kids encyclopedia robot

List of galaxies facts for kids

Kids Encyclopedia Facts
Galaxy scale
Size (left) and distance (right) of a few well-known galaxies put to scale

Galaxies are huge groups of stars, dust, and gas all held together by gravity. Our own home, the Solar System, is part of a galaxy called the Milky Way.

Scientists believe there are about 51 galaxies in our local neighborhood, called the Local Group. In a bigger area called the Local Supercluster, there are around 100,000 galaxies. And in the entire observable universe, there might be as many as 100 billion galaxies!

For a long time, people didn't know that galaxies were separate from other cloudy objects in space, called nebulae. But in the 1920s, scientists figured out that galaxies are indeed their own huge star systems.

To keep track of all these galaxies, astronomers create big lists. In the 1960s, some of the first major lists were made, like the Catalogue of Galaxies and Clusters of Galaxies, which had almost 30,000 entries. Today, projects like Galaxy Zoo let people help classify over a million galaxy images!

Galaxies don't have simple names like "Galaxy One." Instead, they are usually named after the sky survey or project that found them. For example, you might see names like HUDF, SDSS, or NGC.

Famous Galaxies and Their Names

Many galaxies are known by special names, not just catalog numbers. These names often come from how they look or who discovered them.

Image Galaxy Constellation Why it's named that Cool facts
Andromeda Galaxy (with h-alpha).jpg Andromeda Galaxy Andromeda Named after the constellation it's in. This is the closest big galaxy to our Milky Way. It's expected to crash into the Milky Way in about 4.5 billion years! They will merge into a new galaxy called Milkdromeda.
Antennae Galaxies reloaded.jpg Antennae Galaxies Corvus They look like an insect's antennae. These are two galaxies that are currently crashing into each other.
NGC 4622HSTFull.jpg Backward Galaxy Centaurus It seems to spin backwards, with its spiral arms pointing in the direction of rotation.
NGC2537 - SDSS DR14.jpg Bear Paw Galaxy Lynx It looks like a bear's claw. Also called "Bear Claw Galaxy."
Blackeyegalaxy.jpg Black Eye Galaxy Coma Berenices It has a dark band of dust that looks like a "black eye" in front of its bright center. Also known as "Sleeping Beauty Galaxy."
Messier 81 HST.jpg Bode's Galaxy Ursa Major Named after Johann Elert Bode, who found it in 1774. This is the largest galaxy in the M81 Group. It has a supermassive black hole that's 70 million times bigger than our Sun!
Cartwheel Galaxy.jpg Cartwheel Galaxy Sculptor It looks like a spoked cartwheel. This is the biggest galaxy in its group, which has four spiral galaxies.
M82 HST ACS 2006-14-a-large web.jpg Cigar Galaxy Ursa Major It looks like a cigar. Also known as Messier 82 or M82.
Circinus Galaxy.png Circinus Galaxy Circinus Named after the Circinus constellation where it is found.
CometGalaxy.jpg Comet Galaxy Sculptor It looks like a comet with a long tail. Its comet-like shape is caused by a nearby galaxy cluster pulling on it.
NGC 6872 and IC 4970 by ESO VLT.jpg Condor Galaxy Pavo Named after a condor, a very large bird. This is the largest known spiral galaxy, stretching over 665,300 light-years wide. A smaller galaxy is pulling on its shape.
Eso1524aArtist’s impression of CR7 the brightest galaxy in the early Universe.jpg Cosmos Redshift 7 Sextans Its name comes from a measurement called Redshift (z) which is almost 7. This galaxy is one of the brightest and most distant galaxies ever found. It might contain some of the very first stars that created the chemical elements needed for planets and life.
NGC 6946.jpg Fireworks Galaxy Cygnus and Cepheus It looks bright and spotty, like fireworks. This is a very active galaxy where many new stars are forming.
Hoag's object.jpg Hoag's Object Serpens Caput Named after Art Hoag, who discovered this ring galaxy. This galaxy is a special type of ring galaxy.
Large.mc.arp.750pix.jpg Large Magellanic Cloud Dorado/Mensa Named after Ferdinand Magellan, a famous explorer. This is the fourth-largest galaxy in the Local Group. It's a close neighbor to our Milky Way.
Malin1-HLA (cropped).jpg Malin 1 Coma Berenices Discovered and named by David Malin. This is a very spread-out galaxy, making it hard to see.
Merging galaxies NGC 4676 (captured by the Hubble Space Telescope).jpg Mice Galaxies Coma Berenices They look like two mice with long tails. These are two galaxies that are crashing into each other.
Small Magellanic Cloud (Digitized Sky Survey 2).jpg Small Magellanic Cloud Tucana Named after Ferdinand Magellan. This is another close neighbor to our Milky Way, forming a pair with the Large Magellanic Cloud.
Hubble Interacting Galaxy Arp 148 (2008-04-24).jpg Mayall's Object Ursa Major Named after Nicholas Mayall, who discovered it. This strange object is likely two galaxies crashing into each other.
ESO-VLT-Laser-phot-33a-07.jpg Milky Way Sagittarius (center) It looks like a band of milky light across the night sky from Earth. This is our home galaxy! It contains our Sun and Solar System, including Earth.
Needle Galaxy 4565.jpeg Needle Galaxy Coma Berenices It looks long and thin, like a needle. Also known as Caldwell 38.
NASA-PeekabooGalaxy-20221206.png Peekaboo Galaxy Hydra It was hidden behind a bright star and only became visible when the star moved away. This galaxy is very old and has very few heavy elements, making it special.
M101 hires STScI-PRC2006-10a.jpg Pinwheel Galaxy Ursa Major It looks like a pinwheel (toy). Also known as Messier 101 or M101.
Sculptor Galaxy up Close.jpg Sculptor Galaxy Sculptor Named after its location in the Sculptor constellation. It's also called the Silver Dollar or Silver Coin Galaxy because it looks light and round. Also known as the Silver Coin, Silver Dollar Galaxy or Caldwell 65.
M104 ngc4594 sombrero galaxy hi-res.jpg Sombrero Galaxy Virgo It looks like a sombrero hat. Also known as Messier Object 104 or M104.
Messier 83 (captured by ESO's 1.5-metre Danish telescope).jpg Southern Pinwheel Galaxy Hydra It looks like the Pinwheel Galaxy but is in the southern part of the sky.
Messier 63 GALEX WikiSky.jpg Sunflower Galaxy Canes Venatici It looks like a sunflower.
UGC 10214HST.jpg Tadpole Galaxy Draco It looks like a tadpole with a long tail. Its tail was formed when another galaxy pulled on it during a close encounter.
TriangulumGalaxy-HighRez-Hubble-20190111.png Triangulum Galaxy Triangulum Named after its location in the Triangulum constellation.
Messier51 sRGB.jpg Whirlpool Galaxy Canes Venatici It looks like a whirlpool because of how its arms are twisted.

Important Discoveries About Galaxies

Scientists have made many exciting discoveries about galaxies over time. Here are some of the firsts:

First Galaxy Constellation Year What was special about it
First spiral galaxy Whirlpool galaxy Canes Venatici 1845 Lord William Parsons was the first to see its spiral shape, even though he didn't know it was a separate galaxy yet.
Idea of a galaxy Milky Way Galaxy and Andromeda galaxy Sagittarius (center) and Andromeda 1923 Edwin Hubble proved that the Milky Way and the Andromeda nebula were two separate galaxies, not just clouds within our own.
First radio galaxy Cygnus A Cygnus 1951 This was the first "radio star" (a strong source of radio waves) that was identified as a distant galaxy.
First quasar 3C273 Virgo 1962 3C273 was the first quasar whose distance could be measured. Quasars are super bright centers of galaxies.
First super-fast galactic jet 3C279 Virgo 1971 This galaxy shoots out a jet of material that appears to move faster than light (though it's an optical illusion).
First low-surface-brightness galaxy Malin 1 Coma Berenices 1986 This was the first confirmed galaxy that is very spread out and faint, making it hard to see.

Closest and Farthest Galaxies

Scientists are always looking for the closest and most distant galaxies to learn more about the universe.

Closest Galaxies

5 Closest Galaxies
Rank Galaxy Distance Notes
1 Milky Way Galaxy 0 This is our home galaxy, where Earth is!
2 Canis Major Dwarf 0.025 million light-years
3 Virgo Stellar Stream 0.030 million light-years
4 Sagittarius Dwarf Spheroidal Galaxy 0.081 million light-years
5 Large Magellanic Cloud 0.163 million light-years This is the largest satellite galaxy of the Milky Way.
Nearest Galaxies by Type
Type Galaxy Year found Distance Notes
Nearest galaxy to the Milky Way Sagittarius Dwarf Spheroidal Galaxy 1994 0.070 million light-years This is the closest galaxy that everyone agrees is a galaxy.
Nearest major galaxy to the Milky Way Andromeda Galaxy always 2.54 million light-years It was first identified as a separate galaxy in 1923.

Most Distant Galaxies

Scientists use something called "redshift" to measure how far away very distant objects are. The higher the redshift number (z), the farther away the object is.

Most Distant Galaxies
Type Galaxy Year found Redshift Notes
Most distant galaxy confirmed JADES-GS-z13-0 2022 z=13.2 This is the most distant galaxy confirmed by detailed measurements as of late 2022. Its light has traveled for 13.6 billion years to reach us!
Most distant quasar QSO J0313–1806 2021 z=7.64 This is the most distant known quasar as of early 2021.
Timeline of Most Distant Galaxy Records
Galaxy Years it held the record Distance (Redshift) Notes
GN-z11 2016– z=11.09 Announced in March 2016.
EGSY8p7 2015–2016 z=8.68 Its distance was measured in August 2015.
Z8 GND 5296 2013–2015 z=7.51
IOK-1 2006–2010 z=6.96 This was the most distant object known when it was discovered.
HCM-6A 2002–2003 z=6.56 This was the first galaxy found beyond a redshift of 6.
RD1 1998 z=5.34 This was the first object found beyond a redshift of 5.
CL 1358+62 G1 & CL 1358+62 G2 1997–1998 z=4.92 These two galaxies were the most distant objects known at the time. This was the first time since 1964 that a galaxy (not a quasar) held the record for being the most distant object.
3C 295 1960– z=0.461 This was the most distant object known when its redshift was measured. It was the last non-quasar to hold this record until 1997.
LEDA 25177 1951–1960 z=0.2 This galaxy is part of the Hydra Supercluster.
NGC 7619 1929 z=0.012 Using redshift, this galaxy was the farthest measured at the time. Later that year, Edwin Hubble showed how redshift relates to distance, changing how we understand the universe.
NGC 584 1921–1929 z=0.006 At this time, scientists were still figuring out if nebulae were separate galaxies.
M104 1913–1921 z=0.004 This was the second galaxy whose redshift was measured. The first was Andromeda, which is actually moving towards us.

Galaxies by Brightness and Power

Galaxies come in all sorts of brightness levels, from super bright to very faint.

What it's known for Galaxy Details Notes
Intrinsically brightest galaxy Baby Boom Galaxy This galaxy is forming stars at an incredible rate and is located 12 billion light-years away.
Brightest galaxy to the naked eye Large Magellanic Cloud Apparent magnitude 0.6 This galaxy is very bright and easy to see in the night sky from the Southern Hemisphere.
Intrinsically faintest galaxy Ursa Major III Absolute magnitude +2.2 This galaxy is incredibly dim.
Most luminous galaxy WISE J224607.57-052635.0 As of 2015, this was the most luminous galaxy found. It gives off 10,000 times more energy than the Milky Way! Most of its light is Infrared radiation.
Brightest distant galaxy (z > 6) Cosmos Redshift 7 This galaxy is reported to be the brightest of distant galaxies. It might contain some of the very first stars that created the chemical elements needed for planets and life.

Galaxies by Mass and Density

Galaxies also vary greatly in how much stuff they contain (mass) and how tightly packed that stuff is (density).

What it's known for Galaxy Details Notes
Least massive galaxy Segue 2 ~550,000 times the mass of the Sun This tiny galaxy is held together by dark matter, not just its stars.
Most massive galaxy ESO 146-IG 005 ~30 trillion times the mass of the Sun This giant galaxy is at the center of a huge galaxy cluster.
Most dense galaxy M85-HCC1 This is an ultra-compact dwarf galaxy, meaning it's small but very packed.
Most massive spiral galaxy ISOHDFS 27 1.04 trillion times the mass of the Sun

Galaxies Living Alone

A field galaxy is a galaxy that doesn't belong to a larger group or cluster of galaxies. It's like a lone wolf in the universe, held together by its own gravity.

List of field galaxies
Galaxy Notes
NGC 4555
UGC 2885

Galaxies Interacting and Merging

Galaxies don't always stay separate. They can pull on each other with gravity, leading to amazing interactions and even mergers!

Galaxies Pulling on Each Other

These galaxies are close enough that their gravity affects each other, but they haven't fully crashed yet.

Galaxies in tidal interaction
Galaxies Notes
The Magellanic Clouds are being pulled apart by the Milky Way's gravity. This creates streams of gas and stars between them.
The smaller NGC 5195 galaxy is pulling on the larger Whirlpool Galaxy, which helps create its beautiful spiral arms.
These three galaxies are interacting, pulling out long tails of gas and dust.
Tadpole Galaxy The Tadpole Galaxy had a close encounter with another galaxy, which stretched it out and gave it a long tail.

Galaxies Crashing and Merging

Sometimes, galaxies collide and eventually merge into one bigger galaxy.

Galaxies undergoing near-equal merger
Galaxies Notes
Antennae Galaxies (NGC 4038 & NGC 4039) These two spiral galaxies are just starting to crash into each other and will eventually merge.
Butterfly Galaxies (NGC 4567 & NGC 4568) These two spiral galaxies are in the early stages of merging.
Mice Galaxies (NGC 4676, NGC 4676A & NGC 4676B) These two spiral galaxies are currently pulling on each other and merging.
NGC 2207 and IC 2163 (NGC 2207 & IC 2163) These are two spiral galaxies beginning to collide and merge.
Four galaxies in CL0958+4702 These four galaxies at the center of a galaxy cluster are in the process of merging.
Galaxy protocluster SPT2349-56 This group of 14 galaxies is located 12.4 billion light-years from Earth. Each of these galaxies is forming stars 1,000 times faster than the Milky Way!

Recently Merged Galaxies

These galaxies have recently finished merging, but you can still see signs of their past collision.

Recently merged galaxies of near-equals
Galaxy Notes
Starfish Galaxy (NGC 6240) This galaxy recently came together, and you can still see two bright centers from the original galaxies.

Galaxies Being Eaten

Sometimes, a larger galaxy can "eat" a smaller one, pulling it apart with its strong gravity.

Galaxies undergoing disintegration by cannibalization
Disintegrating Galaxy Consuming Galaxy Notes
Canis Major Dwarf Galaxy Milky Way Galaxy Our Milky Way is slowly pulling apart this dwarf galaxy.
Sagittarius Dwarf Elliptical Galaxy Milky Way Galaxy The M54 star cluster is thought to be the core of this dwarf galaxy that the Milky Way is consuming.
Objects considered destroyed galaxies
Former Galaxy Destroyer Notes
Omega Centauri Milky Way Galaxy This is now a globular cluster in the Milky Way, but it's believed to be the leftover core of a dwarf galaxy that our galaxy ate.
Gaia Sausage Milky Way Galaxy This is what's left of a dwarf galaxy that crashed into the Milky Way about 8-11 billion years ago. It was the last major merger for our galaxy.

Galaxies with Other Special Features

Some galaxies have unique features that make them stand out.

Galaxy name Constellation Special feature Notes
SDSS J081421.68+522410 Lynx Giant radio lobes Also called Alcyoneus. Its radio lobes are the largest known structures created by a single galaxy.
M87 Virgo First black hole ever imaged This galaxy is at the center of the Virgo Cluster. It contains the first black hole ever captured in an image, in 2019.
NGC 2770 Lynx "Supernova Factory" This galaxy is called a "Supernova Factory" because many supernova explosions have happened there recently.
NGC 3314 (NGC 3314a and NGC 3314b) Hydra Exact visual alignment This is a rare sight: two spiral galaxies that just happen to line up perfectly from our view, even though they are very far apart and not related.
ESO 137-001 Triangulum Australe "Tail" feature This galaxy is losing its gas as it speeds through a galaxy cluster, leaving a long "tail" where many new stars are forming. It looks like a comet!
Comet Galaxy Sculptor Interacting with a galaxy cluster This spiral galaxy is being stretched and pulled by a galaxy cluster, giving it a comet-like appearance.
Cosmos Redshift 7 Sextans Brightest distant galaxy (z > 6) This galaxy is reported to be the brightest of distant galaxies. It might contain some of the very first stars that created the chemical elements needed for planets and life.

Images for kids

See also

Kids robot.svg In Spanish: Anexo:Galaxias para niños

Lists of galaxies

kids search engine
List of galaxies Facts for Kids. Kiddle Encyclopedia.