Wednesday, March 7, 2007

Cosmic Pearls

Two decades ago, astronomers spotted one of the brightest exploding stars in more than 400 years.

Since that first sighting, the doomed star, called Supernova 1987A, has continued to fascinate astronomers with its spectacular light show. NASA's Hubble Space Telescope is one of many observatories that has been monitoring the blast's aftermath. The supernova is located 163,000 light-years away in the Large Magellanic Cloud.

This image shows the entire region surrounding the supernova, the most prominent feature of which is a ring with dozens of bright spots, shining like cosmic pearls. Unleashed by the stellar blast, this material is slamming into regions along the ring's inner regions, heating them up, and causing them to glow. The ring, about a light-year across, was likely shed by the star about 20,000 years before it exploded.

This image was taken in December 2006 with Hubble's Advanced Camera for Surveys.

Friday, March 2, 2007

Trifid Nebula

The Trifid Nebula, aka M20, is easy to find with a small telescope and a well-known stop in the nebula rich constellation Sagittarius. But where visible light pictures show the nebula divided into three parts by dark, obscuring dust lanes, this penetrating infrared image reveals filaments of luminous gas and newborn stars.

This spectacular false-color view is courtesy of the Spitzer Space Telescope. Astronomers have used the Spitzer infrared image data to count newborn and embryonic stars that otherwise lie hidden in the natal dust and glowing clouds of this intriguing stellar nursery.

Wednesday, February 28, 2007

Omega Nebula: Close-Up of a Stellar Nursery

Sculpted by stellar winds and radiation, these fantastic, undulating shapes lie within the stellar nursery known as M17, the Omega Nebula, some 5,500 light-years away in the nebula-rich constellation Sagittarius. The lumpy features in the dense cold gas and dust are illuminated by stars off the upper left of the image and may themselves represent sites of future star formation. Colors in the fog of surrounding hotter material indicate M17's chemical make up. The predominately green glow corresponds to abundant hydrogen, with trace sulfur and oxygen atoms contributing red and blue hues. The picture spans about 3 light-years.

Tuesday, February 27, 2007

Windblown

A fast and powerful wind from a hot young star created this stunning bubble-shaped nebula, poised on the end of a bright filament of hydrogen gas. Cataloged as N44F, the cosmic windblown bubble is seen at the left of this Hubble Space Telescope image. N44F lies along the northern outskirts of the N44 complex of emission nebulae in the Large Magellanic Cloud, a mere 160,000 light-years away.

The bright, blue, hot star itself is just below the center of the bubble. Peering into the bubble's interior, the Hubble image reveals dramatic structures, including pillars of dust, aligned toward N44F's hot central star. Reminiscent of dust pillars in stellar nurseries within our Milky Way galaxy, they likely contain young stars at their tips. Expanding into the surrounding gas and dust at about 12 kilometers, or 7.5 miles, per second, N44F is around 35 light-years across.

Io's Colorful Face

Io is a colorful place. The closest large moon of Jupiter, Io has the most volcanic activity of any moon in the solar system with its surface being completely buried in volcanic lava every few thousand years. The black and red material corresponds to the most recent volcanic eruptions and is probably no more than a few years old. This image by the automated spacecraft Galileo highlights the side of Io that always faces away from Jupiter. In this image, colors have been adjusted to enhance contrast, but are based on real composite infrared, green and violet-light images.

Saturday, February 17, 2007

Eskimo Nebula

In 1787, astronomer William Herschel discovered the Eskimo Nebula, which from the ground resembles a person's head surrounded by a parka hood. In 2000, the Hubble Space Telescope imaged the nebula that displays gas clouds so complex they are not fully understood. The Eskimo Nebula is clearly a planetary nebula, and the gas seen above composed the outer layers of a sun-like star only 10,000 years ago. The inner filaments visible above are being ejected by strong wind of particles from the central star. The outer disk contains unusual light-year long orange filaments.

Friday, February 16, 2007

Bow Tie Nebula

Planetary nebula NGC 2440 has an intriguing bow-tie shape in this stunning view from space. The nebula is composed of material cast off by a dying sun-like star as it enters its white dwarf phase of evolution. Details of remarkably complex structures are revealed within NGC 2440, including dense ridges of material swept back from the nebula's central star.

The star itself is one of the hottest known, with a surface temperature of about 200,000 kelvins. About 4,000 light-years from planet Earth toward the nautical constellation Puppis, the nebula spans more than a light-year and is energized by ultraviolet light from the central star. The false-color image was recorded using the Hubble's Wide-Field Planetary Camera 2 (WFPC2), demonstrating still impressive imaging capabilities following the failure of the Advanced Camera for Surveys.