An Sc galaxy containing 100 billion stars, approximately 30 million light years away. Somewhat smaller than our own galaxy, but otherwise very similar in structure. (Gemini Observatory, GMOS Team, apod030524)

NGC253 is about 10 million light years away, in the Sculptor Group of galaxies, the nearest group to our own Local Group of galaxies. (Jean-Charles Cuillandre (CFHT), Hawaiian Starlight, CFHT, apod030525; Copyright CFHT)

NGC4565, an edge-on spiral galaxy in Coma Berenices, about 30 million light-years from our Milky Way galaxy. Dust scattered throughout the disk obscures its light, but the nuclear bulge is clearly visible above and below the dust lanes. A little over 100,000 light-years in diameter, NGC4565 is thought to be nearly identical to our own galaxy, and as a result, it is presumed that our galaxy would look very much like this, if seen from the same angle. (Bruce Hugo & Leslie Gaul, Adam Block, NOAO/AURA/NSF)

A "thin" spiral galaxy, NGC 5866, is seen exactly edge-on, so that the lanes of gas and dust that fill its disk appear to be nearly a straight line. As remarkable as the galaxy appears, it is likely that many spiral galaxies would appear equally thin if seen from such an angle. The blue disk of young stars extends well past the thin dust lanes, while the central bulge, more orange in color, due to the older, redder stars that exist in the nucleus, extends above and below the disk. About 60 thousand light years in diameter, and 45 million light years away, in the constellation of Draco the Dragon, NGC 5866 is about 30% smaller than our galaxy, but about equally massive, based on its rotational rate. (NASA, ESA, and The Hubble Heritage Team (STScI/AURA), W. Keel (U. Alabama), apod060612)

     Galaxies are always much bigger than they appear in "normally" exposed photographs. Above and below are images of M77, a spiral galaxy in Cetus. The image above (rotated 45 degrees, to correspond to the orientation of the image below; the white lines show the edge of the original image) shows the galaxy as usually photographed, with an unusually bright core (hence its designation as a Seyfert galaxy), and tightly wound spiral arms extending a moderate distance from the core. The image below, which uses a much longer exposure for the outer regions, shows that the actual structure is many times larger.
     Although the density of stars per unit of space is lower in the outer, fainter parts of galaxies, the much larger extent of those regions makes the overall mass of the outer regions comparable to, or even larger than, the mass of the "visible" portions of the galaxy.

One of the closest galaxies, at only 15 million light years distance. (FORS Team, 8.2-meter VLT, ESO, apod030511)

NGC 1365, a barred spiral galaxy in the Fornax Cluster. A rotating density wave helps maintain the structure of the bar and promotes the creation of new stars, which light up the spiral arms extending from the bar. (FORS Team, 8.2-meter VLT Antu, ESO, apod030413)

Bright blue giants light up the outer arms of the strikingly barred spiral galaxy NGC 1300. The 100,000 light-year-diameter galaxy lies a mere 70 million light years away, allowing a detailed examination of its structure, including the remarkable spiral structure near its center. (Hubble Heritage Team, ESA, NASA, apod060827)

About 100,000 light years across, and 150 million light years away. From this direction, dust in the disk obscures the view. (Hubble Heritage Team (STScI / AURA), C. Conselice (U. Wisconsin / STScI) et al., NASA, apod030607)

A relatively small galaxy, at only 30,000 light years across, but only 21 million light years away. Notable because it is a Seyfert galaxy, having an exceptionally bright core. (Bernie and Jay Slotnick, Adam Block, AOP, NOAO, AURA, NSF, apod030417)

Two galaxies, a dusty spiral near the center, and an elliptical at lower left, are colliding. Each galaxy, about 50,000 light years across, is distorted by the gravity of the other one, and as clouds of gas in the galaxies collide, bursts of star formation occur. See M81 and M82: A Cosmic Train Wreck for more about galactic collisions. (Hubble Heritage Team (STScI/AURA), M. Donahue (STScI) & J. Trauger (JPL), NASA, apod030505)

ESO269-57 (the -57 refers to its declination) is a relatively large galaxy, almost 200,000 light years across. Its distance of 150 million light years means that we see it as it was 150 million years ago. (FORS1, VLT, ESO, apod030419)

The bright dot just above the center of the galaxy, NGC 3184, is the supernova. (This is NOT the bright dot near the top of the galaxy, which is a nearby star, in our own galaxy.) NGC 3814 is a type Sbc galaxy about 50,000 light years across, or about half the size of our galaxy. (Al Kelly (JSCAS/NASA) & Arne Henden (Flagstaff/USNO), apod000920)