Frequency separation is a term used in Helio and Asteroseismology for the spacing in frequency between adjacent modes of oscillation having the same angular degree (l) but different radial order (n).
For a sun-like star the frequency can be further described using the 'large frequency spacing' between modes of different radial order (136 μHz in the sun), and the 'small frequency spacing' between modes of even and odd angular degree within the same radial order (9.0 μHz in the sun). The period corresponding to the large frequency spacing can be shown to be approximately the same as the time required for a sound wave to travel to the centre of the sun and return, confirming the global nature of the oscillations seen.
A further frequency separation, the rotational splitting can be seen in high-resolution solar data between modes of the same angular degree, but different azimuthal order (m). This gives information
| Star | Large Frequency Separation | Small Frequency Separation |
|---|---|---|
| The Sun | 136 μHz | 9.0 μHz |
| Arcturus | 0.825 0.049 μHz | Not Present |
Famous quotes containing the words frequency and/or separation:
“The frequency of personal questions grows in direct proportion to your increasing girth. . . . No one would ask a man such a personally invasive question as “Is your wife having natural childbirth or is she planning to be knocked out?” But someone might ask that of you. No matter how much you wish for privacy, your pregnancy is a public event to which everyone feels invited.”
—Jean Marzollo (20th century)
“Last evening attended Croghan Lodge International Order of Odd Fellows. Election of officers. Chosen Noble Grand. These social organizations have a number of good results. All who attend are educated in self-government. This in a marked way. They bind society together. The well-to-do and the poor should be brought together as much as possible. The separation into classes—castes—is our danger. It is the danger of all civilizations.”
—Rutherford Birchard Hayes (1822–1893)