Messier 39

the messier 39

Located in the constellation Cygnus, between Deneb and the Cocoon Nebula (IC 5146), lies a rather nondescript but intriguing open star cluster. From our point of view on Earth, this celestial object is known as Messier 39. However, it is also listed in the NGC catalog as NGC 7092, classified as Mel 236 in the De Melotte catalog and identified as Cr 438 in the catalog. by Collinder.

In this article we are going to tell you all the characteristics and importance about the Messier 39 and the entire catalog.

Messier 39

stars in the sky

This particular star cluster, located approximately 800 light years away, stands out as one of the closest open clusters within our reach. Composed of approximately 30 stars, there are a handful, approximately 10, that shine brighter with magnitudes ranging between 6 and 9. Additionally, this cluster covers a considerable area in the sky, comparable to the size of a full Moon. With an apparent magnitude of 4,6 and a surface brightness of 11,8 mag/min arc2, it radiates significant luminosity.

This open cluster was captured in a photograph on December 8, 2018, using a Skywatcher 200/1000 reflecting telescope and a Canon EOS 550D camera, as seen from Querol. With a magnitude barely detectable with the naked eye, this celestial object is at the threshold of human perception. However, when viewed through binoculars, its presence becomes unmistakable. Due to its large extension, it is recommended to observe it with binoculars or a low magnification telescope. Some claim to have glimpsed it without any help, but only under the condition of a pitch-black sky and without artificial lighting, and even then it appears as a blur.

Who discovered it?

messier 39

Comet hunter Charles Messier is credited as the official discoverer of this celestial object in 1764. However, some maintain that French astronomer Guillaume Le Gentil actually detected it in 1750. There are even claims that Aristotle observed it as early as the XNUMXth century. IV BC, which seems plausible considering the absence of light pollution during his time. Under optimal conditions, it is possible to observe this phenomenon with the naked eye.

Like most open clusters, M39 consists of a collection of young stars that originated from a single nebula and emerged simultaneously. More precisely, the stars within M39 are about 300 million years old, indicating their relative youth (for comparison, our Sun has a lifespan of about 5 billion years).

What is the Messier catalog?

star cluster

The Messier Catalog is a compilation of astronomical objects that have been meticulously documented. In 1774, French astronomer Charles Messier compiled a comprehensive list of 110 astronomical objects known as the Messier Catalog.

Messier's main focus was locating comets, but he encountered a challenge in trying to differentiate between diffuse objects in the sky and real comets using the telescopes available at his time. To address this question, Messier took it upon himself to compile a list that would help not only him but also other comet hunters easily distinguish known objects from potential comets. This way, They would not mistake these hazy formations in the sky for new comets.

Messier's catalog is a compilation of various celestial objects, including nebulae, open and globular star clusters, and galaxies, reflecting their varied nature. Messier meticulously examined observations made by previous astronomers, ensuring their accuracy. Furthermore, he incorporated the findings of his fellow astronomer Pierre Meschen, who contributed to the identification of almost half of the objects listed in Messier's catalogue. The initial addition to this collection was the notable spiral galaxy known as M63. Messier diligently confirmed the information provided by Meschen and integrated it into his extensive catalogue.

Evolution of the Messier catalog

In 1774, the initial publication of Messier's catalog included a total of 45 objects. Fast forward to 1781, when the final edition was published, expanding the catalog to include a total of 103 objects.

Messier initially intended to conclude his catalog with an impressive 100 celestial objects. However, just before the final manuscript was ready for publication, Meshen revealed the existence of three additional entities. Unfortunately, Messier's work on the catalog was abruptly stopped due to a serious injury. Furthermore, the English astronomer William Herschel, equipped with more advanced instruments, surpassed Messier's achievement by compiling a catalog that included a staggering 2.500 objects.

After Messier's death, its catalog was expanded to include M110, since he had observed certain objects but had not designated them with individual numbers. Meshen took over M104 – M107. Furthermore, reference had already been made to M108 and M109 in the description of M97.

Messier, although he observed M110, the satellite of the Andromeda Nebula, did not consider it essential to designate it with a specific numerical designation.

The compilation known as Messier's Catalog exerts great fascination among those who practice astronomy as a hobby. What makes it particularly intriguing is the fact that it was assembled in the late 18th century, a time when telescopes lacked the impressive capabilities they possess today. That's why, Only the brightest celestial objects appear in Messier's catalog, which are also the easiest to observe with an amateur telescope. However, there are notable entities that didn't make the cut in Messier's catalog. For example, the Chi and Ash Perseus star clusters (NGC 884 and NGC 869) or the Leo galaxy NGC 3628, which is as notable as its neighboring counterparts M65 and M66.

For amateur astronomers, the NGC offers a more extensive catalog of galaxies and nebulae, although observing most of them requires the use of more advanced equipment than a typical telescope. As objects are discovered and recorded in the catalogue, they are assigned sequential numbers and identified by the letter 'M' preceding the number.

I hope that with this information you can learn more about the Messier 39 and its characteristics.

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