Personal Page Amateur Astronomer
«« Messier catalog
A list compiled by French astronomer Charles Messier, which includes 110 celestial objects, and first published in 1774. Messier called comet hunter and one day, he set a goal to create a catalog of fixed nebulae and star clusters, which can be confused with comets. For this reason, in the catalog were different cosmic objects: galaxies, globular clusters, emission nebulae, open clusters, planetary nebula. While the true nature of these objects was not known, and Messier described it simply as a nebula or star clusters.
The first edition included objects M1 - M45. The catalog itself in its final form was established in 1781 and published in 1784, later it was supplemented by objects that were observed by Messier, but for one reason or another were not included in the latest edition of the catalog. For many of these objects is assigned to Messier's number is still the main title.
Because Messier lived in France, which is located in the northern hemisphere, the catalog contains only objects north of 35 ° south latitude. Such large-scale education, such as the Magellanic Clouds, have remained outside the list.
Create a directory
In August 1758, observing comet C/1758 K1, open De La Nude, Messier discovered a nebula, which at first took for a comet. However, after the registration of the lack of its own motion, it became clear that an open object comet is not.
Later, in 1801, Messier recalled:
"I am compelled to create this directory Nebula in Taurus, which I found September 12, 1758, observing the comet of the year. The shape and brightness of the nebula were so similar to the comet, which I have set myself the task of finding others like it, so astronomers can not confuse them with comets. I continued to observe with telescopes available for the opening of the comets, which had occupied my mind when I made this directory. "
Messier discovered September 12, 1758 object, which he included in the list at No. 1, marked the beginning of a catalog. Messier was not the discoverer of the object representing the remnants of a supernova which exploded, according to accounts of Arab and Chinese astronomers, July 4, 1054: his first watch in 1731 by John Bevis.
The next object, M2, was introduced in the catalog until two years later, September 11, 1760. Messier also was a pioneer of this object: before, September 11, 1746, he was already observed by Jean Dominique Maraldi.
M3 - M40
Since May 1764 Messier engaged in a systematic search of new objects, like comets. He began by pointing to the works of other astronomers (in particular, Hevelius, Huygens, Derhama, Halley, de Shezo, Lakaylya and treatment Zhentilya) by writing out information about how they found obscure objects. Next, Messier took up checking of these observations, the measurement of the provisions of the old and the search for such new facilities - and did it very quickly: the catalog increased from 2 to 40 sites for just six months, it will contain 19 units, which were described by Messier for the first time.
M41 - M45
In early 1765 he brought Messier object in its list of M41 - open cluster of stars in the constellation Canis Major. This was followed by a long break in the observations - Messier traveled along the coast of the Netherlands, opened a new comet, but do not add new sites to its list - probably thinking about the prospects of its publication. In March 1769 Messier cataloged four well-known to astronomers the object (the Orion Nebula - M42, M43, Praesepe cluster - M44 and M45 or the Pleiades) - probably to his catalog was more than a directory, compiled Lakaylem, as these objects were not at all like a comet.
The manuscript of the first edition of the catalog was completed February 16, 1771 and printed in the same year. It is interesting to note that Messier in his preface to this edition is already set himself a different, more ambitious goal: to describe all the nebulae visible in the telescope, not just those that are similar to those of comets. Despite this, Messier did not include in the catalog, some long-known nebulous objects that can not be confused with comets (eg, double cluster h and χ Persei) - especially as dial "round" number in the 50 objects in this way was still not .
M46 - M52
February 19, 1771, three days after the manuscript of the first edition of the catalog, Messier discovered another 4 objects. The objects M46, M47 and M48 were the open clusters, and the fourth object, M49, had a different nature: it was later discovered that this galaxy to the Virgo cluster otnosyaschasya.
June 6, 1771 Messier discovered another object whose position in the sky was measured much later (it was cataloged as number 62). 50th object has been cataloged April 5, 1772 - he had previously observed Cassini, and Messier, who was familiar with his records, looking for it since 1764.
August 10, 1773 Messier discovered a satellite of the Andromeda Galaxy, but for some reason did not include this object in his catalog, the message of this discovery was published only in 1798, and catalog number M110, this object was only in the XX century.
In 1773, Messier object M51 opened, later, Pierre Meshen found that this object consists of two nebulae. Finally, in 1774, was discovered open cluster M52, Messier and then left for a while searching obscure objects.
M53 - M70
In February 1777 Messier discovered M53 and M54 objects, and on July 24 next year, the catalog was introduced M55, Messier who have previously tried to detect the following description of the object detected the Lakaylya.
Object of the M56 was opened in January 1779, when Messier was engaged in the supervision of a comet, an open Bode. The path of this comet was very rich in nebulous objects: around him were the objects that Messier cataloged, numbered M57 (open Antuanom de Pelepua Darko), M59 and M60 (Johann Gotfred Koehler) and M61 (Oriani). Messier discovered M58 itself.
In June 1779 the catalog was included the first object, open Meshenom: M63. In March-April 1780 Messier discovered another 5 objects (M64 - M68). Significantly increased, compared with the first edition, the volume of the catalog encouraged him to publish a second edition. Together with applications that include 2 sites open Messier August 31, 1780, in the directory has been described 70 objects.
M71 - M103
In the second edition of the directory and its contents has not stopped. Total for the year were added more than 32 new units, of which 5 (M73, M84, M86, M87, M93) were discovered by Messier and the rest were found Meshenom (Messier to verify these observations and measurements of objects).
Messier suggested that the third edition of the directory will be described in 100 sites, but at the time of submission of manuscripts for publication Meshen managed to open and describe objects up to M103. Another two, which later was given the designation M108 and M109 were mentioned in a footnote to the description of M97. The third edition of the catalog was published in spring 1781.
Finalization of the catalog
May 11, 1781 in Messier's handwritten notes describe open Meshenom object to which he gave a number M104. Later Meshenom were discovered objects M106 and M107.
Despite the availability of new discoveries, stopped work on Messier's catalog. For this purpose the following reasons: firstly, November 6th, 1781 with Messier was an accident, after which the recovery took a long time, and secondly, in the 1780s searching for obscure objects engaged in the English astronomer William Herschel, who for 20 years period, using much more sophisticated equipment than Messier, has opened more than 2,500 objects. Messier wrote on this subject:
Behind me, the celebrated Herschel published a catalog of 2000 nebulae, which he observed. The study of the sky his way, using an instrument with a large aperture to be ineffective in finding comets. My goal, therefore, differs from it: I need to find a nebula that is visible through a telescope with a focal length of 60 cm In the meantime, I have seen other similar objects. I will publish information about them in the future, putting them in right ascension, to make them easier to find, and that other finders of comets did not experience uncertainty.
However, no new editions of the directory was not followed.
Posthumous addition Messier
Although in the last edition of his lifetime Messier object contained 103, today it includes 110 objects. This is due to the fact that the directory in the XX century was subjected to additions: it were made the objects that Messier observed, but explicitly in the directory is not included.
Information on the four sites M104 - M107 contained in the notes in the margins of the third edition copies of the directory owned by Messier, who was discovered and bought in 1924, Camille Flammarion. They were also mentioned in a letter to Bernoulli Meshena published in the Berlin Astronomical Almanac for 1786. Include these items in the catalog offered Helen Sawyer Hogg, detecting the reprint of the letter.
Objects M108 and M109 were mentioned in a footnote to the description of the object M97, a directory of Owen Gingerich suggested that, in 1953.
The last object, M110, the second satellite of the Andromeda Galaxy, included in the list by Kenneth Glyn Jones, on the grounds that this galaxy Messier observed as early as 1773 (the magazine with these observations was published only in 1798, Messier himself has seen fit to include this object in the catalog).
"Missing" Messier objects
Despite the generally very high quality Messier, based on precise measurements of the positions of each object, often carried out repeatedly, in the place specified in some directory entries, there are no vague objects. Such records relating to the missing objects in the catalog four, for three of them with a high degree of reliability defined object that is actually observed by Messier, but being in a different location than indicated in the catalog.
Messier described the object as a star cluster nebula without having a right ascension 7h 44m 16s and declination +14 ° 50 '8''. However, at this point any star clusters are absent. In 1934, Oswald Thomas suggested in 1959 by TF Morris proved that the error in the catalog caused by an error in the sign, which is made by Messier in the calculation of the object. The object corresponds to two entries in the directory NGC: NGC 2478 (false position) and NGC 2422 (right location).
Messier described the object as a cluster of very faint stars without nebula, having the right ascension 8h 2m 24s and declination +1 ° 16 '42''. As shown by Oswald Thomas and TF Morris, in fact, the object observed by Messier, is 5 ° north, it is currently mapped to the object NGC 2548.
Messier described the object as a nebula without stars in the constellation Virgo, which has the right ascension of 12h 26m 28s and declination -14 ° 57 '6''. In this part of the sky, there are many faint galaxies in the Virgo cluster, but none of them has a sufficient brightness. Owen Gingerich has suggested that Messier could again see the object M58, and a mistake in calculating its location. However, in 1969, William C. Williams has shown that the error was Messier that choosing as a reference point for measuring the galaxy M89, it mistook it with M58, M91 and the object should be mapped directory entry NGC 4548.
Messier described the object as a very faint nebula between the stars of Bootes ο ι and the Dragon, which is located next to the star of the 6th magnitude. The question of whether a given record to any real object, is controversial. American publications consider this site as missing, but most European sources identify it with the galaxy NGC 5866.
The causes of the dispute lie in the contradictions between different sources of information on this site. Meshen originally reported seeing an object, later explained in a letter to Bernoulli, published in the Astronomical Almanac for Berlin in 1786, that the object of M102 is just re-watching the object M101.
However, notes from Messier in the margins of his personal copy of the directory it is known that he had also observed this object by measuring its location. At this point no Messier objects like no, but he presumably, as in the case of M48, made a mistake in determining the location of the object at 5 °; if the calculations to produce correctly calculated the location of the object will correspond to NGC 5866. Thus, even if Meshen really saw the same object twice, Messier when trying to verify his observations could reveal a different object, and if so, then this is the last of the nebula Messier open.
If we proceed from the present astronomical classification, Messier catalog contains:
• 6 of galactic nebulae
• 28 open clusters
• 4 planetary nebulae
• 29 globular clusters
• 40 galaxies
• 3 other object.
The brightest object Messier are the Pleiades (M45, magnitude 1,2 m), the most lackluster - M76, M91 and M98 (magnitude 10,1 m). The largest angular size is the Andromeda Galaxy (M31, 4 ° × 1 °), the largest line - galaxy M101 (diameter 184 000 light years). The smallest angular size have double star M40 (49 ") and the M73 and M76 sites (1 ') Line - Planetary Nebula M76 (0.7 light years).
69 Messier objects belong to our Galaxy: the closest ones are the Pleiades (430 light years), the most distant - a globular cluster M75 (78 000 light years). 41 objects is extragalactic nature: of these 40 objects are galaxies, and one is a globular cluster (M54). The most distant of these objects is a galaxy M109, distant from us at 67.5 million light-years.
Observation of Messier
All 110 Messier objects can be seen even with the simplest astronomical equipment: even an inexperienced observer can do it with 10-inch telescope, and in good seeing conditions all objects (except M91) visible even in binoculars 10 × 50.
On the observation has a strong influence of light pollution: Messier objects, many are clearly visible only in a dark sky, and therefore very accessible to astronomers who live in cities.
Messier objects are available for observation in most of the northern hemisphere astronomers. Some objects in this show only at latitudes below 55 ° (in particular, M7).
At a certain skill and luck, all objects can be observed by Messier in one night. This process is called "Marathon Messier."
All 110 Messier objects are visible only with the points lying between 10 ° and 35 ° north latitude, so the full marathon can not be done anywhere in the world. In addition, all facilities are available for monitoring only twice a year in March and October, when the new moon.
To run a marathon can be used by any supervisory tool, but the use of automatic pointing to an object is prohibited, and shall not be counted with the naked eye observation of the object or a telescope-guide.
The world's first full marathon completed the Messier Jerry Rattli (Arizona) and Rick Hall (CA) - the second an hour later than the first. Since the mid-1980s, a full marathon Messier completed more than 12 American amateur astronomers. Of European astronomers have done a full marathon only Saliger Peter Gurney and Stents, which are carried out surveillance on the island of Tenerife. »»