stellar winds are carving cavities and columns in the surrounding material. Some of the stars at the nebula's centre, in the cluster R136, are among the most massive and luminous stars known — each more than a hundred times the mass of the Sun.

The Trifid Nebula (Messier 20) is one of the most photogenic objects in the summer sky, a rare combination of three different types of nebulae in a single region: an emission nebula glowing red from hydrogen gas ionised by a central hot star, a reflection nebula glowing blue from dust scattering starlight, and a dark nebula of opaque dust lanes dividing the emission region into three lobes — hence the name "Trifid." This 2MASS near-infrared mosaic reveals the full extent of the star-forming complex including regions invisible in optical light.

In the Large Magellanic Cloud, the N44C nebula produces softly glowing filaments of gas streaming from hot young stars in structures that, with no stretch of the imagination, recall Botticelli's famous depiction of the birth of Venus. The nebula is part of a larger complex of star-forming regions in the Magellanic Cloud, and Hubble's resolution allows individual ionised filaments to be traced back to their sources — hot O-type stars whose ultraviolet radiation is slowly evaporating and sculpting the surrounding material into these delicate streamers.

The Ghost Head Nebula (NGC 2080) in the Large Magellanic Cloud is named for the two bright white "eyes" of hot gas visible in this Hubble image, but what strikes most viewers is the vivid contrast of green and red emission against the black of space. The green comes from ionised oxygen at extremely high temperatures; the red from hydrogen. The two bright regions are separate pockets of recent star formation, each centred on a group of newly born massive stars whose radiation has cleared away the surrounding gas and dust, creating the glowing cavities that produce the ghost-like appearance.