M82 which is also known as the Cigar Galazy is a starburst galaxy about 12M LY away in the constellation Ursa Major. It is about 5 times more luminous than the whole Milky Way and its explosive looking starburst activity is thought to be triggered by interaction with neighboring galaxy M81.
NGC 891 spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30 million light-years distant in the constellation Andromeda, NGC 891 looks a lot like our Milky Way. At first glance, it has a flat, thin, galactic disk and a central bulge cut along the middle by regions of dark obscuring dust. The combined image data also reveal the galaxy’s young blue star clusters and telltale pinkish star forming regions. And remarkably apparent in NGC 891’s edge-on presentation are filaments of dust that extend hundreds of light-years above and below the center line. The dust has likely been blown out of the disk by supernova explosions or intense star formation activity. Faint neighboring galaxies can also be seen near this galaxy’s disk.
Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier’s famous 18th century catalog. The background galaxies are about one tenth the apparent size of NGC 7331 and so lie roughly ten times farther away. Their close alignment on the sky with NGC 7331 occurs just by chance.
The Triangulum Galaxy is a spiral galaxy approximately 3 million light years from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598, and is sometimes informally referred to as the Pinwheel Galaxy, a nickname it shares with Messier 101. The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, which includes the Milky Way Galaxy, the Andromeda Galaxy and about 30 other smaller galaxies. It is one of the most distant permanent objects that can be viewed with the naked eye.
NGC 4567 and NGC 4568 (nicknamed the Siamese Twins or the Butterfly Galaxies) are a set of spiral galaxies about 60 million light-years away in the constellation Virgo. They were both discovered by William Herschel in 1784 and are part of the Virgo cluster of galaxies. These galaxies may be in the process of colliding and merging with each other. They were named “Siamese Twins” because they look like they’re connected.
The Sunflower Galaxy (also known as Messier 63, M63, or NGC 5055) is a spiral galaxy in the constellation Canes Venatici consisting of a central disc surrounded by many short spiral arm segments. The Sunflower Galaxy is part of the M51 Group, a group of galaxies that also includes the Whirlpool Galaxy (M51).
The Whirlpool Galaxy (also known as Messier 51a, M51a, or NGC 5194) is an interacting grand-design spiral galaxy located at a distance of approximately 31 million light-years from the Milky Way Galaxy in the constellation Canes Venatici. It is one of the most famous galaxies in the sky. The galaxy and its companion (NGC 5195) are easily observed by amateur astronomers, and the two galaxies may even be seen with binoculars. The Whirlpool Galaxy is also a popular target for professional astronomers, who study it to further understand galaxy structure (particularly structure associated with the spiral arms) and galaxy interactions.
The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda. It is also known as Messier 31, M31, or NGC 224, and is often referred to as the Great Andromeda Nebula in older texts. Andromeda is the nearest spiral galaxy to the Milky Way, but not the closest galaxy overall. Andromeda is the largest galaxy of the Local Group, which consists of the Andromeda Galaxy, the Milky Way Galaxy, the Triangulum Galaxy, and about 30 other smaller galaxies.
M81 (top) and M82 (bottom). M82 is one of two galaxies that is strongly gravitationally interacting with M81. This galaxy group, consisting of M81, M82, NGC 3077 and NGC 2976, is the nearest galaxy group to our own local group of galaxies. Our local group contains the Milky Way, Magellanic Clouds, M33, and the M31 – M32 – M110 system. At 12 million light years distance, the nearby proximity of galaxies M81 and M82 makes them one of the most spectacular sights in the spring sky.
M101 is a relatively large galaxy compared to the Milky Way. With a diameter of 170,000 light-years it is nearly twice the size of the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small bulge of about 3 billion solar masses. Another remarkable property of this galaxy is its huge and extremely bright H II regions, of which a total of about 3,000 can be seen on photographs. H II regions usually accompany the enormous clouds of high density molecular hydrogen gas contracting under their own gravitational force where stars form. H II regions are ionized by large numbers of extremely bright and hot young stars.
Markarian’s Chain is a stretch of galaxies that forms part of the Virgo Cluster. It’s called a “chain” because, when viewed from Earth, the galaxies lie along a smoothly curved line. It was named after the Armenian astrophysicist, B. E. Markarian, who discovered their common proper motion in the mid 1970s. Member galaxies include M84 (NGC 4374), M86 (NGC 4406), NGC 4477, NGC 4473, NGC 4461, NGC 4458, NGC 4438 and NGC 4435
This is a rich field of galaxies in the constellation of Pegasus. The two major groupings are the Deer Lick Group, in the upper-left, and Stephan’s Quintet in the lower-right. NGC 7331 is the largest and most obvious galaxy in this picture, and is the “showcase piece” in the Deer Lick Group
NGC 4565 (also known as the Needle Galaxy or Caldwell 38) is an edge-on unbarred spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. It is known as the Needle Galaxy for its narrow profile. First spotted in 1785 by Sir William Herschel (1738-1822), this is one of the most famous examples of an edge-on spiral galaxy.
The Leo Triplet (also known as the M66 Group) is a small group of galaxies about 35 million light-years away in the constellation Leo. This galaxy group consists of the spiral galaxies M65, the M66, and the NGC 3628.