Convert Kiloparsec (kpc) to Bohr Radius (a₀) instantly.
About these units
Kiloparsec (kpc)
A kiloparsec, equal to 1,000 parsecs, is used to express distances on the scale of large stellar groups, spiral arm structures, and galactic dimensions. The Milky Way, for instance, spans roughly 30 kpc in diameter, and the Sun is located about 8 kpc from the galactic center. Kiloparsecs provide a natural scale for modeling galactic rotation curves, star cluster distributions, and gravitational interactions between galactic features. Using parsecs alone would result in very large numbers, while megaparsecs would be too large for most galactic phenomena. The unit is essential in cosmology and astrophysics, where researchers examine interstellar distances, halo sizes, and the spatial arrangement of star-forming regions. The kpc helps create an intuitive sense of the Milky Way's architecture and the scale of galactic environments.
Bohr Radius (a₀)
The Bohr radius, equal to approximately 5.29177 × 10⁻¹¹ meters, is the most probable distance between the electron and nucleus in the ground state of hydrogen according to the Bohr model. While modern quantum mechanics has evolved far beyond the Bohr model, the radius remains a remarkably accurate approximation for average atomic dimensions. The Bohr radius acts as a natural "yardstick" for the size of atoms and is frequently used in atomic physics and quantum chemistry. Many atomic properties — orbital sizes, electron probability distributions, and energy levels — are conveniently expressed in multiples of the Bohr radius. Because it reflects fundamental constants, including Planck's constant and the electron charge, the Bohr radius also appears in theoretical analyses of physical systems and helps unify atomic physics concepts across different contexts.