Classification in Astronomy: Past and Present

Research output: Chapter in Book/Report/Conference proceedingChapter

3 Scopus citations


Astronomers have always classified celestial objects. The ancient Greeks distinguished between asteros, the fixed stars, and planetos, the roving stars. The latter were associated with the Gods and, starting with Plato in his dialog Timaeus, provided the first mathematical models of celestial phenomena. Giovanni Hodierna classified nebulous objects, seen with a Galilean refractor telescope in the mid-seventeenth century into three classes: “Luminosae, " “Nebulosae, " and “Occultae.” A century later, Charles Messier compiled a larger list of nebulae, star clusters and galaxies, but did not attempt a classification. Classification of comets was a significant enterprise in the 19th century: Alexander (1850) considered two groups based on orbit sizes, Lardner (1853) proposed three groups of orbits, and Barnard (1891) divided them into two classes based on morphology.

Original languageEnglish (US)
Title of host publicationAdvances in Machine Learning and Data Mining for Astronomy
PublisherCRC Press
Number of pages8
ISBN (Electronic)9781439841747
ISBN (Print)9781138199309
StatePublished - Jan 1 2012

All Science Journal Classification (ASJC) codes

  • General Computer Science
  • General Physics and Astronomy


Dive into the research topics of 'Classification in Astronomy: Past and Present'. Together they form a unique fingerprint.

Cite this