Since its launch in 1990, the NASA/ESA Hubble Space Telescope has taken thousands of images of astronomical bodies near and far.
Many of its targets have been galaxies or groups of galaxies. A galaxy is a collection of millions or billions of stars—many of which might have planets—plus clouds of gas and dust.
Galaxies come in range of different shapes and sizes. There are spiral galaxies like our Milky Way, plus elliptical galaxies, lenticular galaxies, dwarf galaxies and irregular galaxies.
Prominent galaxies have been given proper names; others are simply known by their catalogue number. One of the better-known catalogues of astronomical objects is the imaginatively named New General Catalogue, or NGC.
Here’s our selection of Hubble’s Top 15 galaxy images.
1. NGC 5866
NGC 5866 is around 50 million light-years away. Sometimes called the Spindle Galaxy, is either a spiral galaxy seen edge on, or a type known as lenticular—halfway between a spiral and an elliptical galaxy. A lane of dark dust clouds is prominent.
2. The Cartwheel Galaxy
This amazing looking galaxy is located 500 million light-years from Earth. Its strange shape is thought to be the result of a collision between two galaxies. It has a nucleus in the centre, a ring of young stars around the outside, and wisps of material connecting the two. It is classed as a ring galaxy.
3. NGC 7049
About 100 million light-years from Earth lies NGC 7049, a large (150 million light-year-wide) half-spiral, half-elliptical galaxy that has dramatic dust clouds ringing its nucleus. This is another example of a structure that might have arisen from a galactic collision.
4. NGC 1512
NGC 1512 is a barred-spiral galaxy about 30 million light-years from Earth. Barred spiral means that it has an elongated section of stars coming out of either side of the nucleus, from which the spiral arms extend and wrap themselves around the galaxy.
5. AM 0644-741
Another ring galaxy, AM 0644-741 is about 300 million light-years from Earth and is a bit wider than our Milky Way galaxy. Again, thought to be the result of a collision between two galaxies, it has nucleus of old stars and a ring of younger stars, whose birth was prompted by the collision.
6. NGC 4921
This is a magnificent image of the face-on spiral galaxy NGC 4921, put together from 80 separate Hubble images. It is 320 million light-years from Earth.
7. NGC 1316
Dark clouds of dust are spread throughout this galaxy, which is just over 60 million light-years from Earth. Classified as a lenticular (half-spiral, half-elliptical) galaxy, it’s yet a further example of a galaxy that is thought to have undergone a merger with another galaxy.
8. Hoag’s Object
This amazing ring galaxy is similar to the Cartwheel and AM 0644-741, but is more perfectly formed. A ring of bright, young stars surrounds its nucleus of older stars. A background galaxy can be seen at about the one o’clock position. Hoag’s Object is about 600 million light-years from Earth.
9. UGC 10214
Nicknamed the “Tadpole”, this remarkable galaxy has been distorted and “stretched” by the gravity of a passing galaxy (the small, blue galaxy in the top-left corner of the Tadpole). It is 420 million light-years from Earth.
10. NGC 4622
A spiral galaxy that spins the wrong way? That’s the conclusion reached by astronomers studying NGC 4622. A normal spiral galaxy has arms that trail around behind as the galaxy slowly spins. But with NGC 4622, the tips of the spiral arms actually point in the direction of rotation. (This has now been established by two different types of observations). This galaxy is 111 million light-years away.
11. NGC 3314
This odd looking galaxy is actually two galaxies, one in front of the other. Together, the two galaxies are known by the catalogue number NGC 3314. The pair are about 140 million light-years from Earth.
12. Sombrero Galaxy
One of the most famous galaxies and a favourite target of recreational astronomers, the Sombrero Galaxy (also known by its catalogue number, M104) is a spiral galaxy seen edge on and encircled by thick dust lanes. M104 has a mass of 800 billion suns, is 50,000 light-years across and is located 28 million light-years from Earth.
13. NGC 7742
This pretty, face-on spiral galaxy hides a dark secret—at its core there probably lives a black hole. (Mind you, the same can probably be said of pretty much all galaxies.) The central part of the galaxy contains lots of older stars. Surrounding that is ring where stars are being born, followed by tightly wrapped spiral arms. On the outside is a dimmer region that was once probably the site of star formation.
14. Stephan’s Quintet
A clash of cosmic proportions is underway in this grouping of galaxies. Although five major galaxies are visible (the galaxy to the right of middle is actually two galaxies interacting), the one in the top left is actually a ring in—known as NGC 7320, it is seven times closer to us than the others, and so is not involved. Three of the others are distorted and disturbed by coming close to each other. NGC 7320 is 40 million light-years from Earth, while the others are around 300 million light-years away.
15. Abell 1689
The huge cluster of galaxies known as Abell 1689 acts as a cosmic lens, distorting our view of other galaxies that lie beyond it. Those other galaxies show up as arcs of light. The gravitational lens effect was predicted by Einstein’s theory of gravity.
NGC 5866: NASA / ESA/ Hubble Heritage Team (STScI / AURA)
The Cartwheel Galaxy: Curt Struck, Philip Appleton (Iowa State University) / Kirk Borne (Hughes STX Corporation) / Ray Lucas (STScI) / NASA / ESA
NGC 7049: NASA / ESA / W. Harris (McMaster University, Canada)
NGC 1512: NASA / ESA / Dan Maoz (Tel-Aviv University, Israel, and Columbia University, USA)
AM 0644-741: NASA / ESA / Hubble Heritage Team (AURA / STScI)
NGC 4921: NASA / ESA / K. Cook (Lawrence Livermore National Laboratory, USA)
NGC 1316: NASA / ESA/ Hubble Heritage Team (STScI / AURA)
Hoag’s Object: NASA / ESA/ Hubble Heritage Team (STScI / AURA)
UGC 10214: NASA / Holland Ford (JHU) / ACS Science Team / ESA
NGC 4622: NASA / ESA/ Hubble Heritage Team (STScI / AURA)
NGC 3314: NASA / ESA/ Hubble Heritage Team (STScI / AURA)
Sombrero Galaxy: NASA / ESA/ Hubble Heritage Team (STScI / AURA)
NGC 7742: NASA / ESA/ Hubble Heritage Team (STScI / AURA)
Stephan’s Quintet: NASA / ESA / Hubble SM4 ERO Team
Abell 1689: NASA / N. Benitez (JHU), T. Broadhurst (The Hebrew University), H. Ford (JHU), M. Clampin (STScI), G. Hartig (STScI), G. Illingworth (UCO/Lick Observatory) / ACS Science Team / ESA.
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