Comets and other transients | Meteorology & Beyond

Astronomical "transients" are objects that occur in the sky and vanish after a while. They are visible only for a period of time.

Modern astronomers classify them as:

comets (objects of the solar system)
stellar transients
- eruptions on surfaces of stars (novae, variable stars)
- explosions of stars (supernovae, mergers)

but ancient astronomers did not know what they were seeing: for them, they were miraculous appearances.

Aristotle, Lucretius and Seneca mentioned some comets in combination with earthquakes, waves and other phenomena on Earth but no stellar transients. In a fruitful collaboration, two other projects revisited many records of transients in chronicles -- most of them originating in Old China and its colonies because of their usage of the "guest stars" for political omens.

These projects were:

Centro de Astrofísica, Universidad de Valparaíso, Chile: financial support by FONDECYT regular No. 1170566
Applied and Computational Historical Astronomy, Michael-Stifel-Center Jena, Germany - funded by the Free State of Thuringia and University of Jena, Germany

Comets

Stellar Transients

Comets in Antiquity

Comets

Editions and Translations used

Louis, P. (1982) Aristote. Météorologiques, tom. I & II, Paris: Les Belles Lettres.

Hine, H. M. (1996) L. Annaei Senecae Naturalium Quaestionum Libros, Stuttgart / Leipzig: Teubner.

Godwin, J. (1991) Lucretius De Rerum Natura VI, edited with translation and commentary, Warminster: Aris & Phillips Ltd.

Great Comet
winter 373 / 372 BCE

Aristotle mentions this comet in connection with weather phenomena.

Aristotle, METE I 6.343a35-b6:

Moreover the statement that a comet only appears in the north, with the sun at the summer solstice, is not true either. The great comet which appeared at the time of the earthquake in Achaea [1] and the tidal wave rose due west [apo dusmōn tōn isēmerinōn] [2]; and many have been known to appear in the south. Again in the archonship of Euclees, son of Molon, at Athens [3] there appeared a comet in the north in the month Gamelion [January/February], the sun being about the winter solstice.

Cf. Seneca, NQ VI 23.4:

This Callisthenes, in the books where he describes the inundation of Helice and Buris,[4] and the event that drove them into the sea, or the sea onto them, says what has already been said in an earlier section: […]

[1]
"According to Strabo (VIII 7), this earthquake (which was also felt at Delphi where the temple of Apollo was destroyed) took place two years before the battle of Leuctra, therefore in 373, when Aristotle was ten years old: it buried the city of Boura and the subsequent tidal wave took Helice away. This catastrophe had strongly struck the spirits: Aristotle speaks about it again at 368b6." English translation of the comment found in the edition of Louis.

[2]
"The equinox setting indicates the direction due west. The comet in question is perhaps Halley's Comet, which reappears on average every 75 years and may have been visible around 373 BCE." English translation of the comment found in the edition of Louis.

[3]

At 427/6 BCE according to Louis.

[4]
"Helice and Buris (also called Bura) were towns in Achaea, on the south of the Gulf of Corinth. See FGH, 124F19." Comment found in Hine (2010).

and

Seneca, NQ VII 16.2.4-3.6:

Ephorus is not someone of the most scrupulous reliability: he is often deceived, more often he deceives, as in the case of this comet, which was watched by the eyes of all humankind, because it brought about the occurrence of a major event, drowning Helice and Bura at its appearance. He says it separated into two stars; but apart from him no one has reported this. Who could have observed that moment at which the comet broke up and was reduced to two pieces? How come, if there is somebody who has seen a comet being split in two, that nobody has seen one forming from two stars? Why did he not add what stars it divided into, since it must have been some of the five stars?

Comet 60 CE

Seneca, Naturales Quaestiones VII 28.2-3:

To show you that this is so, a comet does not threaten wind or rain as soon as it appears, as Aristotle says, but it makes the whole year suspect; which shows that it does not derive signs from the immediate locality for the immediate locality, but it has signs laid down and provided for by the laws of the world. The comet that appeared in the consulship of Paterculus and Vopiscus [1] did what was predicted by Aristotle and Theophrastus; for there were violent, continual storms everywhere, while in Achaea and Macedonia cities were destroyed by earthquakes.

[1]

60 CE according to the Hine translation.

Comet 147 BCE

Seneca, NQ VII 15.1.3-8:

After the death of Demetrius, king of Syria, whose children were Demetrius and Antiochus, shortly before the Achaean war [1], a comet shone brightly, no smaller than the sun. At first it was a fiery, reddish circle, emitting bright light sufficient to overcome the darkness; then gradually its size contracted, and its brightness faded, and finally it disappeared totally.

[1]

"Demetrius I of Syria lived from 187–150 BCE, and the war between the Achaean confederacy and Rome was in 146–145. The comet appeared in 147 according to Obsequens 20." Comment found in Hine (2010).

Comet

The exact date is unknown. The "reign of Attalus" refers to Attalus III of Pergamum who has been king between 138 and 133 BCE.

(cf. comment in the 2010 translation of Hine)

Seneca, Naturales Quaestiones VII 15.2.1-4:

In the reign of Attalus, to begin with, a comet of modest size appeared; later it rose higher, spread out, and reached as far as the equinoctial circle, extending to enormous length, as big as the stretch of the heavens called the Milky Way.

Lexicon of Stellar Transients
(some examples)

Stellar Transiens

ALL

Editions, Translations and Selections used

Clark, D., & Stephenson, F. 1977, The Historical Supernovae, Oxford (Pergamon).
Hertzog, K. P. 1986, Observatory, 106, 38.
Ho, P. Y. 1962, Vistas Astron., 5, 127.Pskovskii, Y. P. 1972, Soviet Astron., 16(1), 23.
Hsi, T.-T. 1957, Smithonian Contributions to Astrophysics, 2, 109.

Editions, Translations and Selections used

Stephenson, F. R., & Green, D. A. 2002, Historical Supernovae and their Remnants, Oxford University Press (New York)
Xi, Z.-Z., & Po, S.-J. 1966, Science, 154(3749), 597.
Xu, Z., Pankenier, D.W., & Jiang, Y. 2000, East Asian Archaeoastronomy, Gordon and Breach Science Publishers (Amsterdam).

Fuzzy Star 329 CE

Source

Suggested Idenfications

"Emperor Cheng of Jin, 4th year of the Xianhe reign period, 7th month. There was a fuzzy star in the northwest. after 23 days ot was extinguished."

[Song shu, Tianwen zhi, ch. 24]

"Emperor Cheng of Jin, 4th year of the Xianhe reign period, 7th month. There was a fuzzy star in the northwest trespassing against Dou. After 23 days it was extinguished."

[Jin shu, Tianwen zhi, ch. 13]

Maps

Guest star -47

"Emperor Yuan of Han, 1st year of the Chuyuan reign period, the 4th month [May 3 to 31]. There was a guest star as large as a melon with a bluish-white color about four chi east of the second star of Nandou [LM 8]."

Han shu, Tianwen zhi, ch. 26
(xu et al. (2000, 130)

Nandou

Suggestions to identify

Source

Maps

(computed by SMH (2020) for paper series Hoffmann and Vogt (2020) in MNRAS

Guest Star 369 CE

Translations from Chinese chronicles:

"Zigong" is the constellation of the Purple Palace, a huge area in the sky, almost the whole circumpolar region. The "west wall" of this palace-constellation is a well-defined chain of star.

Suggested Identifications

References:

Hoffmann and Vogt (2020)

Supernova remnants (SNRs, red) and pulsars (PSRs, blue) in the area or "the west wall of Zigong"

Cataclysmic variables (CVs, green) and nebulae classified as "planetary nebulae, PNe" in the area of "the west wall of Zigong":

Guest Star 1181

Source

"Emperor Xiaozong of Song, 8th year of the Chunxi reign period, 6th month, day jisi [6]. A guest star emerged in lunar mansion Kui [LM 15] and trespassed against the stars of Chuanshe. [It lasted] until day guiyou [10] in the 1st month of the following year, in all for a total of 185 days, and only then was it extinguished."

[China: Song shi, Tianwen zhi, ch. 56]

"Emperor Shizong of Song, 21st year of the Dading reign period, 6th month, day jiaxu [11]. A guest star appeared in HUagai. After a total of 156 days it was extinguished."

[China: Song shi, Tianwen zhi, ch. 20]

"1st day of the Yowa reign period (5th year of the Jijo reign period), 6th month, 25th day, gengwu [7]. At the hour of xu (LT = 19-21), a guest star appeared in the north to Wangliang guarding Chuanshe."

[Japan: Mei getsu ki, ch. 23]

"1st year of the Yowa reign period, 6th month, 25th day gengwu [7]. At the hour of xu [LT = 19-21h], a guest star appeared in the gen direction (NE). Like Saturn it was bluish-red and had sharp horns. This was unprecedented since the 3rd year of the Kanko reign period (1006)..."

[Japan: Azuma kagami, ch. 2]

Reference (all quoted from):

Xu et al. (2000). pages 140-141

Suggested Identifications

Reference:

Hoffmann and Vogt 2020 A new approach to generate a catalogue of potential historical novae, AN, 341, 79-98
Hoffmann and Vogt (2021). Review on the search for historical novae and several byproducts, in Wolfschmidt and Hoffmann [Hrsg.]: Applied and Computational Historical Astronomy – Proceedings of the Splinter Meeting in the Astronomische Gesellschaft, Sept. 25, 2020. Nuncius Hamburgensis – Beiträge zur Geschichte der Naturwissenschaften; Vol. 55, tredition, Hamburg 2021, 238-294

Eratosthenes'
additional star

Eratosthenes claims that the brightest star of the Scorpion is at its northern claw. This is confusing because the brightest star in this constellation is Antares, the red supergiant in the heart of the Scorpion.

Pseudo-Eratosthenes, Katasterismi:

FIGURE first published in Hoffman (2017, 534)
blue: "Claws of Scorpius" (Libra) in the Almagest.
red: stars mentioned in Eratosthenes
yellow: additional star in the "Claws" - he describes a position more north but as it unknown where exactly, we indicate it "in Claws".

Conclusion

The object turned out as neither a stellar transient nor a comet but - highly likely - a repesentation of planet Saturn in its "standard position on ancient celestial maps.

References

Pamias & Geus (2002). Eratosthenes, Sternsagen, Utopica, Oberhaid.
Pamias & Zucker (2013). Ératosthène de Cyrène, Catastérismes, Les Belles Lettre, Paris
Hoffmann (2017). Hipparchs Himmelsglobus. Springer, Wiesbaden/ New York
Hoffmann & Vogt (2021). Review on the search for historical novae and several byproducts. in Wolfschmidt & Hoffmann, Nuncius Hamburgenis, tredition, Hamburg, 267-269

Hipparchus' "new star"

The original work of Hipparchus in which he reports this observation is not preserved. Only secondary sources report.

Pliny, NH II 24-26:

This same Hipparchus, who can never be sufficiently commended, (. . .), discovered a new star that was produced in his own age, and, by observing its motions on the day in which it shone, he was led to doubt whether it does not often happen, that those stars have motion which we suppose to be fixed. And the same individual attempted, what might seem presumptuous even in a deity, viz. to number the stars for posterity and to express their relations by appropriate names; having previously devised instruments, by which he might mark the places and the magnitudes of each individual star. In this way it might be easily discovered, not only whether they were destroyed or produced, but whether they changed their relative positions, and likewise, whether they were increased or diminished; the heavens being thus left as an inheritance to any one, who might be found competent to complete his plan.

China: Han shu, Tianwen zhi, ch. 27

Emperor Wu of Han, 1st year of the Yuan-guang reign period, 6th month [summer 134 BCE, equaling -133].

A guest star was seen at Fang.

commentary [SMH]
previous guest star: summer 204 BCE

subsequent one: between 110 and 105 BCE,

both in Han shu

Identifications

Conclusion

I don't subscribe to the point of view that Hipparchus saw a comet. This would not be an argument for a star catalogue.

However, there is neither a convincing remnant of a supernova nor any candidate for a classical nova. My co-author's (N. Vogt's) suggestions of candidates for longterm recurrent novae require an object type that is not yet known and therefore uncertain.

I consider the case still unexplained.

References

Hoffmann (2017).Hipparchs Himmelsglobus – Ein Bindeglied in der babylonisch-griechischen Astrometrie?, Reihe: Research, Springer Verlag, Wiesbaden, New York
Hoffmann & Vogt (2021). Review on the search for historical novae and several byproducts, in Wolfschmidt and Hoffmann [Hrsg.]: Applied and Computational History of Astronomy – Proceedings of the Splinter Meeting in the Astronomische Gesellschaft, Sept. 25, 2020. Nuncius Hamburgensis – Beiträge zur Geschichte der Naturwissenschaften; Vol. 55, tredition, Hamburg 2021, 238-294
Hoffmann and Vogt (2022). A Search for recurrent novae among Far Eastern guest stars, New Astronomy, Vol 92, 2022, 101722
Xu, Pankenier and Jiang (2000). East Asian Archaeoastronomy. Historical Records of Astronomical Observations of China, Japan and Korea. Gordon and Breach Science Publishers.

Large Yellow Star 396

Source

Emperor Taizu of Wei, 1st year of the Huangshi reign period ...

prior to this, a large yellow star emerged in the space of Mao [LM 18] and Bi [LM 19] for more than 50 days...

in winter, 11th month, the yellow star appeared again.

[Xu et al. 2000, 133]

Identifications

Hertzog 1986 suggested it as an outburst of a white dwarf-red dwarf binary system in Taurus.

Hoffmann, Vogt and Protte (2020) suggest that this was not a stellar transient but an observation of Venus that was used in the omen text for the chronicle.