Pickering series

The Pickering series is one in 1896, discovered by the American astronomer Edward Charles Pickering spectral series of singly ionized helium ( He ) in the light of the star ζ Puppis - ( Zeta Puppis, Naos ).

Description and explanation

In the Pickering series every other line corresponds approximately to the Balmer series for hydrogen. The additional wavelengths can be approximated well using the equation of Balmer, if in addition to the natural numbers using half values ​​. Pickering therefore initially suspected a particular state of hydrogen, but this could not be confirmed. Niels Bohr found out that the series corresponds to the wavelength of the emission spectrum of He.

Assuming the now obsolete Bohr's atomic model, then can be explained by the Kernmitbewegung why every other line of the Pickering series do not exactly coincide with the Balmer series: the core and the electron orbiting around the common center of mass, resulting in a slight change the Rydberg constant R ∞ yields.

Formula

Wavelengths and numbers

The wave numbers or wavelengths of the Pickering series can be calculated with the following formula:

In which

• Rydberg constant, and
• With, so by the parentheses, always > 0

Considering the Kernmitbewegung, then the formula changes slightly:

With

• The electron mass
• The mass of the helium core.

Energy of the photons

The energy of a photon can be calculated by where the speed of light in vacuum and Planck's constant is.

For the Pickering series, this results in:

In the formula is a Rydberg energy and the ionization of hydrogen.