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While the zero point is defined to be that of Vega for passband filters, there is no defined zero point for bolometric magnitude, and traditionally, the calibrating star has been the sun. [6] However, the IAU has recently defined the absolute bolometric magnitude and apparent bolometric magnitude zero points to be 3.0128×10 28 W and 2.51802× ...
The monochromatic AB magnitude is defined as the logarithm of a spectral flux density with the usual scaling of astronomical magnitudes and a zero-point of about 3 631 janskys (symbol Jy), [1] where 1 Jy = 10 −26 W Hz −1 m −2 = 10 −23 erg s −1 Hz −1 cm −2 ("about" because the true definition of the zero point is based on magnitudes as shown below).
Therefore, the magnitude m, in the spectral band x, would be given by = (,), which is more commonly expressed in terms of common (base-10) logarithms as = (,), where F x is the observed irradiance using spectral filter x, and F x,0 is the reference flux (zero-point) for that photometric filter.
The force of one magnetic dipole on another is determined by using the magnetic field of the first dipole given above and determining the force due to the magnetic field on the second dipole using the force equation given above. Using vector notation, the force of a magnetic dipole m 1 on the magnetic dipole m 2 is: (,,) = [() + + () ()] where ...
Continuous charge distribution. The volume charge density ρ is the amount of charge per unit volume (cube), surface charge density σ is amount per unit surface area (circle) with outward unit normal n̂, d is the dipole moment between two point charges, the volume density of these is the polarization density P.
For objects within the immediate neighborhood of the Sun, the absolute magnitude M and apparent magnitude m from any distance d (in parsecs, with 1 pc = 3.2616 light-years) are related by = = (), where F is the radiant flux measured at distance d (in parsecs), F 10 the radiant flux measured at distance 10 pc.
If the magnetic field is constant, the magnetic flux passing through a surface of vector area S is = = , where B is the magnitude of the magnetic field (the magnetic flux density) having the unit of Wb/m 2 , S is the area of the surface, and θ is the angle between the magnetic field lines and the normal (perpendicular) to S.
Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications in physics. For transport phenomena, flux is a vector quantity, describing the magnitude and direction of the flow of a substance or ...