Behind the Images of Hubble

Light and Filters: Light from astronomical objects comes in a wide range of colors, each corresponding to a particular kind of electromagnetic wave. Hubble can detect all the visible wavelengths of light plus many more that are invisible to human eyes, such as ultraviolet and infrared light. Astronomical objects often look different in these different wavelengths of light. To record what an object looks like at a certain wavelength, Hubble uses special filters that allow only a certain range of light wavelengths through. Once the unwanted light has been filtered out, the remaining light is recorded.
Enhanced Color: Enhancing the visible colors in an image often brings out an object’s subtle structural detail.
Natural/True Color: The colors in this image of a galaxy were chosen to simulate the colors that our eyes might see if we were able to visit it in a space
Representative Color: Representative color helps scientists visualize what would otherwise be invisible, such as the appearance of an object in infrared light.

NGC 6543: The Cat’s Eye Nebula

A planetary nebula in the constellation of Draco, it is one of the most complex nebulae known, with high-resolution Hubble Space Telescope observations revealing remarkable structures such as knots, jets, bubbles and sinewy arc-like features. (X) In the center of the Cat’s Eye there is a bright and hot star; around 1000 years ago this star lost its outer envelope, producing the nebula. It was discovered by William Herschel on February 15, 1786, and was the first planetary nebula whose spectrum was investigated by the English amateur astronomer William Huggins in 1864. The results of the latter investigation demonstrated for the first time that planetary nebulae consist of hot gases, not stars.

NGC 7635: The Bubble Nebula

A H II region emission nebula in the constellation Cassiopeia, it lies close to the direction of the open cluster Messier 52. The “bubble” is created by the stellar wind from a massive hot, 8.7 magnitude young central star. The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by William Herschel.

IC 5070: The Pelican Nebula

Found in the direction of the constellation Cygnus, it is located 1,800 light-years away. The Pelican has a particularly active mix of star formation and evolving gas clouds. The light from young energetic stars is slowly transforming cold gas to hot and causing an ionization front gradually to advance outward. Particularly dense filaments of cold gas are seen to still remain. Millions of years from now this nebula might no longer be known as the Pelican, as the balance and placement of stars and gas will leave something that appears completely different. [image via]

NGC 6523: The Lagoon Nebula

Estimated to be between 4,000 to 6,000 light years from the Earth, in the direction of the Sagittarius constellation. It is classified as both an emission nebula and an HII region. The Lagoon Nebula was discovered by Guillaume Le Gentil in 1747 and is one of only two star-forming nebulae faintly visible to the naked eye from mid-northern latitudes. Seen with binoculars, it appears as a distinct oval cloudlike patch with a definite core. [image via]

NGC 6752 Stars

NGC 6752 is a globular star cluster in the direction of the southern constellation Pavo, and estimated to be 13,000 light-years away. It is the third brightest in the sky, after 47 Tucanae and Omega Centauri. [image via]

Behind the Images of Hubble: Hubble Images are Produced, Not Taken

Images must be woven together from the incoming data from the cameras, cleaned up and given colors that bring out features that eyes would otherwise miss. In this video from HubbleSite, a Hubble-imaged galaxy comes together on the screen.

Melotte 15: Within ‘The Heart’ Nebula

7500 light years away from Earth, The Heart Nebula is located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. The nebula is formed by plasma of ionized hydrogen and free electrons, and this open cluster of stars¬† contains a few bright stars nearly 50 times the mass of our Sun, and many more dim stars that are only a fraction of our Sun’s mass. The cluster used to contain a microquasar that was expelled millions of years ago. [image via]

IC 410: Emission Nebula

In the constellation Auriga, this nebula is about 12,000 light-years away and over 100 light-years wide. It is a cloud of glowing hydrogen gas, whose shape is sculpted by stellar winds and radiation from an embedded open star cluster called NGC 1893 [image via]

IC 1396: The Elephant’s Trunk Nebula

An ionized gas region located in the constellation Cepheus about 2,400 light years away from Earth; it is commonly called the Elephant’s Trunk nebula because of its appearance at visible light wavelengths, where there is a dark patch with a bright, sinuous rim. [image via]