Bubble Nebula: The Alluring Beauty in the Sky

Object NGC 7635, also known as the Bubble Nebula, is visible from the Northern hemisphere. Scientists believe that the Bubble Nebula was formed approximately four million years ago. 

The Bubble Nebula is located in the Cassiopeia constellation, approximately 7,100 light years from earth. Scientists predict that this eye-popping nebula will explode into a SuperNova in the next ten to twenty million years.  

The Bubble Nebula is visible through hobbyist-level telescopes.  

the Bubble Nebula
Image Credit: Astronomy Magazine

Emission Nebula: What is it?

The Bubble Nebula is an emission Nebuba. Nearby stars’ intense ultraviolet radiation ionizes the Bubble Nebulas’ interstellar gases. Hydrogen atoms inside the Bubble Nebula have split apart after being struck by the intense UV rational. Through the splitting process, electrons are released as photons. 

The photons are visible at optical wavelengths, and we can image clouds, pillars, lights, and even floating bubbles in the space between stars. 

bubble nebula
Image credit: NASA Hubblesite

The Bubble Nebula Details

  • Name(s):
    • NGC 7635
    • Bubble Nebula (WFC3)
    • Sharpless 162
    • Caldwell 11
  • Type: Emission Nebula
  • Constellation: Cassiopeia
  • Distance: 7,100 light-years 
  • Age: 4 million years

When was the Nebula Discovered?

The Bubble Nebula was discovered in 1787 by William Herschel, the German-born British astronomer, and composer. 

In addition to publishing multiple catalogs of nebulae (approximately 7,500 objects), Herschel discovered Uranus, built his telescopes, conducted many deep sky surveys, found infrared radiation in sunlight, and composed numerous symphonies, concertos, sonatas, and violin solos. 

Herschel’s works and observations earned him an appointment by Britain’s King George III as a Court Astronomer. He was also the first president of the Royal Astronomical Society.

Where is the Bubble Nebula?

Officially designated Object NGC 7635, the Bubble Nebula is also called Sharpless 162 or Caldwell 1. It resides in the Northern hemisphere, about 7,100 light-years away in the Cassiopeia constellation. 

Cassiopeia has several dark sky objects that make great astrophotography targets.

What Lies Near the Bubble Nebula?

The Bubble Nebula lies close to the star cluster Messier 52, which you can view with binoculars. It has a magnitude of 5.0 and is approximately 5,000 light-years away.

Additionally, it resides near some other wondrous nebulae, so you can expect a fantastic night of capturing star images.

  • Lobster Claw Nebula
  • Pacman Nebula
  • Heart Nebula
  • Soul Nebula

Can You See the Bubble Nebula From Your Backyard?

With an eight or ten-inch telescope, the nebula is faintly visible from a dark sky area but probably from only a few remote-area backyards. Its distance of 7,100 light-years away makes viewing the Bubble Nebulae difficult except in dark sky areas during the Fall months. Crisp, clear dark sky nights in August, September, and October are best for shooting images of the Bubble Nebula. 

Image Credit: NASA

View and image the Nebula 

Astronomy is especially fun when we can look at the night sky from our backyard! 

There are two different methods to view the Bubble Nebula from your backyard.

  1. Telescope only-Viewing the Bubble Nebula through the eyepiece but not attempting to image the nebula. A reasonable expectation is that you’ll see a bright spot in your eyepiece but only a little resolution beyond that.
  2. Astrophotography-Viewing the night skies and capturing digital images. Astrophotography is separated into planetary and deep-sky imaging.
    1. Planetary-Shorter image capture times, more light is available to capture. You can view and capture “reasonable” images with an altazimuth mount on your telescope.
      1. You will likely only see the nebula as a faint shell around a bright star through a telescope.
      2. Cost is free if you already own a telescope!
    2. Deep Sky-The light is much dimmer, so much longer image capture times are required. Deep sky imaging requires an equatorial mount.
      1. Long-exposure images from your camera will reward your patience. 
      2. Plan for long exposures of up to six (or eight) hours to capture pictures of the Bubble Nebula. 
      3. The captured images will need to be processed with software.  
      4. Equatorial mounts and deep sky cameras are costly. 
      5. A few essential questions before you start collecting deep sky images:
        1. How will you power the telescope?
        2. How will you power your laptop?
        3. Which telescope filters will you use? Different filters will allow you to combine images of the bubble, images of the gas, and images of the dust fingers. Stack them together into one image, and you’ll have stunning pictures.
        4. Most important: Where will you go to the bathroom?

How Did the Bubble Nebula Form?

The Bubble Nebula’s central star creates stellar winds raging at more than four million miles per hour. The star’s powerful radiation outflow sweeps up the gases in front of it, pushing them forward. It’s like a snow plow building up snow as it presses through. The gasses pile up before the star, forming the bubble’s outer edge. 

As the bubble expands, it slams into colder gasses on its outer side. So even though the star blows gas and dust in every direction, the nebula still grows off-center.

Additionally, you can see dust-filled pillars of hydrogen gas through the transparent bubble. In the image below, they appear yellow-colored from the combined light of nitrogen and hydrogen gasses, while the heated oxygen near the star is blue. These yellow gas “fingers” form when the radiation eats into the gas layers.

The Central Star’s Power

The central star’s radiation and solar winds carve the nebula’s gas, sometimes creating pillars and fingers like the yellow formations below. Yet sometimes, a star’s forces create a vast, floating molecular bubble, as seen in the Bubble Nebula.

The magenta spot in the image below is the star and creator of the Bubble Nebula, BD+60°252 (also called SAO 20575.) The nebula’s gas and dust bubble gets shaped by this vast O 6.5 star, whose mass is 45 times that of the sun. 

How Bright is the Bubble Nebula?

The Bubble Nebula is forty-five times larger than our sun but shines in at 1,000,000 times its brightness. Can you even imagine the brightness level? One million times brighter than the sun is hard even to wrap your head around. 

How Old is the Bubble Nebula?

Scientists believe the Bubble Nebula’s formation took about four million years – the age of its star. During that time, the stellar winds pushed around the hot and cold gasses, gradually forming the bubble around the nebula’s central star, BD+602522. 

Because of the varying levels of dust, gas, and radiation buildup, some areas of the bubble have a thicker density than other sections. However, scientists say the star has lost most of its hydrogen layer and is now fusing helium into heavier elements. 

They estimate that the entire structure will explode as a supernova within ten to twenty million years. The transition into a supernova will be quick. The slowly-built bubble will finally “pop,” and the Bubble Nebula will no longer exist.

NASA picture of bubble nebula
Image Credit: NASA from a ground telescope at Kitt Peak National Observatory


At 4 million years old, the Bubble Nebula’s central star shines a million times brighter than the sun. This vast, floating space bubble dances through interstellar space, capturing our imaginations along its way.

If the bubble Nebula has peaked your interest, check out our recommendations for space documentaries on that go into detail on other amazing space topics!