An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 9 Search : Balmer
Balmer
  بالمر   
Bâlmer

Fr.: Balmer   

From Johann Jakob Balmer (1825-1898), Swiss mathematician and physicist, who explained the visible spectral lines of the hydrogen spectrum in 1885.

Balmer continuum
  پیوستار ِ بالمر   
peyvastâr-e Bâlmer

Fr.: continuum de Balmer   

A continuous range of wavelengths in the Balmer spectrum of hydrogen corresponding to transitions between the energy levels n = 2 and n = .

Balmer; → continuum.

Balmer decrement
  کاهه‌ی ِ بالمر   
kâhe-ye Bâlmer

Fr.: décrément de Balmer   

The intensity ratio among the couple of relatively adjacent → Balmer lines, for example Hα/Hβ and Hβ/Hγ, which have well-known theoretical values. They are used to determine the → interstellar extinction.

Balmer; → decrement.

Balmer discontinuity
  ناپیوستگی ِ بالمر   
nâpeyvastegi-ye Bâlmer

Fr.: discontinuité de Balmer   

An abrupt decrease in the intensity of the continuum at the limit of the → Balmer series of hydrogen (at about 3650 Å), caused by the energy absorbed when electrons originally in the second → energy level are ionized. Same as → Balmer jump.

Balmer; → discontinuity.

Balmer formula
  دیسول ِ بالمر   
disul-e Bâlmer

Fr.: formule de Balmer   

A special solution of the mathematical formula which represents the wavelengths of the various spectral series of hydrogen in which the lower energy level is n = 2.

Balmer; → formula.

Balmer jump
  جهش ِ بالمر   
jaheš-e Bâlmer

Fr.: saut de Balmer   

Same as → Balmer discontinuity.

Balmer; → jump.

Balmer limit
  حد ِ بالمر   
hadd-e Bâlmer

Fr.: limite de Balmer   

The wavelength in the blue end of the → Balmer series, at 3646 Å, near which the separation between successive lines decreases and approaches a → continuum.

Balmer; → limit.

Balmer line
  خط ِ بالمر   
xatt-e Bâlmer

Fr.: raies de Balmer   

The → spectral lines making up the → Balmer series.

Balmer; → line.

Balmer series
  سری ِ بالمر   
seri-ye Bâlmer (#)

Fr.: série de Balmer   

A series of hydrogen → spectral lines (Hα, Hβ, Hγ, and others) that lies in the visible portion of the spectrum and results when electrons from upper → energy levels (n > 2) undergo → transition to n = 2.
Historically, Balmer emission lines (mainly Hα) from ionized nebulae were first observed by O. Struve and C. T. Elvey (1938, ApJ 88, 364). This was an important indication of the existence of hydrogen, in the ionized state, in the → interstellar medium.

Balmer; → series.