Observing the Messier Objects by Kevin Manning
Charles Messier (June 26, 1730 - April 12, 1817) was an astronomer and famous comet hunter in France. Like other scientists, Messier wanted to receive recognition for his work and did so through making new discoveries. While searching the night sky for comets, he found several objects that appeared to be a comet, but upon subsequent evenings of observation, he found that they did not move relative to the stars. Messier concluded that they could not be comets because comets move, and therefore made a list of 110 of these "nuisances." These objects turned out to be some of the brightest star clusters, nebulae and galaxies.
Today, even a modest-sized telescope will reveal all of the Messier Objects on clear dark nights. For some background on the different types of objects this list includes, let's define them here. Open or galactic star clusters are loose collections of tens to hundreds of hot young stars. Globular clusters are roughly spherical regions containing thousands to over a million stars that are particularly old, and are located in the halo region surrounding the core of the Milky Way Galaxy. Nebulae comes from a Greek word meaning "cloud" because it is a cloud of gas and dust in space. Planetary nebulae have roughly spherical boundaries that somewhat resemble a planet, hence their name. A central star literally blew out its outer layer into space forming the nebula. Diffuse nebulae are spread out like a puff of smoke and are regions where new stars and stellar systems are being born. Galaxies are island universes typically containing a 100 billion stars and more along with lots of gas and dust, the raw materials for the formation of new stars and planets.
Messier 1 is known as the Crab Nebula located in the night sky within the boundaries of the constellation (a pattern of stars representing certain figures as seen from earth) Taurus the bull. It is literally the remnant of a stellar explosion known as a supernova that occurred within our galaxy and was observed as a bright star that outshined the full moon in the year 1054 AD. One of the first images recorded by the Chandra X-Ray Observatory was of the area surrounding the stellar corpse in the heart of the nebula. Known as a neutron star, it is a mere 6 miles in diameter and yet weighs about as much as the Sun, creating a density that has "gone through the roof." A teaspoon of this neutron star's material would easily outweigh the empire state building in New York City. This dense stellar corpse is also spinning at a rate of 30 times per second, giving off X-Rays with a similar effect as a lighthouse. That is why we call this object a pulsar.
As we were introduced to some of the different types of objects we find in space and the first Messier Object in the previous article, Observing the Messier Objects (Part 1), this article continues with descriptions of more of the Messier Objects. We will concentrate on those objects that are deemed noteworthy with an attempt to include samples of all the different types. Messier 8 is commonly called the Lagoon Nebula, a diffuse nebula in the constellation Sagittarius. Giving rise to its name, a dark area appears to divide the cloud of glowing gas like a rift, but the dark area is actually dense thick gas and dust that blocks the light behind it, making it look like a gap. This star-rich region lies in the direction toward the plane of and central core of our galaxy, the Milky Way.
Messier (M) 11 is a beautiful rich sample of an open or galactic cluster, commonly called the Wild Duck Cluster. Located in the constellation Scutum, I recall my first telescopic observation of this cluster in 1969 and was impressed with a view rivaling a set of sparkling diamonds on a backdrop of black velvet. M13 is one of the brightest and richest globular clusters located in the constellation Hercules. Globulars appear like a splash of salt or sugar on a table top, with each crystal representing a star. A modest size telescope will easily separate, or resolve, the stars even in the dense core of this cluster. Nearby M13 toward the northeast in the same low power field of view is NGC (New General Catalog) 6207, a distant edge-on galaxy well beyond any star or object in our own Milky Way.
M16 is a star cluster and nebula in the constellation Serpens. This famous object has the common name of the Eagle Nebula due to some dense pillars of gas and dust lying near the heart of this object that resemble a flying eagle. The Hubble Space Telescope (HST) zoomed into this region capturing fantastic details of these pillars we call elephant trunks (for lack of a better term) and clearly showed us that near the top of at least one of them exists new stars in their embryonic stage of development. M17 is the Swan or Omega Nebula in Sagittarius. We often find that objects are called more than one name. Radiation from a local open star cluster causes the gases of the nebula to shine. Let's conclude this installment with M20, the Trifid Nebula. A diffuse nebula also in Sagittarius, its name comes from an appearance resembling 3 sections or lobes. But interestingly besides an open star cluster, the nebula itself is made of 3 kinds. A reflection nebula appears blue, an emission nebula appears red, and dark nebulae gives rise to its name. Many years ago, a former student of mine majoring in art gave me a beautiful painting of this incredibly colorful object.
M27 is a planetary nebula, the first of its kind discovered by Messier, in the constellation Vulpecula. The central star is a white dwarf, the largest ever recorded. As viewed in a telescope with an apparent size larger than 1/4 the Moon's diameter, the nebula appears large and bright. The brightest area has an hourglass shape, and the ear-like appendages round out the shape of the Dumbbell Nebula. M31 is the relatively close and very bright Andromeda Galaxy. It is so bright that the galaxy visually appears as a dim oval patch of light even to the unaided eye. Through a telescope, the view is no less than magnificent. Nearly nine times larger across than the full Moon, this huge island universe reveals many interesting features. Dark clouds highlight shape to the spiral structure, and the star-like core directs you to the bright central region. M32 and M110 are both smaller companion galaxies to the Andromeda, like the Small and Large Magellanic Clouds are to us. Similar to our own, this spiral galaxy 2 million light years away is on a collision course with the Milky Way. No need for concern now, it won't happen until billions of years have gone by.
M33 is another large galaxy in Triangulum. Along with the Milky Way, Andromeda and a few dozen smaller galaxies, the Triangulum Galaxy is part of the Local Group. This face-on spiral has been referred to as the Pinwheel Galaxy, a name most and officially associated with M101, another face-on spiral. M33's low surface brightness makes it a challenge to view in smaller telescopes. M35 is a galactic cluster in Gemini. A loose collection of bright stars almost the size of the full Moon appear in the sky very near a tight older cluster identified as NGC 2158. Messier 42 is a large diffuse cloud known as the Great Orion Nebula. Great being the key word here, this fantastic bright and colorful object lies in the sword or dagger part of Orion the hunter. It is difficult to express in words how truly beautiful this nebula appears in a telescope with its swirling gas and filamentous arms surrounding a star region known as the Trapezium. Part of what is called Barnard's Loop, this stellar nursery lies at a distance of 1,500 light years away. A close-up view with the HST reveals what we theorized to exist a few decades ago, the existence of proplids or protostars, areas where gas and dust coalesced eventually to become new stars and stellar systems.
M44 is an unmistakably bright naked-eye galactic cluster in Cancer the crab known as the Beehive or Praesepe Cluster. Being one of the nearest open clusters, it appears as a large fuzzy patch of light on a clear dark night when Cancer is high in the sky, more than 3 times larger across than the full Moon, and has been known since ancient times. Containing several different types of stars, one can see colors amongst the members of this older cluster.
M45 is an incredible galactic cluster in Taurus known as the Pleiades. Commonly known as the Seven Sisters, this cluster is easily seen as a collection of fairly bright stars that somewhat resemble a little dipper pattern, tricking many into believing it is the Little Dipper. Several stories exist about the cluster arising from the folklore and beliefs of different cultures. For example, native American Indians call it the Seven Dancing Girls. Through a large telescope, surrounding envelopes of nebulosity, though believed to be unrelated to the cluster, can be seen around these very young, hot blue stars.
M46 is a galactic cluster in the constellation Puppis. Near the northern edge of the cluster in the same field of view lies the planetary nebula NGC 2438, though believed to be unrelated.
An absolutely delightful and very famous galaxy is M51, the Whirlpool Galaxy, 23 million light-years away in the constellation Canes Venatici. A companion galaxy (NGC 5195) appears to be connected at the end of one of its spiral arms, adding to the mystique of this celestial wonder. I recall easily seeing the two galaxies and spiral structure in the Whirlpool while at McDonald Observatory, in the Fort Davis mountain area of southwest Texas, using 20 x 80 binoculars. In the sky, M51 is close to the end of the handle of the Big Dipper.
M57 is a planetary nebula in Lyra known as the famous Ring Nebula. Vega is the brightest star in Lyra and marks as one of three making the Summer Triangle. The Ring Nebula appears as a ghostlike smoke ring in space with a faint central star. This is certainly one of the hallmark objects you will want to observe through a telescope.
Three names exist for M76: the Little Dumbbell Nebula, the Barbell Nebula, or the Cork Nebula. It is a bipolar planetary nebula in the constellation Perseus. The name Little Dumbbell Nebula is derived from its resemblance to the Dumbbell Nebula (M27) mentioned in part 3 of this series. It is considered one of the faintest and hardest to see objects in Messier's list. M78 is very bright diffuse nebula known more specifically as a reflection nebula due to its reflecting the light of a pair of relatively bright stars. Located in the constellation Orion, it appears as a hazy fan-shaped display through a modest telescope. M81 is commonly referred to as Bode's Galaxy in the Big Bear constellation Ursa Major, the biggest part thereof being the Big Dipper. This large bright galaxy is believed to have a very active nucleus harboring an extremely supermassive black hole. Two other galaxies interact gravitationally with M81, including the nearby M82, commonly called the Cigar Galaxy because of its shape. Both galaxies can be seen in the same low power field of view in a modest sized telescope. M82 was previously thought to be an irregular galaxy (the 4 main classes of galaxies include spiral, elliptical, irregular, and lenticular). Gravitational tidal forces from nearby M81 has caused the rate of star formation in the core of M82 to increase tenfold compared to normal galaxies, earning it the name starburst galaxy.
M83 is one of the closest and brightest barred spiral galaxies in the night sky, making it easily visible with binoculars. Commonly called the Southern Pinwheel Galaxy, M83 is located in the constellation Hydra. It is personally one of my favorite galaxies to study due to its beauty and highly energetic status in the birth and death of stars. M97 is a complex planetary nebula known as the Owl Nebula near the Big Dipper in Ursa Major. The name is a result of the appearance of owl-like "eyes" when viewed through a telescope (hooooo). Also in Ursa Major is M101, the Pinwheel Galaxy that looks like a pinwheel as a face-on spiral of stars, gas and dust. M101 is nearly twice the size of our galaxy and contains many areas of high star formation known as HII regions. A relatively recent near collision with another galaxy is believed to have caused the asymmetry seen on one side of M101. Our last M-object to consider in this series is Messier 104, the Sombrero Galaxy. It is an edge-wise view of a spiral galaxy in the constellation Virgo that resembles a sombrero hat due to its unusually large central bulge and prominent dark dust lane. One possible explanation for the bulge is a large number of globular clusters observed within this galaxy. The dust lane forms an outer ring to this bulge and is an area of much star formation within the cold dark dust.
This concludes our journey into the cosmos looking into some of the most famous and brightest objects available to be seen n the night sky.
Charles Messier (June 26, 1730 - April 12, 1817) was an astronomer and famous comet hunter in France. Like other scientists, Messier wanted to receive recognition for his work and did so through making new discoveries. While searching the night sky for comets, he found several objects that appeared to be a comet, but upon subsequent evenings of observation, he found that they did not move relative to the stars. Messier concluded that they could not be comets because comets move, and therefore made a list of 110 of these "nuisances." These objects turned out to be some of the brightest star clusters, nebulae and galaxies.
Today, even a modest-sized telescope will reveal all of the Messier Objects on clear dark nights. For some background on the different types of objects this list includes, let's define them here. Open or galactic star clusters are loose collections of tens to hundreds of hot young stars. Globular clusters are roughly spherical regions containing thousands to over a million stars that are particularly old, and are located in the halo region surrounding the core of the Milky Way Galaxy. Nebulae comes from a Greek word meaning "cloud" because it is a cloud of gas and dust in space. Planetary nebulae have roughly spherical boundaries that somewhat resemble a planet, hence their name. A central star literally blew out its outer layer into space forming the nebula. Diffuse nebulae are spread out like a puff of smoke and are regions where new stars and stellar systems are being born. Galaxies are island universes typically containing a 100 billion stars and more along with lots of gas and dust, the raw materials for the formation of new stars and planets.
Messier 1 is known as the Crab Nebula located in the night sky within the boundaries of the constellation (a pattern of stars representing certain figures as seen from earth) Taurus the bull. It is literally the remnant of a stellar explosion known as a supernova that occurred within our galaxy and was observed as a bright star that outshined the full moon in the year 1054 AD. One of the first images recorded by the Chandra X-Ray Observatory was of the area surrounding the stellar corpse in the heart of the nebula. Known as a neutron star, it is a mere 6 miles in diameter and yet weighs about as much as the Sun, creating a density that has "gone through the roof." A teaspoon of this neutron star's material would easily outweigh the empire state building in New York City. This dense stellar corpse is also spinning at a rate of 30 times per second, giving off X-Rays with a similar effect as a lighthouse. That is why we call this object a pulsar.
As we were introduced to some of the different types of objects we find in space and the first Messier Object in the previous article, Observing the Messier Objects (Part 1), this article continues with descriptions of more of the Messier Objects. We will concentrate on those objects that are deemed noteworthy with an attempt to include samples of all the different types. Messier 8 is commonly called the Lagoon Nebula, a diffuse nebula in the constellation Sagittarius. Giving rise to its name, a dark area appears to divide the cloud of glowing gas like a rift, but the dark area is actually dense thick gas and dust that blocks the light behind it, making it look like a gap. This star-rich region lies in the direction toward the plane of and central core of our galaxy, the Milky Way.
Messier (M) 11 is a beautiful rich sample of an open or galactic cluster, commonly called the Wild Duck Cluster. Located in the constellation Scutum, I recall my first telescopic observation of this cluster in 1969 and was impressed with a view rivaling a set of sparkling diamonds on a backdrop of black velvet. M13 is one of the brightest and richest globular clusters located in the constellation Hercules. Globulars appear like a splash of salt or sugar on a table top, with each crystal representing a star. A modest size telescope will easily separate, or resolve, the stars even in the dense core of this cluster. Nearby M13 toward the northeast in the same low power field of view is NGC (New General Catalog) 6207, a distant edge-on galaxy well beyond any star or object in our own Milky Way.
M16 is a star cluster and nebula in the constellation Serpens. This famous object has the common name of the Eagle Nebula due to some dense pillars of gas and dust lying near the heart of this object that resemble a flying eagle. The Hubble Space Telescope (HST) zoomed into this region capturing fantastic details of these pillars we call elephant trunks (for lack of a better term) and clearly showed us that near the top of at least one of them exists new stars in their embryonic stage of development. M17 is the Swan or Omega Nebula in Sagittarius. We often find that objects are called more than one name. Radiation from a local open star cluster causes the gases of the nebula to shine. Let's conclude this installment with M20, the Trifid Nebula. A diffuse nebula also in Sagittarius, its name comes from an appearance resembling 3 sections or lobes. But interestingly besides an open star cluster, the nebula itself is made of 3 kinds. A reflection nebula appears blue, an emission nebula appears red, and dark nebulae gives rise to its name. Many years ago, a former student of mine majoring in art gave me a beautiful painting of this incredibly colorful object.
M27 is a planetary nebula, the first of its kind discovered by Messier, in the constellation Vulpecula. The central star is a white dwarf, the largest ever recorded. As viewed in a telescope with an apparent size larger than 1/4 the Moon's diameter, the nebula appears large and bright. The brightest area has an hourglass shape, and the ear-like appendages round out the shape of the Dumbbell Nebula. M31 is the relatively close and very bright Andromeda Galaxy. It is so bright that the galaxy visually appears as a dim oval patch of light even to the unaided eye. Through a telescope, the view is no less than magnificent. Nearly nine times larger across than the full Moon, this huge island universe reveals many interesting features. Dark clouds highlight shape to the spiral structure, and the star-like core directs you to the bright central region. M32 and M110 are both smaller companion galaxies to the Andromeda, like the Small and Large Magellanic Clouds are to us. Similar to our own, this spiral galaxy 2 million light years away is on a collision course with the Milky Way. No need for concern now, it won't happen until billions of years have gone by.
M33 is another large galaxy in Triangulum. Along with the Milky Way, Andromeda and a few dozen smaller galaxies, the Triangulum Galaxy is part of the Local Group. This face-on spiral has been referred to as the Pinwheel Galaxy, a name most and officially associated with M101, another face-on spiral. M33's low surface brightness makes it a challenge to view in smaller telescopes. M35 is a galactic cluster in Gemini. A loose collection of bright stars almost the size of the full Moon appear in the sky very near a tight older cluster identified as NGC 2158. Messier 42 is a large diffuse cloud known as the Great Orion Nebula. Great being the key word here, this fantastic bright and colorful object lies in the sword or dagger part of Orion the hunter. It is difficult to express in words how truly beautiful this nebula appears in a telescope with its swirling gas and filamentous arms surrounding a star region known as the Trapezium. Part of what is called Barnard's Loop, this stellar nursery lies at a distance of 1,500 light years away. A close-up view with the HST reveals what we theorized to exist a few decades ago, the existence of proplids or protostars, areas where gas and dust coalesced eventually to become new stars and stellar systems.
M44 is an unmistakably bright naked-eye galactic cluster in Cancer the crab known as the Beehive or Praesepe Cluster. Being one of the nearest open clusters, it appears as a large fuzzy patch of light on a clear dark night when Cancer is high in the sky, more than 3 times larger across than the full Moon, and has been known since ancient times. Containing several different types of stars, one can see colors amongst the members of this older cluster.
M45 is an incredible galactic cluster in Taurus known as the Pleiades. Commonly known as the Seven Sisters, this cluster is easily seen as a collection of fairly bright stars that somewhat resemble a little dipper pattern, tricking many into believing it is the Little Dipper. Several stories exist about the cluster arising from the folklore and beliefs of different cultures. For example, native American Indians call it the Seven Dancing Girls. Through a large telescope, surrounding envelopes of nebulosity, though believed to be unrelated to the cluster, can be seen around these very young, hot blue stars.
M46 is a galactic cluster in the constellation Puppis. Near the northern edge of the cluster in the same field of view lies the planetary nebula NGC 2438, though believed to be unrelated.
An absolutely delightful and very famous galaxy is M51, the Whirlpool Galaxy, 23 million light-years away in the constellation Canes Venatici. A companion galaxy (NGC 5195) appears to be connected at the end of one of its spiral arms, adding to the mystique of this celestial wonder. I recall easily seeing the two galaxies and spiral structure in the Whirlpool while at McDonald Observatory, in the Fort Davis mountain area of southwest Texas, using 20 x 80 binoculars. In the sky, M51 is close to the end of the handle of the Big Dipper.
M57 is a planetary nebula in Lyra known as the famous Ring Nebula. Vega is the brightest star in Lyra and marks as one of three making the Summer Triangle. The Ring Nebula appears as a ghostlike smoke ring in space with a faint central star. This is certainly one of the hallmark objects you will want to observe through a telescope.
Three names exist for M76: the Little Dumbbell Nebula, the Barbell Nebula, or the Cork Nebula. It is a bipolar planetary nebula in the constellation Perseus. The name Little Dumbbell Nebula is derived from its resemblance to the Dumbbell Nebula (M27) mentioned in part 3 of this series. It is considered one of the faintest and hardest to see objects in Messier's list. M78 is very bright diffuse nebula known more specifically as a reflection nebula due to its reflecting the light of a pair of relatively bright stars. Located in the constellation Orion, it appears as a hazy fan-shaped display through a modest telescope. M81 is commonly referred to as Bode's Galaxy in the Big Bear constellation Ursa Major, the biggest part thereof being the Big Dipper. This large bright galaxy is believed to have a very active nucleus harboring an extremely supermassive black hole. Two other galaxies interact gravitationally with M81, including the nearby M82, commonly called the Cigar Galaxy because of its shape. Both galaxies can be seen in the same low power field of view in a modest sized telescope. M82 was previously thought to be an irregular galaxy (the 4 main classes of galaxies include spiral, elliptical, irregular, and lenticular). Gravitational tidal forces from nearby M81 has caused the rate of star formation in the core of M82 to increase tenfold compared to normal galaxies, earning it the name starburst galaxy.
M83 is one of the closest and brightest barred spiral galaxies in the night sky, making it easily visible with binoculars. Commonly called the Southern Pinwheel Galaxy, M83 is located in the constellation Hydra. It is personally one of my favorite galaxies to study due to its beauty and highly energetic status in the birth and death of stars. M97 is a complex planetary nebula known as the Owl Nebula near the Big Dipper in Ursa Major. The name is a result of the appearance of owl-like "eyes" when viewed through a telescope (hooooo). Also in Ursa Major is M101, the Pinwheel Galaxy that looks like a pinwheel as a face-on spiral of stars, gas and dust. M101 is nearly twice the size of our galaxy and contains many areas of high star formation known as HII regions. A relatively recent near collision with another galaxy is believed to have caused the asymmetry seen on one side of M101. Our last M-object to consider in this series is Messier 104, the Sombrero Galaxy. It is an edge-wise view of a spiral galaxy in the constellation Virgo that resembles a sombrero hat due to its unusually large central bulge and prominent dark dust lane. One possible explanation for the bulge is a large number of globular clusters observed within this galaxy. The dust lane forms an outer ring to this bulge and is an area of much star formation within the cold dark dust.
This concludes our journey into the cosmos looking into some of the most famous and brightest objects available to be seen n the night sky.