Modern Counterparts
The most important modern development has been the Hipparcos satellite, operated between 1989-93, which observed around 118,000 stars over the whole sky, and led to three very accurate star catalogues:
- Hipparcos Catalogue (118,000 stars, average accuracy ±0.001")
- Tycho Catalogue (about 1,050,000 stars, with accuracy ±0.03"), and
- Tycho-2 Catalogue (about 2,500,000 stars) which was improved for double star effects and proper motions using the Astrographic Catalogue observations.
In the next decade a further step is planned using a future satellite, Gaia. The Gaia catalogue plans to include around one billion stars, with an apparent magnitude limit of around 20. Therefore, it will include a sufficient number of stars of our galaxy to assist future projects of modern space science with greater accuracy and wider sample size.
Read more about this topic: Durchmusterung
Famous quotes containing the word modern:
“These modern ingenious sciences and arts do not affect me as those more venerable arts of hunting and fishing, and even of husbandry in its primitive and simple form; as ancient and honorable trades as the sun and moon and winds pursue, coeval with the faculties of man, and invented when these were invented. We do not know their John Gutenberg, or Richard Arkwright, though the poets would fain make them to have been gradually learned and taught.”
—Henry David Thoreau (1817–1862)