Huge blue eyes in the universe

Hubble Space Telescope captures a stunning picture of an eye-like nebula on May 4.

Eye-shaped nebula in the universe.Such nebula-like nebulae are rare in the universe.Photo: NASA.

The aforementioned nebula is a colorful cloud of gas dust called Kohoutek 4-55, which has an "eye" facing the Hubble space telescope. The picture was taken with Hubble's No. 2 wide-angle camera. This is one of the last photos of this camera, because it is about to be replaced with the 3rd wide-angle camera in the next few days. NASA's Atlantis space shuttle leaves the launch pad yesterday to perform one of the most dangerous missions in orbit: Hubble telescope repair and maintenance.

Nebula is a mixture of dust, hydrogen gas, helium and plasma gas. They are often concentrated in narrow strips, ranging from a few tens to several hundred light years (1 light year = 9.460 billion km). The nebula has no relationship with the planet. They are called "nebulae" because when viewed with the first generation telescopes, they look like planets in the solar system. The galaxy has many nebulae. The "eye" in the picture consists of many physical layers of a red giant star. The star blows material layers into space before dying.

Ultraviolet radiation from the star's remaining hot core penetrates the outer layers of the gas, making them glow. The floor of the dust and gas glows brightly surrounded by a pale red halo. Each color is created by the radiation of a gas, such as nitrogen (red), hydrogen (green), oxygen (blue). Astronomers claim that nebulae with such multiple layers are relatively rare in the universe.