tähtitilaston

Tähtitilaston is a Finnish term describing a systematic collection and presentation of star statistics and rankings. It encompasses measurements of stars' brightness, position, and visibility, and aims to make astronomical data accessible to both enthusiasts and professionals. The concept emphasizes comparability across celestial objects and sky conditions, enabling quick assessments of which stars are most prominent in a given region or time.

The term emerged from Finnish amateur astronomy circles and educational resources, later integrating digital catalogues and international data releases. Modern tähtitilaston draws on major astrometric and photometric catalogs such as Gaia, Hipparcos, and 2MASS, updated when new data become available. Data are typically standardized with celestial coordinates (right ascension and declination), apparent magnitude, parallax, proper motion, and spectral type, with notes on extinction and observational biases.

Entries or summaries may rank stars by apparent magnitude, by visibility from a specific latitude, or by statistical measures of stellar distribution within constellations or sky sectors. The underlying aims include facilitating sky planning, teaching, and public outreach, as well as providing a reference for researchers studying stellar populations.

Limitations include incomplete coverage for very faint stars, biases due to sky brightness and observational conditions, and uncertainties in measurements. As catalogs are revised, tähtitilaston evolves to reflect improved accuracy and expanded reach.

See also: Gaia mission, Hipparcos catalogue, stellar catalogues, apparent magnitude, celestial coordinates.