Stars are not randomly sprinkled throughout the universe. They are grouped in galaxies, each of which contain billions of stars. Our Solar system forms a tiny part of a galaxy called the Milky Way.
Here is a list (with examples) of some of the objects found in our universe:
Galaxies
The Andromeda Galaxy
M31 is the famous Andromeda galaxy, our nearest large neighbor galaxy, forming the Local Group of galaxies together with its companions (including M32 and M110, two bright dwarf elliptical galaxies), our Milky Way and its companions, M33, and others. Visible to the naked eye even under moderate conditions, this object was known as the "little cloud" to the Persian astronomer Al-Sufi, who observed it as early as 905 AD (described 964 AD in his Book of Fixed Stars).
Star Clusters
The Pleiades
The Pleiades are among those objects which are known since the earliest times. At least 6 member stars are visible to the naked eye, while under moderate conditions this number increases to 9, and under clear dark skies jumps up to more than a dozen
Nebulae
The Dumbbell Nebula
The Dumbbell Nebula M27 was the first planetary nebula ever discovered. On July 12, 1764, Charles Messier discovered this new and fascinating class of objects. We happen to see this one approximately from its equatorial plane (approx. left-to-right in our image); from near one pole, it would probably have the shape of a ring, and perhaps look like we view the Ring Nebula M57.
Hubble Finds Mysterious Ring Structure Around...
Supernova 1987A
Target Name: Supernova 1987A
Spacecraft: Hubble Space Telescope
Produced by: Dr. Christopher Burrows, ESA/STScI, and NASA
Copyright: Public Domain
Cross Reference: STScI-PR94-22
Date Released: 19 May 1994
This striking NASA Hubble Space Telescope picture shows three rings of glowing gas encircling the site of supernova 1987A, a star which exploded in February 1987.
Though all of the rings appear inclined to our view (so that they appear to intersect) they are probably in three different planes. The small bright ring lies in a plane containing the supernova, the two larger rings lie in front and behind it.
The rings are a surprise because astronomers expected to see, instead, an hourglass shaped bubble of gas being blown into space by the supernova's progenitor star (based on previous HST observations, and images at lower resolution taken at ground-based observatories).
One possibility is that the two rings might be "painted" on the invisible hourglass by a high-energy beam of radiation that is sweeping across the gas, like a searchlight sweeping across clouds. The source of the radiation might be a previously unknown stellar remnant that is a binary companion to the star that exploded in 1987.
The supernova is 169,000 light years away, and lies in the dwarf galaxy called the Large Magellanic Cloud, which can be seen from the southern hemisphere.
The image was taken in visible light (hyrdrogen-alpha emission), with the Wide Field Planetary Camera 2, in February 1994.
Image use statement at the time this image was obtained.
All of the HST images available via WWW and ftp may be used without restriction as long as credit information accompanies the picture. Credit usually includes the principal scientist responsible for the data, AURA/STScI, NASA and/or ESA, the European Space Agency. Specific credit information may be found in the captions accompanying the images as plain text files. The captions are available via links from the Web pages as well as separate files in the gif directory on the ftp server.
