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:
“Much of the modern resistance to chastity comes from men’s belief that they “own” their bodies—those vast and perilous estates, pulsating with the energy that made the worlds, in which they find themselves without their consent and from which they are ejected at the pleasure of Another!”
—C.S. (Clive Staples)