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Our galactic neighborhood

The Milky Way is one galaxy among hundreds of billions — and it is not even the largest in its own small cluster. These are the Local Group neighbours closest to home, from giant spirals to the dwarf companions caught in their gravity.

The Local Group

Neighbours, drawn together. Tap a galaxy in the diagram to read its identity and distance.

Schematic · not to scale
Milky WayAndromedaM32M110TriangulumLarge Magellanic CloudSmall Magellanic CloudNOT TO SCALE · POSITIONS ILLUSTRATIVE
Spiral · Spiral galaxy

Andromeda Galaxy

M31 · nearest large spiral

Distance~2.5 million light-years
Diameter~220,000 light-years

The nearest large galaxy to our own, tilted towards us so its spiral structure is clear. At 2.5 million light-years it is the most distant object most people can see without a telescope — a faint smudge in the constellation Andromeda.

Read the full entry

Schematic only. Positions, separations and sizes are compressed and rearranged to make the relationships readable. The Milky Way and Andromeda are about 2.5 million light-years apart, while M32 sits only about 2.5 million light-years from us too — because it orbits Andromeda, not us.

Our Galactic Neighborhood

Member by member

Distances in light-years. Galaxies are labelled by type, not by size on the page.

Spiral · 01
Barred spiral galaxy

The Milky Way

Our home galaxy

A flat, rotating disk of gas, dust and stars with a bright central bar. We cannot photograph it from outside — every all-sky portrait like this one is an artist's reconstruction built from measurements of our own position inside it.

Distance
0 — we are inside it
Diameter
~100,000 light-years
Stars
100–400 billion
Galactic year
~230 million years
  • The Sun orbits the centre about once every 230 million years; at 4.6 billion years old it has completed roughly 20 laps.
  • A supermassive black hole called Sagittarius A* anchors the centre, with about 4.3 million times the Sun's mass.
  • The bright band across a dark sky is the disk seen edge-on from inside — we are looking along the plane of our own galaxy.
  • Its two brightest companions, the Large and Small Magellanic Clouds, are visible to the naked eye from the southern hemisphere.
NASA Science — Galaxies
Spiral · 02
Spiral galaxy

Andromeda Galaxy

M31 · nearest large spiral

The nearest large galaxy to our own, tilted towards us so its spiral structure is clear. At 2.5 million light-years it is the most distant object most people can see without a telescope — a faint smudge in the constellation Andromeda.

Distance
~2.5 million light-years
Diameter
~220,000 light-years
Stars
~1 trillion
Approaching at
~110 km per second
  • Its stellar disk is roughly twice as wide as the Milky Way's, and it holds several times as many stars.
  • It is falling towards us: in about 4.5 billion years the two spirals will merge into a single, larger elliptical galaxy.
  • Two small satellite galaxies, M32 and M110, appear beside it in most telescope views.
  • Its light left 2.5 million years ago — before our species existed — and arrived at your eye tonight.
NASA — Hubble Messier catalog M31
Satellite · 03
Dwarf elliptical galaxy

M32

NGC 221 · Andromeda's compact companion

A dense little elliptical galaxy sitting just 16 arcminutes from M31's core. It looks featureless through a telescope, but its compact, unusually heavy centre hints that Andromeda has stripped away much of its outer mass.

Distance
~2.5 million light-years
Diameter
~6,500 light-years
Type
Compact elliptical (cE2)
Discovered
1749, Guillaume Le Gentil
  • It was the first dwarf elliptical galaxy ever recognised, though for two centuries it was simply catalogued as a companion of M31.
  • A supermassive black hole of roughly 2.5 million solar masses sits at its centre — proportionally enormous for such a small galaxy.
  • Only about 2.5 billion stars are packed into its 6,500 light-years, in a population almost entirely older than the Sun.
  • Its outer layers may have been pulled away by Andromeda; the stars we see could be the surviving core of a once-larger galaxy.
NASA — Hubble Messier catalog M32
Satellite · 04
Dwarf elliptical galaxy

M110

NGC 205 · Andromeda's second companion

The larger and fainter of Andromeda's two bright companions — an elongated dwarf elliptical with an unexpected secret: dark dust lanes and young stars near its centre, rare inside a galaxy of this type.

Distance
~2.7 million light-years
Diameter
~15,000 light-years
Type
Dwarf elliptical (dE6)
Discovered
1783, Caroline Herschel
  • Caroline Herschel found it in 1783, making it one of the first galaxies discovered beyond our own outside the Messier list.
  • Young stars and dust are unusual in dwarf ellipticals; M110's are probably the result of gas pulled in from Andromeda.
  • It is slowly falling towards M31 and may eventually be torn apart and absorbed into its larger neighbour.
  • Its low surface brightness makes it the harder of Andromeda's companions to see — M32 looks far brighter in small telescopes.
NASA — Hubble Messier catalog M110
Spiral · 05
Spiral galaxy

Triangulum Galaxy

M33 · third largest in the Local Group

A small, open-armed spiral seen almost perfectly face-on, which makes its star-forming regions unusually easy to study. It is the third-largest galaxy in our Local Group, after Andromeda and the Milky Way.

Distance
~2.7 million light-years
Diameter
~60,000 light-years
Stars
~40 billion
Orientation
Nearly face-on
  • Its stars are spread so thinly that, despite being bright enough on paper, it is almost invisible to the naked eye — a low surface brightness hides it.
  • The nebula NGC 604 inside it is one of the largest known star-forming regions, around 1,500 light-years across.
  • It may be a distant satellite of Andromeda, and shows signs of a past gravitational encounter with it.
  • Despite holding far fewer stars than its neighbours, it forms new stars at a comparatively brisk rate.
NASA — Hubble Messier catalog M33
Cloud · 06
Irregular (Magellanic spiral) galaxy

Large Magellanic Cloud

LMC · the Milky Way's brightest companion

A bright, uneven galaxy visible as a cloudy patch in the southern sky. It is our closest large companion, a distorted disk of gas and young stars being pulled at by the Milky Way.

Distance
~163,000 light-years
Diameter
~14,000 light-years
Stars
~30 billion
Visible from
Southern hemisphere
  • It contains the Tarantula Nebula, the most active star-forming region in the Local Group — bright enough to be seen from 160,000 light-years away.
  • Supernova 1987A exploded here, the closest supernova observed since the invention of the telescope.
  • A bridge of hydrogen gas links it to the Small Magellanic Cloud, and both trail a long stream of gas stripped by the Milky Way.
  • It has a central bar but no tidy spiral arms, so astronomers classify it as a Magellanic spiral — an irregular galaxy with spiral tendencies.
NASA Science — Galaxies
Cloud · 07
Dwarf irregular galaxy

Small Magellanic Cloud

SMC · a dwarf companion to the Milky Way

A faint, diffuse companion galaxy with no clear structure — no bar, no arms, just gas and stars slowly being shaped by the Milky Way's gravity. It is one of the nearest galaxies to our own.

Distance
~200,000 light-years
Diameter
~7,000 light-years
Stars
Hundreds of millions
Type
Dwarf irregular (dIrr)
  • It holds far less mass than the Large Magellanic Cloud and is being stretched into an elongated shape by their mutual orbit.
  • Both Clouds were long used to calibrate the cosmic distance scale, because their Cepheid variable stars are close enough to resolve.
  • Star formation here is uneven and clumpy, concentrated in bright knots of gas rather than arranged in arms.
  • In a few billion years the Clouds will likely merge with the Milky Way, adding their gas and stars to our own galaxy.
NASA Science — Galaxies

The Local Group

These seven objects are the members of the Local Group you are most likely to see or read about. The Local Group holds more than 80 known galaxies, and nearly all of them are faint dwarf galaxies; only the Milky Way and Andromeda are massive spirals. Everything in this group lies within roughly 10 million light-years of us, a tiny neighbourhood in a universe of hundreds of billions of galaxies.

Distances and figures are rounded averages from standard astronomical catalogues; galaxy sizes vary with how far the faint outer disk is measured.

See these galaxies from your own sky — open the constellation explorer

Sources & credits

Galaxy images are artist's impressions created for ANDROMEDA, not telescope photographs. The Milky Way portrait is a reconstruction; we have no photograph of our own galaxy from outside.

Figures are rounded averages from NASA, ESA and IAU reference data. Star positions on charts are schematic and approximate.

Knowledge check

How well do you know the neighbourhood?

Five questions, instant feedback. Your best score is kept in your progress dashboard.

Question 1 of 50 correct so far

Which galaxy is the largest member of the Local Group?