NGC 2371/2


When astronomers first studied this object, they thought they were seeing two, so the two lobes of this planetary nebula were cataloged as NGC 2371 and NGC 2372. Now, the object is often called NGC 2371/2. NGC 2371/2 formed when a Sun-like star reached the end of its life and blew off its outer layers, shedding gas and dust and pushing material out into space to leave a dying, superheated star. That remnant is the bright star between the two lobes at the middle of the image.

Image Credit: NASA / ESA

The Fine Ring Nebula


Fine Ring NebulaThis is the Fine Ring Nebula, an unusual planetary nebula. Planetary nebulae form after some dying stars that have expanded into a red giant phase eject a shell of gas as they evolve into the next phase of their stellar evolution, white dwarfs. Most planetary nebulae are either spherical or elliptical in shape, or bipolar (featuring two symmetric lobes of material), but the Fine Ring Nebula looks like an almost perfectly circular ring. Astronomers believe that this unusually shaped planetary nebula was formed from a binary system. The interaction between the primary star and its orbiting companion shapes the ejected material.

The stellar object at the center of the Fine Ring Nebula does appear to be a binary system, orbiting with a period of 2.9 days. Observations suggest that the binary pair is almost perfectly face-on from our vantage point, implying that the planetary nebula’s structure is aligned in the same way. Our point of view looks down on the torus (doughnut shape) of ejected material, leading to the strikingly circular ring shape in the image.

Image Credit: ESO

Making a White Dwarf


NGC 40 is one of a class of objects called planetary nebulas, so-called because they look like the disk of a planet when viewed with a small telescope. This composite X-ray (blue)/optical (red) image of the nebula NGC 40 shows that it is a bubble of hot gas around a dying Sun-like star. In another 30,000 years or so, the nebula will dissipate, leaving behind a smallt, ultradense white dwarf star about the size of Earth.

Image Credit: X-ray—NASA / CXC  / RIT / J.Kastner & R.Montez.; Optical—NSF / AURA / NOAO / WIYN

The Helix Nebula


Stars like our Sun end their lives by casting off their outer layers, briefly forming a spectacular “planetary nebula” like the Helix Nebula.  This brief video fades between images taken at different wavelengths which show different aspects of the nebula. Optical: Hot gas ejected from a dying star glows. Near-Infrared: Near-infrared light reveals cooler material. Mid-far-Infrared: Warm dust is identified in mid-infrared light. Infrared-Ultraviolet: The ultraviolet light traces the hot gas being expelled from the dying star.

Video Credit: STScI

Looking Back at Us?


This is the planetary nebula NGC 3918, a brilliant cloud of colorful gas in the constellation of Centaurus, roughly 4,900 light-years from Earth. In the center of the cloud of gas lies a tiny star, the dying remnant of a red giant. When such a star dies, huge clouds of gas are ejected from its surface before collapses to become a white dwarf. Intense ultraviolet radiation from the tiny remnant star causes the surrounding gas cloud to glow.

NGC 3918 has a distinctive eye-like shape with a bright inner shell of gas and a more diffuse outer shell that extends far from the nebula and looks as if it could be the result of two separate irruptions of gas. However, studies of the object suggest that the two cloud components were formed at the same time but are being blown from the star at different speeds. The powerful jets of gas emerging from the ends of the large structure are estimated to be shooting away from the star at speeds of up to 350,000 km/h/

Image Credit: ESA / NASA