Article ID: CBB198385705

Algol Anomaly or Careful Observations of its Brightness? The Values Recorded for the Magnitude of Algol in the Medieval Astronomical Corpus (2021)

unapi

The historical evidence from the past two millennia show two problems concerning the star Algol (β Per): First, a critical variation in its brightness from a magnitude m ~ 2 in (1) Ptolemy’s Almagest (2nd century AD) and reported by (2) al-Ṣūfī (10th ct.) through its diminution to m = 4 in (3) the star catalog prepared by the Persian astronomers in service of the Yuan dynasty of China in the 13th ct. to becoming brighter, m = 3, as reported by (4) Ibn al-Shāṭir (14th ct.) and (5) Tycho Brahe (16th ct.). In the early modern period, it returned back to m ~ 2, as reported, for example, by Hevelius and Flamsteed (17th ct.), before the discovery of its periodic variability in 1783. Second, al-Ṣūfī reports it as a red star. We present detailed analyses of the sources (3) and (4) for the test of their accuracy and reliability. Our conservative hypothesis concerning the first problem is that the past astronomers observed the star at various phases of its 3-day period of variability. We reject the reddening to have arisen from the extinction due to either the Earth’s atmosphere or an interstellar medium. For resolving both problems, we instead speculate on astrophysical explanations for the observations. These are: copious dust produced as a result of arrested coronal mass ejections or pulverized planetary debris that resides close to the central binary before being dispersed; and a much-enhanced accretion rate that lead Algol into a W Ser-like state in which the primary was enveloped in an inflated accretion disk. We draw an analogy between the dimming of Algol and the recent dimming of Betelgeuse in order to highlight the value of historical observations for understanding astrophysical phenomena.

...More
Citation URI
https://data.isiscb.org/isis/citation/CBB198385705/

Similar Citations

Article Cenadelli, Davide; (2010)
Solving the Giant Stars Problem: Theories of Stellar Evolution from the 1930s to the 1950s (/isis/citation/CBB000932990/)

Book Harm J. Habing; (2018)
The Birth of Modern Astronomy (/isis/citation/CBB858392112/)

Book Hearnshaw, J. B.; (2014)
The Analysis of Starlight: Two Centuries of Astronomical Spectroscopy (/isis/citation/CBB001551779/)

Article Nauenberg, Michael; (2008)
Edmund C. Stoner and the Discovery of the Maximum Mass of White Dwarfs (/isis/citation/CBB000930130/)

Article Cenadelli, Davide; (2008)
The Hydrogen Abundance in Stars: A First Major Step for Quantitative Astrophysics (/isis/citation/CBB001034774/)

Book Katia Moskvitch; (2020)
Neutron Stars: The Quest to Understand the Zombies of the Cosmos (/isis/citation/CBB559459540/)

Chapter Michael Rotondo; (2016)
On the concept of degenerate stars: the case of white dwarfs (/isis/citation/CBB672582700/)

Article Stanley, Matthew; (2007)
So Simple a Thing as a Star: The Eddington--Jeans Debate over Astrophysical Phenomenology (/isis/citation/CBB000771301/)

Book Ileana Chinnici; (2019)
Decoding the Stars: A Biography of Angelo Secchi, Jesuit and Scientist (/isis/citation/CBB547940053/)

Article Holberg, J. B.; (2009)
The Discovery of the Existence of White Dwarf Stars: 1862 to 1930 (/isis/citation/CBB000932194/)

Article S. Balachandra Rao; Rupa K.; Padmaja Venugopal; (2016)
Heliacal Rising of Canopus in Indian Astronomy (/isis/citation/CBB130624835/)

Article Wesemael, François; Racine, René; (2008)
Why Was the Companion of Sirius Not Seen Prior to 1862? (/isis/citation/CBB000930124/)

Book Clifford Cunningham; (2016)
Discovery of the First Asteroid, Ceres: Historical Studies in Asteroid Research (/isis/citation/CBB700446822/)

Article Kuz'min, A. V.; (2006)
The First Optical Observations of Stars: Galileo Galilei or Tycho Brahe? (/isis/citation/CBB000930313/)

Article Teichmann, Jūrgen; Stinner, Arthur; (2014)
From William Hyde Wollaston to Alexander von Humboldt---Star Spectra and Celestial Landscape (/isis/citation/CBB001320983/)

Article Christián C. Carman; (2019)
A Possible Date for Ptolemy’s Development of a Model for the Second Lunar Anomaly (/isis/citation/CBB205575975/)

Article John Steele; (2019)
An Early Compilation of Saturn Observations from Babylon (/isis/citation/CBB365653299/)

Chapter Fantham, Elaine; (2011)
More Sentiment than Science: Roman Stargazing before and after Manilius (/isis/citation/CBB001201028/)

Authors & Contributors
Cenadelli, Davide
Rotondo, Michael
Moskvitch, Katia
Habing, Harm J.
Stanley, Matthew
Wesemael, François
Concepts
Astronomy
Stars; stellar astronomy
Observation
Astrophysics
Cosmology
Science and culture
Time Periods
20th century, early
19th century
Ancient
21st century
20th century, late
20th century
Places
England
Greece
Europe
Rome (Italy)
Mesopotamia
Chile
Institutions
University of Leeds
Jesuits (Society of Jesus)
Cambridge University
Comments

Be the first to comment!

{{ comment.created_by.username }} on {{ comment.created_on | date:'medium' }}

Log in or register to comment