Discovery history of deep space objects

A long time ago, as long as it was not cloudy, people could see stars in the night sky. In prehistoric times, there was almost no light pollution in most parts of the earth. Our ancestors could see very dim starlight, and some celestial bodies are classified as deep-space celestial bodies by people today. It seems that some of these celestial bodies are as old as our human history. Of course, the most prominent of these "celestial bodies" is a galaxy, our own Milky Way; However, we don't count. Similarly, we will not consider the most prominent "moving" cluster-Ursa major, which is composed of most stars in the famous "Big Dipper" and constitutes the most prominent part of Ursa major. First of all, most modern people don't regard them as "deep space objects". Secondly, their essence, such as the Milky Way is a galaxy and the star in Ursa Major is a physical cluster, was not understood until modern times, so this neglect is appropriate.

Some bright star clusters have been known for a long time, even before historical records. Of course, they include the Pleiades (M45) and the Pleiades in Taurus, which are also visible to the naked eye and have been recorded for a long time (for example, the earliest exact record of the Pleiades was left by hesiod between about BC 1000 and 700). In the southern hemisphere, two Magellanic clouds (LMC-Large Magellanic Cloud and SMC-Magellanic Cloud) were discovered a long time ago, but there are not many ancient records preserved in the southern hemisphere.

Aristotle may have made an ancient observation record of the open cluster M4 1 around 325 BC. This makes this cluster the darkest object in ancient observation records. Burnham thinks that according to the statement written by J.E. Gore quoted by P. Doig in 1925, it is possible that Aristotle also observed M39 in Cygnus at that time and described it as a "comet-like object". Hipparchus, a famous Greek astronomer, made observations in Rhodes from BC 146 to BC 127. He was the first astronomer to write a catalogue; He observed a "new star" in Scorpio in 134 BC, which may have prompted him to compile this catalogue. His catalog includes two "cloud-like objects", Ghost Cluster (M44) and Perseid Binary Cluster, which is now called Perseid h+chi(NGC 869+884, not in messier catalog).

Ptolemy, in his Theory of Grand Synthesis (usually called "Astronomical Masterpieces") written in A.D.127-15/year, listed seven celestial bodies, three of which were ordinary stars, not physical celestial bodies, and two were inherited from Hipparchus. There are two new ones: one is the nebula behind Scorpion Stinger, which is now certified as a remarkable open cluster M7, named Ptolemy Cluster by some modern authors, and the other is a late cluster, which is now compiled as Melotte11(but not in Mes).

The first real "nebula" object discovered and recorded was the Andromeda galaxy (M3 1), which was observed around 905 AD and recorded by Persian astronomer Al Sufi in his Book of Stars in 964 AD. He also mentioned a "cloud-like star", which is located more than 2 degrees north of Delta in Vela, and it is also a quite remarkable open cluster IC 239 1, and Omicron in Vela. The book also includes six celestial bodies of Ptolemy, and a new "star" in Fox (actually brocchi Cluster, Collinde 399, also nicknamed "Hanger Cluster"), so he recorded nine celestial bodies.

Unlike other deep-space objects mentioned here, ancient astronomers in China and North America (probably) observed and recorded a supernova explosion on July 4, 1054; This supernova created the Crab Nebula (M 1), which is one of the most interesting deep space objects.

Since then, no new deep space objects have been discovered until 15 19, when Magellan reported seeing two Magellanic clouds, one large and one small. This made the total number of deep space objects observed by people reach 1 1 before Galileo introduced the telescope into astronomy in 1609, although Al Sufei's work was not known to most people at that time. Through the telescope, Galileo discovered that the ghost cluster (M44) is not a nebula, but a cluster. Nicolas-Claude Fabbri de perris (1580- 1637) discovered the first real nebula-Orion Nebula M42 in 16 10, which is also the first deep space object discovered by telescope. The Catholic astronomer J.-B. Cysatus (1588-1657) independently discovered M42 in 16 1 1 year, but this celestial body was unknown to the public for a long time. Shortly thereafter, in 16 12, Simon Marius (1570- 1624) discovered (independently rediscovered) the Andromeda galaxy (then Andromeda Nebula, M3 1).

Giovanni Batista Hotchner, the court astronomer of the Duke of Monte Chiaro (1597- 1660), compiled a catalogue with 40 entries. He found this catalogue with a simple Galileo refractor, which was enlarged by 20 times, including 19 real cloud-like objects. This directory is published in 1654. However, this history was forgotten for a long time, and it was not rediscovered until the early 1960s (published by Serio, Indo-Dorato and Nastasi in Volume 45 (1February 1985) and Volume 50 (1August 1986) of The History of Astrology). This catalogue includes the independently rediscovered Andromeda Nebula (M3 1), Orion Nebula (M42) and brocchi Cluster. It describes for the first time the moving star cluster of Perseus α, and at least nine objects (possibly 13 or even 15) that he really discovered: it is determined that the objects discovered by him are M4 1, M47, NGC 2362, NGC 623 1 and NGC6550/. It is probable that M33, M34, NGC 752, NGC 245 1 were all discovered by him, and NGC 26544 was also discovered by him.

Christiaan huygens independently rediscovered the Orion Nebula M42 in 1656, which made this celestial body widely known. He also found three stars in the Orion quadrupole nebula.

Johan Hevel or Hevelke from Dantzig (better known as Hevelius (Jahannes Hewelius), 16 1 1-87) compiled the document containing 156.

Deep sky object

After his death, the catalogue of four stars "Celestial Table E" was published together with his star map. He also summarized a list of 16 entries, two of which are real celestial bodies (Andromeda galaxy m3 1 and ghost cluster M44), and the other 14 are all stars or do not exist at all. Deleusme and messier spent a lot of time looking for these "nebulae"; Messier thinks he has identified a pair of binary stars in Ursa Major (M40)-as we know, he may not have recognized the binary stars seen by Hevelius. Hevelius was the first person to see M22, but it is generally believed that this globular cluster, which was first known to mankind, was discovered by Abraham Ihle in 1665.

In john flamsteed (1646- 17 19), published in 17 12, revised in 1725, several "nebulae" were mentioned. Most of them are known celestial bodies at that time (late cluster Mel11,double star cluster of Perseus h+chi, M3 1, M42), and there are three independently discovered celestial bodies, including the rediscovered unknown Hodierna celestial bodies NGC 6530 (associated with M8) and M465438. NGC 2244 around the star 12 in the unicorn (the cluster related to NGC 2237-9 in the Rose Nebula, neither of which is in messier's catalog).

Gottfried Kirsch (1639- 17 10), an astronomical observer in Berlin, is famous for observing stars and comets. He found M 168 1 in 65438.

Edmond Halley (1656- 1742) published a list of six "bright spots" in Philosophical Transactions of the Royal Society 17 15. These include the globular nebula Omega Centauri (discovered on a trip to Helena Peak in 1677) and M13 (discovered in1714), as well as previously known celestial bodies M42, M3 1, M22 and M/kl.

Jean-Jacques Dortous de Mairan (1678-1771) discovered a nebula-like substance around a star on the north side of Orion nebula before 173 1, which was later called M43 (this discovery was made at/kloc). Shortly thereafter, john Bevis (1695- 177 1) discovered the crab nebula M 1. He also created a star map, which he called "The Star Map of Britain", which was completed in 1750. However, due to the bankruptcy of the publishing house, only one or two printed copies were published, and the accompanying catalogue was never published. Messier must have got a copy of this map, because he mentioned "Atlas of Britain" many times in his descriptions of M 1, m1,M 13, M22, M3 1 and M35. Oddly, Kenneth Glyn Jones attributed the discovery of M35 to de Cheseaux in 1746, although Bevis seems to have seen it before because it appeared in his star map.

William Deleusme (1657- 1735) published a list of 16 cloud-like objects in the Journal of Philosophy of the Royal Society (1733), of which 14 came from Hevelius and the other two came from Harley. Only two celestial bodies are real (M3 1 and M7), and the others are either non-existent or boring stars, which puzzles other astronomers (including messier) who use this list. This list was published again in the Journal of the French Academy of Sciences in 1734, and was included in De Maupertuis's Discussion on the Celestial Map in 1742.

Around 1746, Philip Lois de Chesau (17 18-5 1) observed several star clusters and "cloud stars" and compiled their positions into a catalog. According to Kenneth Glyn Jones and the Weber Institution's Handbook for Deep Space Observers, Volume 3 (Evacuation and Globular Clusters), eight of them were discovered for the first time: IC 4665 (second place, uncertain) and NGC 6633 (third place). M16 (No.4), M25 (No.5), M35( 12, but see john Bevis's comments), m 7 1( 13), M4( 19), M. In addition, he independently rediscovered M6 (No.1), NGC 623 1 (No.9) and M22 (No.17). De Chesau gave this list to Reaumur, who published it in the French Academy of Sciences on August 6th, 1746, but it was not published in other forms. It was not until 1884 was investigated in Bigourdan that more people began to know. In addition to observing the cloud-like light spots in the sky, De Chesau may be the first person to express Olbers's paradox in a formula. Jean-Dominique Maraldi (1709-88), also known as Maraldi II, discovered two globular clusters: 1746, M 15, 1746 and M2+0. Le Gentil (full name Guillaume- Joseph-hyacinthus orientalis e-Jean-Baptiste le Gentile de la Galazier, 1725-92) discovered the companion galaxy M32 of Andromeda on June 29th, 749. That year, he also discovered the gas nebula M8, that is, the lagoon nebula (the cluster in this nebula has been discovered by Flamsteed before, see the above picture), and may also discover the globular cluster NGC 67 12. He also independently discovered the Hodierna objects M36 and M38. Abbe Nicholas Louis de Lacaille (Lacaille, 17 13-62) went to South Africa in 175 1-52, where he observed the stars in the southern sky and deep space objects, created several southern constellations (most of which are still in use) and compiled 40. Twenty-five of them were discovered for the first time, and at least two of them were independently rediscovered. The first celestial bodies discovered in Lacaille mainly include NGC 3372 of Eta nebula in carina, azalea 47 of globular cluster (NGC104), NGC 2070 of tarantula nebula in large magellanic cloud and M83, a spiral galaxy discovered for the first time outside this galaxy group. This is the last deep-space celestial body discovered by Charles Messier (messier) (1730- 18 17) before the compilation of the catalog. 1764, messier discovered M3, which was the first deep space object he discovered. For more than a decade, Charles Messier searched for clusters and cloud-like objects alone. During this period, he discovered 27 celestial bodies, 25 of which are really deep space objects (the other two are the Sagittarius nebula M24 and the binary star M40).

Since then, until 178 1 year, messier himself discovered 18 cloud-like objects for the first time (17 deep-space objects, plus a tetrad star M73), making the total number of objects he discovered for the first time reach 43, and another 20 objects were discovered independently.

At the end of 1774, Johann Elert Bode (1747-1826) successfully joined the search for new foggy celestial bodies: he discovered m 865438+ on the last day of the year (65438+February 3 1). Bode compiled a list of deep-space celestial bodies with 75 entries, which was published in 1777 almanac 1779, entitled "Summary of Cloudy Stars and Clusters Discovered So far". However, according to Kenneth Glyn Jones, this list is full of nonexistent celestial bodies and stars collected from Hevelius and others; It only contains about 50 real celestial bodies. The two celestial bodies he later discovered, M92 and M64, were published on the Jahrbuch of 1782 at the end of 1779. The other two celestial bodies, M48 and IC 4665, discovered independently by Bode were published in his 1782 Star Map and Catalogue Vorstellung der Gestirne. About five years later 1779, while messier and Bode were still actively compiling their catalogues, five other astronomers joined the "club" with the successful discovery of deep space objects: Antoine Darquier de Pellepoix of Toulouse discovered the ring nebula M57 in 65438+ 10, a little earlier than messier; They were all discovered while tracking the comet (1779 comet Bode). British astronomer Edward Piggot (1753- 1824) discovered M64 on 1779 on March 23rd, only 1780 days earlier than Bode (1779). John gottfried Koehler (Bode K&; OumlHler, 1745- 180 1) This year at the latest, M67,1April 7791,M59 and M60 are tracking Bode/kloc-0. When messier discovered M58 in this area, barnabas Ogliani (1752- 1832) first discovered M6 1. Koehler published a list of 20 entries in 1779. Finally, messier's friend Pierre Michelin (1744- 1804) started his astronomical observation career, and in June of 1779, he discovered M63, which was the first celestial body he discovered. Subsequently, Mechain discovered about 25 celestial bodies discovered for the first time. Because of his close cooperation with Charles Messier in observation, most of these celestial bodies were listed in messier's catalogue. Because he did tell messier all his discoveries, Helen Sawyer-Hogg decided to add three other celestial bodies to messier's catalog in 1947 (M 105 to M 107).

As an important piece in the history of deep space discovery, the final version of messier catalog containing 65,438+003 celestial bodies was published in the French Astronomy des Temps in 65,438+07,865,438+0. Some messier's personal notes and1Mechain's letter to Bernoulli on May 6, 783 mentioned that the celestial bodies were expanded into messier's catalog, bringing the total number of celestial bodies to 1 10, all of which are real celestial bodies (although four celestial bodies have been missing for more than a century, there are still some disputes about M 102). This catalog contains most nebulae, clusters and galaxies discovered before April 1782, of which M 107 is the last celestial body discovered in messier (discovered by Pierre Mechain).

Messier catalog really left a deep impression on the great German-English astronomer William Herschel (1738-1822). He gradually became famous for discovering Neptune in 178 1 year. 17811On February 7th, Herschel got a catalogue of messier from his friend william watson. At that time, he was an organist in Bath (he didn't give up this job until May 1782) and a skilled telescope maker. 1789 On August 28th, he assembled a giant telescope with a diameter of 48 inches and a focal length of 40 feet (on the first day of observation with this telescope, he discovered a new satellite of Saturn, Enceladus), and used this telescope to conduct a large-scale search in the visible sky area of Britain (that is, the northern sky). Herschel published a catalog of more than 2,500 celestial bodies in three steps, most of which are real deep-space celestial bodies. He used the best telescope at that time, so he had no competitors at all. His observation was completed with the help of his sister caroline lucretia herschel (caroline herschel) (1750- 1848). She is also an enthusiastic observer. She found many clusters and nebulae in Herschel's catalogue (including the independently rediscovered M 1 10). And the independently rediscovered missing messier open cluster M48 (H VI.22), and eight comets were also discovered.

William Herschel divides cloud-like objects into eight categories: bright nebula, dark nebula, extremely dark nebula, planetary nebula, very dense star-rich cloud, dense cluster composed of large and small stars (that is, bright and dark), and loose and sparse cluster composed of stars. Because the nature of these celestial bodies was not clear at that time, this classification is more historic today.

William (and Caroline) Herschel actually discovered almost all the celestial bodies in the northern sky around 1800. But the sky in the southern hemisphere is still waiting for people to explore. James Dunlop (1795- 1848) made his first large-scale observation in the southern hemisphere after Lacaille. Together with Sir Thomas McDougall Brisbane (owner of Brisbane Observatory in Parramatta (1823- 1827), he came to New South Wales, Australia in 182 1 year, where he compiled a star map (Brisbane catalog), including 70,000 in the southern sky. He arranged the deep-space objects discovered at that time into a 629-entry "Southern Sky Nebula Cluster Table Observed in New South Wales". This catalogue was given to John Herschel, the son of William Herschel, who published it in the Royal Society 1827. Because of this work, Dunlop won the gold medal of the Royal Astronomical Society and the Lalander Prize of the French Academy of Sciences. Then, these awards can't cover up a large number of "non-existent" celestial bodies in his catalog, and the poor description of celestial bodies, so that it is almost impossible to accurately identify them later: only about half of the entries can be associated with real celestial bodies.

John Frederick William (John) Herschel (John Herschel) (1792- 187 1) inherited his father's work and added 525 new entries (North Ladder) to the catalogue published by 1833. However, John Herschel also wanted to compile the South Catalogue. 1October 3rd 1883+65438+65438, he and his family boarded a passenger ship bound for the Cape of Good Hope in South Africa and arrived at their destination on March 4th 1834. In the next few days, he focused on the southern sky. He compiled a catalogue of 17 13 entries and published it in 1847. Obviously, he compiled the discoveries of him and his father, as well as the deep space objects discovered by others, into his general catalogue, which contained more than 5,000 entries.

Herschel's work finally summed up the era of the great discovery of "nebulae" (and clusters). However, it will take a long time to reveal the properties of different deep space objects, and new research methods (especially photography and spectral analysis) are needed: the cloud properties of the "real" nebula were revealed by William Huggins (1824- 19 10), a British amateur astronomer and pioneer in spectral analysis, in the 1960s. It was not until 1920s that Edwin Hubble (1889- 1953) really revealed that the essence of a galaxy is actually an independent "island universe" like our Milky Way.