Before Hubble, astronomers theorized the existence of supermassive black holes, but they had no conclusive evidence. Quasars, extremely bright quasi-stellar objects in remote active galaxies, indirectly hinted at their existence, but direct evidence of supermassive black holes didn’t come until 1994 when Hubble’s Faint Object Camera observed the heart of the giant elliptical galaxy M87. Hubble’s observations found a whirlpool of hot, ionized gas orbiting the heart of the galaxy at a speed of about 1.2 million miles per hour (550 kilometers per second). Only a supermassive black hole would have the gravitational power to create a vortex of hot gas at such velocities.
![Bright, golden light in the upper-left corner. It diffuses out from the point gradually giving way to a darker background in the lower-right corner. Emanating from the bright point is a clumpy stream of white gas that stretches toward the lower-right corner.](https://science.nasa.gov/wp-content/uploads/2023/04/m87jet-jpg.webp?w=4096&format=png)
Supermassive black holes are millions to tens of billions times the mass of the Sun. A Hubble galaxy census showed that a black hole’s mass is dependent on the mass of its host galaxy’s central bulge of stars: the larger the galaxy, the larger the black hole. This close relationship may be evidence that black holes grew along with their galaxies, devouring a fraction of the galaxy’s mass and intrinsically linking the black hole to the galaxy’s evolution.
Black holes aren’t just associated with galaxies. Astronomers estimate that 100 million black holes roam the stars of our Milky Way galaxy alone. In 2022, two teams using Hubble data measured how a suspected isolated black hole’s gravity acted like a lens, warping and deflecting the light from a background star. Their measurements indicate the lensing object’s size is either a black hole or a compact neutron star.
![Four quadrants. The upper two hold images of the galaxies NGC 3377 (left) and NGC 3379 (right). The bottom left quadrant holds and image of the galaxy NGC 4486B. The lower-right quadrant shows an expanded view of NGC 4486B's center. Each image holds a bright-yellow core surrounded by more diffuse a yellow, then orange, and later red glow.](https://science.nasa.gov/wp-content/uploads/2023/04/prc97-01-jpg.webp?w=4096&format=png)
![Two images. Left: A yellow-orange, and reddish disk (looking like a doughnut) surrounded by broader white and rust colored disk. Right: A nearly edge-on rusty-colored disk the far side appearing more white.](https://science.nasa.gov/wp-content/uploads/2023/04/ngc4261-and-ngc7052-jpg.webp?w=4096&format=png)
![Left: A diffuse, white cloud that is vertically bisected by two dark dust lanes. A turquoise, vertical rectangle denotes the area that the spectrograph sampled. Right: A vertical zig-zag of colors that are green through the middle (top to bottom) and blue on the left and red on the right.](https://science.nasa.gov/wp-content/uploads/2023/04/prc97-12-jpg.webp?w=4096&format=png)
NASA; Director, Producer & Editor: James Leigh
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Explore Other Hubble Science Highlights
Learn about some of Hubble's most exciting scientific discoveries.
![Cepheid star in Andromeda galaxy (Hubble observations)](https://science.nasa.gov/wp-content/uploads/2023/04/stsci-prc11-15a-jpg.webp?w=4096&format=png)
Discovering the Runaway Universe
Our cosmos is growing, and that expansion rate is accelerating.
![Hubble Ultra Deep Field image](https://science.nasa.gov/wp-content/uploads/2023/04/hubble_ultra_deep_field_stsci-prc04-07a-jpg.webp?w=4096&format=png)
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](https://science.nasa.gov/wp-content/uploads/2023/04/hubble_opal_composite.png?w=4096&format=png)
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](https://science.nasa.gov/wp-content/uploads/2023/04/hubble-v838mon-heic0405a-jpg.webp?w=4096&format=png)
Seeing Light Echoes
Like ripples on a pond, pulses of light reverberate through cosmic clouds forming echoes of light.
![Hubble observations of Carina Nebula section](https://science.nasa.gov/wp-content/uploads/2023/04/eta-carinae-hubble20thpic-jpg.webp?w=4096&format=png)
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.](https://science.nasa.gov/wp-content/uploads/2023/04/hubble_crabnebula-jpg.webp?w=4096&format=png)
The Death Throes of Stars
From colliding neutron stars to exploding supernovae, Hubble reveals details of some of the mysteries surrounding the deaths of stars.
![depiction of gravitational lensing](https://science.nasa.gov/wp-content/uploads/2023/04/macs_j1149-2223-jpg.webp?w=4096&format=png)
Shining a Light on Dark Matter
Hubble’s observations help astronomers uncover the underlying structure of the universe.
![Thirty proplyds in a 6 by 5 grid. Each one is unique. Some look like tadpoles, others like bright points in a cloudy disk.](https://science.nasa.gov/wp-content/uploads/2021/12/hubble-orion-proplyds-heic0917aa-jpg.webp?w=4096&format=png)
Finding Planetary Construction Zones
Hubble’s sensitivity can reveal great disks of gas and dust around stars.
![Three views of Pluto. Three mottled circles in colors of yellow, grey, rusty-orange, and black.](https://science.nasa.gov/wp-content/uploads/2023/01/hubble-pluto-stsci-01evsrjcapn1afkxej1d7e1njd.png?w=4096&format=png)
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.](https://science.nasa.gov/wp-content/uploads/2021/12/hubble-antennaegalaxies-potw1345a-jpg.webp?w=4096&format=png)
![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.](https://science.nasa.gov/wp-content/uploads/2021/12/hubble-pds70b-stsci-h-p2121c-f-1280x1280-1-jpg.webp?w=4096&format=png)
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](https://science.nasa.gov/wp-content/uploads/2023/04/comet3.gif?w=4096&format=png)
Tracking Evolution in the Asteroid Belt
These conglomerates of rock and ice may hold clues to the early solar system.