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:
“O born in days when wits were fresh and clear,
And life ran gaily as the sparkling Thames;
Before this strange disease of modern life,
With its sick hurry, its divided aims,
Its head o’ertaxed, its palsied hearts, was rife—”
—Matthew Arnold (1822–1888)