Finding Planetary Construction Zones

Hubble’s sensitivity can reveal great disks of gas and dust around stars.

Thirty proplyds in a 6 by 5 grid. Each one is unique. Some look like tadpoles, others like bright points in a cloudy disk.

In 1992, Hubble was the first telescope to resolve protoplanetary disks (dubbed “proplyds”) around stars in the Orion Nebula. Hubble’s high resolution and sensitivity, along with the Orion Nebula’s proximity, have allowed the telescope to image proplyds around nearly 200 stars in the nebula. Proplyds are pancake-like disks of mostly gas and some dust surrounding a young star. They are a prerequisite for the formation of planetary systems.

Thirty proplyds in a 6 by 5 grid. Each one is unique. Some look like tadpoles, others like
Here are some of the many protoplanetary disks that were discovered by Hubble in the large, majestic Orion Nebula.
NASA, ESA, and L. Ricci (ESO)

Hubble has also done the largest and most sensitive visible-light imaging survey of debris disks around stars. Two particular stars highlight Hubble’s observations: TW Hydrae, and Beta Pictoris.

Using a mask to block the star’s bright light, Hubble scientists spotted a mysterious gap in a vast protoplanetary disk of gas and dust swirling around the star TW Hydrae. The gap is likely the result of a growing, unseen planet gravitationally sweeping up material and carving out a lane in the disk like a snowplow. The 1.9 billion-mile-wide gap isn’t completely cleared of material yet.

TW Hydrae Hubble observation (left) and illustration (right)
This Hubble image (left) and graphic (right) show a gap in a protoplanetary disk of dust and gas whirling around the nearby red dwarf star TW Hydrae. The gap’s presence is probably due to the effects of a growing, unseen planet that is gravitationally sweeping up material and carving out a lane in the disk. Astronomers used a masking device within the Hubble camera to block out the star’s bright light so that the disk’s structure could be seen.
NASA, ESA, J. Debes (STScI), H. Jang-Condell (University of Wyoming), A. Weinberger (Carnegie Institution of Washington), A. Roberge (Goddard Space Flight Center), G. Schneider (University of Arizona/Steward Observatory) and A. Feild (STScI/AURA)

More recently, astronomers using Hubble noticed a change in brightness with position of TW Hydrae's disk. Because Hubble has 18 years' worth of observations of the star, the astronomers could assemble a time-lapse movie of the shadow's rotation. They think an unseen planet in the disk is gravitationally pulling on material near the star and warping the inner part of the disk. The twisted, misaligned inner disk is casting its shadow across the surface of the outer disk.

four part graphic showing orange rings against black
These images, taken a year apart by NASA's Hubble Space Telescope, reveal a shadow moving counterclockwise around a gas-and-dust disk encircling the young star TW Hydrae. The two images at the top, taken by the Space Telescope Imaging Spectrograph, show an uneven brightness across the disk. Through enhanced image processing (images at bottom), the darkening becomes even more apparent. These enhanced images allowed astronomers to determine the reason for the changes in brightness. The dimmer areas of the disk, at top left, are caused by a shadow spreading across the outer disk. The dotted lines approximate the shadow's coverage. The long arrows show how far the shadow has moved in a year (from 2015-2016), which is roughly 20 degrees. Based on Hubble archival data, astronomers determined that the shadow completes a rotation around the central star every 16 years. They know the feature is a shadow because dust and gas in the disk do not orbit the star nearly that quickly. So, the feature must not be part of the physical disk. The shadow may be caused by the gravitational effect of an unseen planet orbiting close to the star. The planet pulls up material from the main disk, creating a warped inner disk. The twisted disk blocks light from the star and casts a shadow onto the disk's outer region.
NASA, ESA, and J. Debes (STScI)

Hubble researchers also studied changes in the planetary disk surrounding Beta Pictoris. By masking out the star’s light, they could detect changes in the material orbiting the star. The results point to a massive planet embedded within the star’s dust disk. Astronomers spotted the planet using the European Southern Observatory.

Hubble observations of Beta Pictoris
Hubble has given astronomers the most detailed picture to date of a large, edge-on, gas-and-dust disk encircling the 20-million-year-old star Beta Pictoris. Ongoing changes seen in the disk allow scientists to study the effect of a massive planet embedded within the orbiting material. Beta Pictoris itself is hidden by the dark spot that masks out the the bright star at the center of each image, allowing astronomers to see the disk.
NASA, ESA, and D. Apai and G. Schneider (University of Arizona)

Hubble’s ultraviolet sensitivities captured radiation falling onto a planet forming around the star PDS 70. Previous observations with ground-based telescopes revealed two massive Jupiter-sized, planets carving out a wide gap within the planetary disk of the star. Located some 370 million light-years away, the young 6-million-year-old star is slightly smaller and less massive than the Sun.

Hubble observations pinpoint planet PDS 70b.
Hubble observations pinpoint planet PDS 70b. A coronagraph on Hubble’s camera blocks out the glare of the central star for the planet to be directly observed. The team’s fresh technique for using Hubble to directly image this planet paves a new route for further exoplanet research, especially during a planet’s formative years.
NASA, ESA, McDonald Observatory–University of Texas, Yifan Zhou (UT); Image Processing: Joseph DePasquale (STScI)

Explore Other Hubble Science Highlights

Learn about some of Hubble's most exciting scientific discoveries.

Cepheid star in Andromeda galaxy (Hubble observations)

Discovering the Runaway Universe

Our cosmos is growing, and that expansion rate is accelerating.

Hubble Ultra Deep Field image

Tracing the Growth of Galaxies

Hubble is instrumental in uncovering the various stages of galactic evolution.

Hubble image left to right: Jupiter, Uranus, Saturn, Neptune

Studying the Outer Planets and Moons

Hubble’s systematic observations chart the ever-changing environments of our solar system's giant planets and their moons. 

Hubble view of an expanding halo of light around star v838 monocerotis

Seeing Light Echoes

Like ripples on a pond, pulses of light reverberate through cosmic clouds forming echoes of light.

Hubble observations of galaxies' centers

Monster Black Holes are Everywhere

Supermassive black holes lie at the heart of nearly every galaxy.

Hubble observations of Carina Nebula section

Exploring the Birth of Stars

Hubble’s near-infrared instruments see through the gas and dust clouds surrounding newborn stars.

An oval of colorful tendrils of gas and dust stretching from lower-left to upper right. Ova's outer ring is rusty-red tendrils, followed by a yellow/lime-green ring of tendrils. Oval's center is bright turquoise with white tendrils bisecting it. All set on a black background.

The Death Throws of Stars

From colliding neutron stars to exploding supernovae, Hubble has revealed new details of  some of the mysteries surrounding the deaths of stars. 

depiction of gravitational lensing

Shining a Light on Dark Matter

Hubble’s observations help astronomers uncover the underlying structure of the universe.

Three views of Pluto. Three mottled circles in colors of yellow, grey, rusty-orange, and black.

Uncovering Icy Objects in the Kuiper Belt

Hubble’s discoveries helped NASA plan the New Horizon spacecraft’s flyby of Pluto and beyond.

Comma shaped curved cloud of gases in bright white edged with bright-pink star forming regions, and threaded with rusty-brown tendrils of dust at center and throughout the comma shaped merger. All set against the black of deep space.

Galaxy Details and Mergers

Hubble’s observations reveal a menagerie of galaxies.

Blue background. Center of image is a disk blocking the light of a star. Below and just to the left of the disk, at about seven o'clock, is a bright white point. This is PDS 70b.

Recognizing Worlds Beyond Our Sun

Hubble’s unique capabilities allow it to explore planetary systems around other stars. 

animation of a binary asteroid with a shifting tail

Tracking Evolution in the Asteroid Belt

These conglomerates of rock and ice may hold clues to the early solar system.