The Big Foto

1 Messier 23 (also known as NGC 6494) is an open cluster in the constellation Sagittarius. It was discovered by Charles Messier on June 20, 1764. M23 is at a distance of about 2,150 light-years away from Earth, its radius is around 15-20 light years. There are some 150 identified members in this cluster, the brightest being of magnitude 9.2. M23 can be found with a modestly sized telescope in the rich starfields of the Sagittarius Milky Way. Credit: N.A.Sharp, REU program/NOAO/AURA/NSF #

2 The Sagittarius Star Cloud (also known as Delle Caustiche, Messier 24, IC 4715) is a star cloud in the constellation of Sagittarius, approximately 600 light years wide, which was discovered by Charles Messier in 1764. The stars, clusters and other objects comprising M24 are part of the Sagittarius or Sagittarius-Carina arms of the Milky Way galaxy. Messier described M24 as a "large nebulosity containing many stars" and gave its dimensions as being some 1.5° across, a description that fits the star cloud rather well. Some sources, improperly, identify M24 as the faint cluster NGC 6603. M24 fills a space of significant volume to a depth of 10,000 to 16,000 light-years. This is the most dense concentration of individual stars visible using binoculars, with around 1,000 stars visible within a single field of view. Credit: Vanessa Harvey, REU program/NOAO/AURA/NSF #

3 Open Cluster M25 (also known as Messier Object 25 or IC 4725) is an open cluster in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745 and included in Charles Messier's list in 1764. M25 is at a distance of about 2,000 light-years away from Earth. The spatial dimension of this cluster is about 19 light years across. A Delta Cephei type variable star designated U Sagittarii is a member of this cluster. Credit: Hillary Mathis, Vanessa Harvey, REU program/NOAO/AURA/NSF #

4 Open Cluster M26 (also known as Messier Object 26 or NGC 6694) is an open cluster in the constellation Scutum. It was discovered by Charles Messier in 1764. M26 spans about 22 light years across and is at a distance of 5,000 light years from the Earth. The brightest star is of magnitude 11.9 and the age of this cluster has been calculated to be 89 million years. An interesting feature of M26 is a region of low star density near the nucleus, most likely caused by an obscuring cloud of interstellar matter between us and the cluster. Credit: George Jacoby, WIYN/NSF #

5 The Dumbbell Nebula (also known as Messier 27, M 27, or NGC 6853) is a planetary nebula (PN) in the constellation Vulpecula, at a distance of about 1360 light years. This object was the first planetary nebula to be discovered; by Charles Messier in 1764. At its brightness of visual magnitude 7.5 and its diameter of about 8 arcminutes, it is easily visible in binoculars, and a popular observing target in amateur telescopes. Credit: George Jacoby, WIYN/NSF #

6 Messier 28 (also known as M28 or NGC 6626) is a globular cluster in the constellation Sagittarius. It was discovered by Charles Messier in 1764. M28 is at a distance of about 18,000 to 19,000 light-years away from Earth. 18 RR Lyrae type variable stars have been observed in this cluster. In 1986, M28 became the first globular cluster where a millisecond pulsar was discovered (by the Lovell Telescope at Jodrell Bank Observatory). Credit: NOAO/AURA/NSF #

7 Messier 29 (also known as M 29 or NGC 6913) is an open cluster in the Cygnus constellation. It was discovered by Charles Messier in 1764, and can be seen from Earth by using binoculars. Credit: NOAO/AURA/NSF #

8 Messier 30 (also known as M30 or NGC 7099) is a globular cluster in the Capricornus constellation. It was discovered by Charles Messier in 1764. M30 is at a distance of about 26,000 light-years away from Earth. Credit: NASA/STScI/WikiSky #

9 The Andromeda Galaxy (also known as Messier 31, M31, or NGC 224; often referred to as the Great Andromeda Nebula in older texts) is a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda. It is the nearest spiral galaxy to our own, the Milky Way. As it is visible as a faint smudge on a moonless night, it is one of the farthest objects visible to the naked eye, and can be seen even from urban areas with binoculars. Credit: T.A.Rector and B.A.Wolpa/NOAO/AURA/NSF #

10 Messier 32 (also known as NGC 221 and Le Gentil) is a dwarf elliptical galaxy about 2.65 million light-years away in the constellation Andromeda. M32 is a satellite galaxy of the famous Andromeda Galaxy (M31) and was discovered by Le Gentil in 1749 and measures only 6.5 ± 0.2 kly in diameter at the widest point. Like most elliptical galaxies, M32 contains mostly older faint red and yellow stars with practically no dust or gas and consequently no current star formation. With this observation, Hubble discovered that the ultraviolet light comes from a population of extremely hot helium-burning stars. Credit: NASA Hubble Space Telescope's - Space Telescope Imageing Spectrograph (STIS) #

11 The Triangulum Galaxy (also known as Messier 33 or NGC 598) is a spiral galaxy approximately 3 million light-years away in the constellation Triangulum. The galaxy is also sometimes informally referred to as the Pinwheel Galaxy by some amateur astronomy references and in some public outreach websites.[7] However, the SIMBAD Astronomical Database, a professional astronomy database that contains formal designations for astronomical objects, indicates that the name "Pinwheel Galaxy" is used to refer to Messier 101. Credit: T.A.Rector (NRAO/AUI/NSF and NOAO/AURA/NSF) and M.Hanna (NOAO/AURA/NSF) or NASA/JPL-Caltech #