Antennae Galaxies Facts

Our universe is filled with unusual phenomenon, and one of these is a condition that NASA calls a “state of starburst.”

This condition can be seen in a Southern Hemisphere constellation and scientists believe it started around 200-300 million years ago.

Two spiral galaxies have collided and are merging while also causing their destruction.

When a galaxy experiences the burn up of all of its gases in the process of creating stars, we see the results occurring in the Antennae Galaxy.

Antennae Galaxies Profile

Also known as:NGC 4038 & NGC 4039
Type:Interacting Spirals
Tail - Tail Distance:350,000 light years
Centre - Centre Distance:30,00 light years
Distance:45 Million light years
Discovered by:William Herschel in 1785

Hydrogen is the greatest gas quantity and when it envelopes the galaxies in streams of long clouds they appear like insect antennae on either side of the collision, arching like arms.

Who Discovered the Antennae Galaxies

The Antennae Galaxy has scientific designations of NGC 4038 and NGC 4039 and is about 360,000 light-years from us. Originally discovered in 1785 by William Herschel, he realized that these were two galaxies that were colliding.

Herschel was critical in locating many celestial bodies including the fact that Uranus was a planet and not a star as previously thought.

Caroline Herschel was William’s sister as well as his assistant for quite a few of his observations in space.

Herschel was devoted to his observations and built over 400 telescopes, including the largest one that was over 40 ft long and was moveable.

Both William and Caroline Herschel are credited for the discovery of the Antennae Galaxy, which scientists now believe contains over 300 billion stars.

Getting a better view

Until the early 2000s, most telescopes weren’t strong enough to show the incredible detail in the Antennae Galaxy.

Once the Chandra X-Ray Observatory turned their attention to this galaxy they discovered that the large number of bright points that they were seeing were neutron stars, super star clusters or black holes.

Investigation into the super star clusters found that they are young stars that are grouped together due to gravity that acts to bind them.

Stars that have collapsed have remnants and these are neutron stars. Hot gases from stars that are being pulled into the black holes create a bright light due to the energy friction.

The Chandra X-Ray Observatory found that large quantities of magnesium, iron, neon, and silicon are also within the Antennae Galaxy.

They observed the collision of at least 2 supernovas and these were confirmed by the Hubble Space Telescope.

Between 1997 and 2013, the Hubble Telescope examined and photographed the Antennae Galaxy three times.

The pictures that were released show a fast moving combination of gas, stars, dust, gas clouds and light.

There is a visible “arch” that appears in bright reds, blues, and hot pink around colliding galaxies that are being pulled into the Antennae Galaxy.

Facts about Antennae

  • NGC 4038 was considered to be a barred spiral galaxy, while NGC 4039 was a larger spiral galaxy.
  • Since their merger the two galaxies are now considered to be Interacting Spiral Galaxies.
  • Scientists estimate that the collision of the two galaxies began a few hundred million light-years ago and the merger 100-300 million light-years ago.
  • When the final merger of the two galaxies happen it is thought that it will create a Giant Elliptical Galaxy.
  • The Antennae Galaxies are around 45 million light-years from Earth and reside in the Virgo Cluster.
  • The Antennae Galaxies are the closest Interacting Spirals to Earth.
  • The diameter of the Antennae Galaxies is incredibly large, extending out hundreds of thousands of light-years.
  • Each of the galaxies in the Antennae Galaxies has a black hole at its center. It is believed that once the merger is finalize, they will form a supermassive black hole.
  • The two cores of the galaxies appear in photographs as two orange blobs.
  • The cores of the Antennae Galaxies consist of old stars that are filled with dust filaments that show up as a brown color in photographs.
  • Images of the Antennae Galaxies also include a bright blue that is where stars are born and the hydrogen gas that surrounds these regions are pink.


  • What distinguishing characteristic is the reason these galaxies are called Antennae Galaxies?
    hot gas streaming around appears like insect antennae
  • What appears in Antennae Galaxy photographs as orange blobs?
    the two cores of the galaxies
  • What new classification have the two merging galaxies been given?
    Interacting Spiral Galaxies
  • What does NASA call the Antennae Galaxies condition?
    a state of starburst
  • Once the two galaxies in the Antennae Galaxies complete their merger, what kind of galaxy will be created?
    Giant Elliptical Galaxy
  • Who is given credit for discovering the Antennae Galaxies?
    William and Caroline Herschel