Editing Hipparchus (section)

===Stellar magnitude===
Hipparchus is conjectured to have ranked the [[apparent magnitude]]s of stars on a numerical scale from 1, the brightest, to 6, the faintest.{{sfn|Toomer|1984|loc=[https://archive.org/details/ptolemysalmagest0000ptol/page/16/ {{p.|16}}]: "The magnitudes range (according to a system which certainly precedes Ptolemy, but is only conjecturally attributed to Hipparchus) from 1 to 6.", {{pgs|341–399}}}} This hypothesis is based on the vague statement by Pliny the Elder but cannot be proven by the data in Hipparchus's commentary on Aratus's poem. In this only work by his hand that has survived until today, he does not use the magnitude scale but estimates brightnesses unsystematically. However, this does not prove or disprove anything because the commentary might be an early work while the magnitude scale could have been introduced later.{{r|hoffman-befunde}} Yet, it was proven that the error bars of magnitudes in ancient star catalogue is 1.5 mag which suggests that these numbers are not based on measurements.<ref>{{Cite journal |last1=Protte |first1=Philipp |last2=Hoffmann |first2=Susanne M. |date=2020 |title=Accuracy of magnitudes in pre-telescopic star catalogs |url=https://onlinelibrary.wiley.com/doi/10.1002/asna.202013803 |journal=Astronomische Nachrichten |language=en |volume=341 |issue=8 |pages=827–840 |doi=10.1002/asna.202013803 |issn=0004-6337|arxiv=2008.04967 |bibcode=2020AN....341..827P }}</ref> There were several suggestions on measurement methodologies and feasibility studies.<ref>Protte Ph. and Hoffmann S.M. (2021). Pre-Telescopic star catalogues – Accuracy in magnitudes and positions, in Wolfschmidt and Hoffmann [Hrsg.]: Applied and Computational History of Astronomy – Proceedings of the Splinter Meeting in the Astronomische Gesellschaft, Sept. 25. Nuncius Hamburgensis – Beiträge zur Geschichte der Naturwissenschaften; Vol. 55, tredition, Hamburg, 109-144</ref> In all cases, the error bars would be smaller. Hence, Hoffmann (2022) suggested that the magnitudes were not measured at all but mere estimates for globe makers to improve pattern recognition on globes as astronomer's computing machines.<ref>Hoffmann, S.M. (2022). Essay: On Ptolemy’s stellar magnitudes, in Hoffmann and Wolfschmidt (eds.). Astronomy in Culture – Cultures of Astronomy, tredition/ OpenScienceTechnology, Hamburg/ Berlin, 426-429</ref> 

Nevertheless, this system certainly precedes [[Ptolemy]], who used it extensively about AD 150.{{sfn|Toomer|1984|loc=[https://archive.org/details/ptolemysalmagest0000ptol/page/16/ {{p.|16}}]: "The magnitudes range (according to a system which certainly precedes Ptolemy, but is only conjecturally attributed to Hipparchus) from 1 to 6.", {{pgs|341–399}}}} This system was made more precise and extended by [[N. R. Pogson]] in 1856, who placed the magnitudes on a logarithmic scale, making magnitude 1 stars 100 times brighter than magnitude 6 stars, thus each magnitude is {{radic|100|5}} or 2.512 times brighter than the next faintest magnitude.<ref>{{cite journal|last=Pogson|first=N. R.|author-link=Norman Robert Pogson|date=1856|title=Magnitudes of Thirty-six of the Minor Planets for the first day of each month of the year 1857|url=http://articles.adsabs.harvard.edu//full/seri/MNRAS/0017//0000012.000.html|journal=[[Monthly Notices of the Royal Astronomical Society|MNRAS]]|volume=17|page=12|bibcode=1856MNRAS..17...12P|doi=10.1093/mnras/17.1.12|doi-access=free}}</ref>