Image Tour: The Bubble Nebula

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Four circles with stars inside. A line connects the circles. 

Text, The Bubble Nebula, a hubble image tour. A bright nebula. 

Text, Fast facts, Location, Constellation Cassiopeia. Distance from Earth, 7,100 light-years. Size, Nebula Size, 25 light-years across. Bubble size, 7 light-years across. 

The striking Bubble Nebula contains an ethereal orb floating in a vibrant region of luminous gas. 

Tour Stops, Nebula, central start, bubble, free expansion, constrained expansion, pillars, back pillars. Under "Tour Stops," The word "Nebula" is highlighted. 

A nebula with a bluish orb. 

Text, This wide view of the Bubble Nebula, from Kitt Peak National Observatory, shows the extent of the glowing cloud. 

The entire region is shaped by the radiation and winds from a single star inside the bubble. Central star. A single star in a bluish orb is circled. 

The orb is highlighted. 

Text, The Hubble Space Telescope captured the signature bubble in detail. 

Under "Tour Stops," the highlighting moves from "Nebula" to "Central Star." 

The orb enlarges. It has a large star surrounded by a pinkish color. There are cloud-like swirls in the orb. 

Text, The influential star, known by its catalog name of B.D. plus 60 2 5 2 2 , is very hot and very massive. It emits a tremendous amount of high-energy ultraviolet light that heats the gas of the nebula, causing it to glow. 

When it formed roughly 4 million years ago, the star was about 60 times more massive than the Sun. 

Since then, material has been slowing and steadily blowing off the star in what astronomers call a" mass-loss wind." 

Now, the star has shed a quarter of its mass and is down to 45 times the Sun's mass. 

The tour stop "Bubble" is now highlighted. 

We zoom out to the full radius of the bubble that surrounds the star. It has orange, purple, and reddish cloudlike surroundings. 

Text, The material expelled from the star has, over millions of years, expanded to form the bubble. 

The star is noticeably off-center inside the structure. A dashed vertical and horizontal line appear in the center that splits the orb into four sections. The star is in the upper-left quadrant. 

Under "Tour Stops," the highlighting moves from "Bubble" to "Free Expansion." 

The orb is enlarged. Two dashed lines highlight the bottom and right side of the orb. Text, Parts of the bubble that are moving away from the surrounding nebula expand more freely. 

Under "Tour Stops," the highlighting moves from "Free Expansion" to Constrained Expansion." 

A dash line appears on the upper and left side of the orb, and another curves from the left side inward. Text, Closer to the greater nebula, heated gas creates a pressure that inhibits the bubble's expansion. The highlighting moves from "Constrained Expansion" to "Pillars." 

Yellow cloudlike structures exist to the left of the bubble. 

Text, Pillars, gaseous pillars line the inner edge of the encompassing nebula. 

Radiation and winds from the massive star blow away low-density gas, leaving behind higher-density clumps and carving the long, thin pillar structures. Highlighting moves from "Pillars" to "Back Pillars." 

Text, Behind the bubble stands another set of pillars. 

Thick, yellowish structures. 

Our view of these pillars is like looking down on a mountain range from above. 

Condensed cloud-like swirls against a wispy bluish background. 

The highlighting disappears from "Back Pillars." There are now no words highlighted under "Tour Stops." 

Text, Hubble's view of the Bubble Nebula reveals, in great detail, the remarkable structures sculpted by the radiation and winds from a rare, massive, and energetic star. 

Slowly zooms out from the orb. The orb is brighter on the top and left. 

The screen turns black.