Image Tour: Shadows in the Serpens Nebula

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Tour a Hubble Space Telescope image of the Serpens Nebula, a star-forming region with bright young stars surrounded by debris disks casting eerie shadows into the nebula.

Produced by the Space Telescope Science Institute’s Office of Public Outreach in collaboration with NASA’s Universe of Learning partners: Caltech/IPAC, Center for Astrophysics | Harvard & Smithsonian, NASA Jet Propulsion Laboratory, and Sonoma State University.

  • Hubble Space Telescope image of the Serpens Nebula (WFC3/IR): NASA, ESA, and STScI
  • Written by Margaret W. Carruthers
  • Designed by Dani Player
  • Subject matter expertise from Klaus Pontoppidan
  • Editorial and design input from Yesenia Perez, Quyen Hart, Dr. Rutuparna Das (Center for Astrophysics | Harvard & Smithsonian), Dr. Varoujan Gorjian (JPL)
  • Music courtesy of Yesh Music (ASCAP)

Read more about the Bat Shadow at


 A white-outlined box is within a gold-outlined box on top of the Serpens Nebula background. Title, The Serpens Nebula, Image Tour. A photo of a dark-blue space background is covered with swirling, gauzy white-and-brown clouds, at least eight bright stars shine through the haze. Text, Fast Facts, constellation, Serpens Cauda, distance from Earth, 1,300 light-years, wavelength of light, near-infrared. 

Text, infrared light from bright young stars in the Serpens Nebula shines through and reflects off clouds of ice, dust, and gas that make up this star-forming region. A zoomed-in view shows a bright star near a dust cloud labeled SVS 20. 

Text, Tour stops, Binary Star SVS 20. The brightest star in this region is SVS 20, a young red double-star system. A dotted line outlines the lighter-colored dust cloud that is near SVS 20. Text, SVS 20 is embedded within or just behind a dense cloud of dust. Its infrared light shines through the dust and lights up the edge of the cloud from behind. The view moves up to another bright star with two dark cone-shaped areas connected to it. 

Text, Tour stops, Star HBC 672. Roughly 0.2 light-years away from SVS 20 is another bright object, a Sun-like star known as HBC 672. Like the other stars in this region, HBC 672 is very young, just a couple of million years old, and is still in the process of forming. 

Surrounding the star is a circumstellar disk, a donut-shaped ring of dust, over time this material will likely clump together to form planets, moons, asteroids, and comets. 

Tour stops, Great Bat Shadow, HBC 672's debris disk is much too small, faint, and far away to see, even for Hubble. Two diagonal dotted lines cross through HBC 672. Text, These dark wing-shaped structures are actually shadows of the disk projecting out into the nebula. The "Great Bat Shadow" spans roughly 200 times the diameter of our solar system. It is tens to hundreds of times larger than the disk itself. The debris disk acts like a lampshade, above and below. The starlight is unobstructed and shines freely out into the clouds. Astronomers can study the shadow to find out what the disk is made of and to understand the larger nebula. Debris disks are common around young stars, but the combination of an edge-on viewing angle and a nebula "screen" to project the shadow onto is rare. 

Tour Stops, Lesser Bat Shadow, the view moves to the left of HBC 672, a dimmer star shines through dust clouds and two diagonal dotted lines pass through the center of the light area. Text, in spite of their rarity, a smaller similar-looking shadow emanates from another young star in the same region not far away. Scientists think that star-and-debris-disk systems like these may resemble our own solar system when it began to form more than 4.5 billion years ago.