hubble’s panorama of the carina nebula, some 7500 light years away from earth, and about fifty light years in length here. stars old and new illuminate clouds of cosmic dust and gas, like the clumping hydrogen from which they were born.
the top star seen at the bisection of the first two panels, part of the eta carinae binary star system (most stars are in binary systems), is estimated to be more than a hundred times the mass of the sun - large enough to go supernoava in about a million years.
it also produces four million times as much light as the sun, and was once the second brightest star in the night sky. but surrounding dust and gas has dimmed our view of the star, though it’s still visible in the night sky to all but those in the most light polluted cities.
the fifth panel shows ‘the mystic mountain,’ where nascent stars in the dust cloud are spewing hot ionized gas and dust at 850,000 miles an hour. eventually, the ultraviolet radiation from these stars will blow away the dust, leaving visible the stars, like the cluster seen at the top of the panel, which were formed only half a million years ago.
Most galaxies have a majestic spiral or elliptical structure. About a
quarter of galaxies, though, look quite messy. Known as irregular galaxies, this group includes NGC 5408 above.
John Herschel recorded the existence of NGC 5408 in 1834. Astronomers had long mistaken it for a planetary nebula, an expelled cloud of material from an aging star. Instead, it turned out to be an entire galaxy, located about 16 million light-years from Earth in the constellation of Centaurus (The Centaur).
In yet another sign of NGC 5408 breaking convention, the galaxy is associated with an object known as an ultraluminous X-ray source, one of the best studied of its class. These rare objects beam out
huge amounts of
energetic X-rays. Astrophysicists believe these sources to be strong candidates for intermediate-mass black holes. This hypothetical type of black hole has a good deal more mass than the black holes formed when giant stars collapse. (x)
Let’s kick off the weekend with this amazing image taken by the Hubble
Space Telescope: a glittering star cluster called Trumpler 14.
It is located 8,000 light-years away from Earth and it contains some of
the brightest stars seen in our galaxy. But, “like some Hollywood
celebrities, the stars will go out in a flash,” mentions the Space
Telescope Science Institute’s news release. Don’t worry, though, we’re
talking about “space-soon.” We still have a few million years to
observe these stars before they burn out and explode as supernovae!
The subject of this NASA/ESA Hubble Space Telescope image is known as NGC 3597. It is the product of a collision between two good-sized galaxies, and is slowly evolving to become a giant elliptical galaxy. This type of galaxy has grown more and more common as the Universe has evolved, with initially small galaxies merging and progressively building up into larger galactic structures over time.
NGC 3597 is located approximately 150 million light-years away in the constellation of Crater (The Cup). Astronomers study NGC 3597 to learn more about how elliptical galaxies form — many ellipticals began their lives far earlier in the history of the Universe. Older ellipticals are nicknamed “red and dead” by astronomers because these bloated galaxies are not anymore producing new, bluer, stars in ages, and are thus packed full of old and redder stellar populations.
Before infirmity sets in, some freshly formed elliptical galaxies experience a final flush of youth, as is the case with NGC 3597. Galaxies smashing together pool their available gas and dust, triggering new rounds of star birth. Some of this material ends up in dense pockets initially called proto-globular clusters, dozens of which festoon NGC 3597. These pockets will go on to collapse and form fully-fledged globular clusters, large spheres that orbit the centres of galaxies like satellites, packed tightly full of millions of stars.
Latest News: First discovered in the 1960s, the comet-shaped “Smith Cloud” – depicted in this artist’s illustration – is 11,000 light-years long and 2,500 light-years across. The cloud, which is invisible at optical wavelengths, is plummeting toward our galaxy at nearly 700,000 miles per hour.
Astronomers long thought that the Smith Cloud might be a failed, starless galaxy, or gas falling into the Milky Way from intergalactic space. If either of these scenarios proved true, the cloud would contain mainly hydrogen and helium, not the heavier elements made by stars.
Hubble was used to measure the chemical composition and found heavier elements that could only come from stars. The cloud appears to have been ejected from within the Milky Way and is now boomeranging back. It will plow back into the Milky Way’s disk in about 30 million years. When it does, astronomers believe it will ignite a spectacular burst of star formation, perhaps providing enough gas to make 2 million suns.
Though this settles the mystery of the Smith Cloud’s origin, it raises new questions: How did the cloud get to where it is now? What calamitous event could have catapulted it from the Milky Way’s disk, and how did it remain intact? The answers may be found in future research.
Hubble Captures a Perfect Storm of Turbulent Gases
Resembling the fury of a raging sea, this image actually shows a bubbly ocean of glowing hydrogen gas and small amounts of other elements such as oxygen and sulfur.
The photograph, taken by NASA’s Hubble Space Telescope, captures a small region within M17, a hotbed of star formation. M17, also known as the Omega or Swan Nebula, is located about 5,500 light-years away in the constellation Sagittarius. The image is being released to commemorate the thirteenth anniversary of Hubble’s launch on April 24, 1990.
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 accentuates the three-dimensional 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 photograph. The intense heat and pressure cause some material to stream away from those surfaces, creating the glowing veil of even hotter greenish 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 May 29-30, 1999, with the Wide Field Planetary Camera 2. The colors in the image represent various gases. Red represents sulfur; green, hydrogen; and blue, oxygen.
Object Names: M17, NGC 6618, Swan Nebula, Omega Nebula