El messier catalog is a compilation of celestial objects, created by the French astronomer Charles Messier in the XNUMXth century. Charles Messier, passionate about astronomy, wanted to avoid confusion between comets and other diffuse objects in the sky that could be confused with them. For this reason, he decided to compile a list of celestial objects other than comets, with the aim of helping astronomers and hobbyists to more accurately identify these objects.
In this article we are going to explain what are the characteristics and importance of the Messier catalog and what are the main celestial objects.
Key features
The Messier catalog consists of 110 objects, ranging from nebulae and star clusters to galaxies. To select these objects, Messier relied on his own observations and the work of other astronomers at the time. Each object in the catalog is assigned a Roman numeral from I to C (1 to 100), with some additional objects designated by the letters A and B. For example, lhe famous Andromeda galaxy is known as M31 in the Messier catalogue.
The creation of this catalog revolutionized the way astronomers classified and cataloged celestial objects. Until then, most diffuse objects were considered comets until proven otherwise. The Messier catalog allowed a better organization and classification of these objects, as well as their more detailed study.
Today, the Messier catalog remains an invaluable tool for astronomers and astronomy enthusiasts. Many of the objects included in the catalog are visible even with modest telescopes, making them popular targets for amateur observers. Besides, this catalog has served as a basis for the discovery and study of other celestial objects beyond those originally listed.
Messier Catalog History
The history of the Messier catalog is closely related to comets. Messier invested time and effort in locating these objects. But let's put ourselves in context. Today we know that there are billions of comets in the outermost regions of the solar system. However, since 1995, only about 900 comets had been discovered. This is because most are too faint to be detected at a distance. But sometimes these comets come close to the inner regions of the solar system and become bright enough to be seen.
It was in 1744 that this happened to the comet Klinkenberg-Shesso, which grew brighter as it got closer to the Sun. Within a few months, the comet reached magnitude -7, making it the brightest object in the sky. , second only to the Moon and the Sun. This striking comet has attracted the attention of professional and amateur astronomers, including the young Charles Messier.
This fascination led Messier to dedicate his life and work to astronomy. Years later, in 1758, Messier dove into the search for comets and discovered a diffuse object in the constellation Taurus. After careful observation, he realized that the object could not be a comet because it was not moving across the sky. Known today as M1 or the Crab Nebula, this object was the first object in Messier's catalog of nebulae and star clusters.
Messier has since taken notice and began cataloging other potentially misleading comet-like objects to prevent other astronomers from mistaking the object for a comet.
Messier catalog as seen by Hubble
The messiest objects are often the brightest and most dramatic. But seen through the Hubble Space Telescope, they are even more spectacular.. NASA recently posted on its website a list of all the Messier objects photographed by Hubble.
Although Hubble has not photographed all the objects, it has succeeded in photographing most of them. We have recorded 96 of these wonderful photos so far. Some of these images are not whole objects, but instead focus on specific areas. That's because Hubble has a relatively small field of view. Therefore, in some cases, it is necessary to take many images to capture the entire object, which is not always efficient. NASA was allowed to do multiple exposures only when the scientific merit justified the time spent. Take the Andromeda galaxy, for example. About 7400 images are required to obtain a mosaic of a small portion of this massive galaxy.
Importance among amateur astronomers
The 110 objects in Messier's catalog are the most popular among amateur astronomers. There is no fan who hasn't taken the time to watch them as much as possible. Therefore, these objects always receive special attention during any observation activity.
But there is one night in particular when these objects take center stage. This is the Messier Marathon, held every year on the new moon closest to the spring or fall equinox. That night, an attempt is made to locate and observe all 110 objects. Without a doubt, this is a beautiful and special challenge for any astronomy fan.
Most important celestial objects in the Messier catalog
Of the 110 objects that belong to this catalogue, these are the 5 best known:
- M31, the Andromeda Galaxy: It is the closest spiral galaxy to the Milky Way and is visible to the naked eye under dark sky conditions. Its spiral shape and size are impressive, and it is estimated that it contains more than a billion stars.
- M42, the Orion Nebula: Located in the constellation Orion, this nebula is one of the best known and most photographed in the sky. It is a region of active star formation, where new stars are born surrounded by clouds of gas and dust.
- M13, the Hercules Globular Cluster: This globular cluster is one of the most impressive of its kind. It is made up of hundreds of thousands of stars that are grouped together in a dense and compact sphere.
- M51, the Whirlpool Galaxy: This barred spiral galaxy is famous for its distinctive swirl-shaped structure. Additionally, M51 is known for its gravitational interaction with a smaller neighboring galaxy, which has created spectacular tidal arms.
- M45, the Pleiades: Also known as the Seven Sisters, the Pleiades is an open star cluster that stands out for its beauty in the night sky. The Pleiades are a popular target for both viewing with the naked eye and through telescopes.
I hope that with this information you can learn more about the Messier catalog and its importance.