bolometric

Bolometric refers to bolometry, a method and concept used to measure the total power or energy of electromagnetic radiation emitted, absorbed, or detected across all wavelengths. The term comes from the bolometer, a detector whose signal arises from the heating effect of incident radiation.

A bolometer is designed to respond to a broad range of wavelengths by absorbing energy and exhibiting a measurable temperature rise or change in electrical resistance. Bolometers are used in various forms, including resistive, superconducting, and microcalorimeter types, and find applications in astronomy, infrared imaging, submillimeter astronomy, and terahertz sensing.

In astronomy, bolometric quantities describe the total energy flux or luminosity of an object integrated over the entire spectrum. The bolometric flux f_bol is the energy per unit area per unit time received from a source across all wavelengths, and the bolometric luminosity L_bol is related by L_bol = 4πd^2 f_bol for a source at distance d. The bolometric magnitude M_bol is a logarithmic measure tied to L_bol. In practice, observers often estimate bolometric quantities by summing multi-band measurements and applying bolometric corrections that account for portions of the spectrum not directly observed.

Bolometric corrections depend on the spectral energy distribution and the filters used, and are affected by interstellar extinction. Accurate bolometric estimates typically rely on stellar atmosphere models or empirical calibrations. Limitations include incomplete wavelength coverage, calibration uncertainties, and extinction, but bolometric concepts provide a standard framework for comparing the total energetics of astronomical sources.