by Jim King
Those of you who are not familiar with Charlie Messier, a short bio follows:
Charles Messier was the tenth of twelve children born to a wealthy French family on June 26, 1730. The loss of his father at the age of eleven changed the family's financial status, however, and Messier left formal education to be schooled at home by his older brother.
At the age of 21, Messier took a position with the Astronomer to the French Navy, where he kept careful records of the observations of the heavens. Messier went on to serve as the chief astronomer of the Marine Observatory in 1759 and later became the Astronomer of the Navy himself in 1771. He became a member of the prestigious Royal Society of London in 1764.
In 1770, at the age of 40, Messier married Marie-Francoise de Vermauchampt. Tragically, his wife died in childbirth less than two years later, along with Messier's new son.
Over the course of his career, Messier discovered and documented forty “nebulae” and 13 comets. He compiled a list of nebulous objects in the Northern Hemisphere known as the Messier Catalog. Messier died on April 12, 1817, at the age of 86.
(An important jargon jogger: Messier uses the descriptive term “nebula” since he was frequently using a 3.5-inch telescope which had difficulty resolving dim stars. It appears that he thought “nebulae” were not gas clouds, but simply unresolved star clouds. Therefore, in our descriptions, we must mentally separate Messier’s “nebulae” from the real thing. He does differentiate nebulosity from luminosity.)
M51 Spiral Galaxy (Observability: Detectible*) M51 is the finest example of a face-on spiral galaxy. It is a highly metallic system with a well-defined spiral structure. A near neighbor of our own Galaxy, just 27 million light-years distant, this graceful pinwheel of stars, dust and gas measures about 87,000 light-years across and shines with a luminosity about 10 billion times that of the Sun’s. According to scientists at the Space Telescope Science Institute, M51’s central area is about 400 million years old and has a mass 40 million times that of our Sun. The concentration of stars is about 5,000 times higher than our solar neighborhood, the Milky Way Galaxy. We would see a continuously bright sky if we lived near the bright center.
Messier note: Observed January 11, 1774. “Very faint nebula without stars, near the more northerly ear of Canes Venatici, below the second-magnitude star in the tail of Ursa Major. Messier discovered this nebula on 13 October 1773, when observing the comet that appeared in that year. It may be seen only with difficulty with a simple three-and-a-half-foot refractor.”
NGC note: “A magnificent object, great nebula.”
Data: Messier 51 aka NGC 5194 aka Whirlpool Galaxy
Con: Canes Venatici Mag: 8.4
RA: 13h30.0m Dec: +47.16
Dist: ~27 million light-years
M62 Globular Cluster (Observability: Easy*) Odd and mystifying are the words that seem to describe M62 in Ophiuchus. A metal-rich globular cluster 22,200 light-years from the Sun, it is singled out in the literature mostly for its strong asymmetry. At 5,500 light-years distant, M62 is the Messier globular closest to the center of the Milky Way Galaxy, so the strong gravitational tug on the globular might account for its peculiar visage. Specifically, the western half of the cluster is dramatically brighter than the eastern half.
Messier note: Observed June 4, 1779. “A very fine nebula, discovered in Scorpius; it resembles a small Comet. The center is bright and is surrounded by faint luminosity”.
NGC note: “Remarkable globular cluster, very bright, large gradually much brighter in the middle, well resolved, stars of 14th to 16th magnitude.”
Data: Messier 62 aka NGC 6266 aka Flickering Globular
Con: Ophiuchus Mag 6.4
RA: 17h01.2 Dec: -30.07
Dist.: ~22,200 ly
M63 Spiral Galaxy (Observability: Detectible) * In images, M63 looks like a spiral galaxy that has lost control of its gravity, and we are catching a rare sight of its arms being tossed into space. This spiral, which is 10 billion times brighter than the Sun, is a prime example of a type of galaxy that displays a lack of cohesion between its inner and outer arms. The inner region of M63’s 100,000 light-year-wide disk (about the size of the Milky Way) is ringed by strong spiral structure, while the plentiful outer arms appear loose, patchy, and haphazard. Not surprisingly, M63 is nicknamed the Sunflower Galaxy because of its resemblance to that towering plant, whose dense, seedy head is ringed by an abundance of bright, overlapping petals.
Messier notes: Observed June 14, 1779. “Nebula discovered by M. Mechain (Messier’s associate) in Canes Venatici. Messier searched for it. It is faint and does not contain any stars. The slightest illumination of the micrometer’s crosshairs causes it to disappear.”
NGC note: “Very bright, large, pretty much extended in about position angle 120 degrees, very suddenly much brighter in the middle to a bright nucleus.”
Data: Messier 63 aka NGC 5055 aka Sunflower Galaxy
Con: Canes Venatici Mag 8.6
RA: 13h15.8m Dec: +42.02
Dist.: ~27 million ly
M85 Lenticular Galaxy (Observability: Difficult) * Although M85 lies in Coma Berenices, it belongs to the Virgo cloud of galaxies. It is a radio-quiet, lenticular galaxy, oriented nearly face-on. In many images, it has an extremely bright, though diffuse, nucleus nested in smooth whorls that form a lens.
One mystery prevails. Many, perhaps most, galaxies, including the Milky Way, harbor a massive black hole at their heart. M85 appears to be an exception.
Messier note: Observed March 18, 1781. “Nebula without a star, above and close to the ear of corn in Virgo, between twos stars in Coma Berenices, Flamsteed 11 and 14. This nebula is very faint.”
NGC note: “Very bright, pretty large, round, with a brighter in the middle, star to the northwest.”
Data: Messier 85 aka NGC 4382
Con: Coma Berenices Mag 9.1
RA: 12h25.4m Dec: +18.11
Dist.: ~56 million ly
***
* Sky Tools software offers an observability scale of 1 – 6, with 1: Obvious; 2: Easy; 3: Apparent; 4: Difficult; 5: Challenging; and 6: Very Challenging. The rating scale I use is based on a Celestron SCT 8 Evolution telescope at the HAS dark site on a moonless night.
Finito!
Ex astris, scientia, y’all!
Jim King
Outreach Chair
Want more? Check out the HAS website under “Programs”/Messier Challenge/HAS 45
