Magnetic Moments and Angular Momenta in Stars and Planets

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Session 111 -- Stellar Interiors
Display presentation, Saturday, January 15, 9:30-6:45, Salons I/II Room (Crystal Gateway)

[111.01] Magnetic Moments and Angular Momenta in Stars and Planets

N. Arge, D. J. Mullan (Bartol), A. Dolginov (LPI)

Using published data on magnetic fields, radii, masses, and rotation, we have compiled a dataset of magnetic moment $M$ and angular momentum $J$ for stars and planets. The stellar sub-sample extends from spectral class O to class M, with members of all classes represented. Among the hotter stars (classes A, B, and O), the sample includes 134 objects. For the cooler stars (classes F, G, K, and M), there are 33 objects. Our sub-sample of white dwarfs includes 33 objects, some in cataclysmic variables. The neutron star sub-sample contains 17 pulsars in binaries and 86 isolated pulsars. The solar system sub-sample contains seven planets plus the Sun. We find statistically significant positive correlations between log $M$ and log $J$ in the hot sub-sample and in the cool sub-sample: however, the slopes of the correlations are quite different for hot and cool stars. In the solar system sub-sample, the correlation has essentially the same slope as for the cool stars, although the intercept is almost two orders of magnitude smaller for the solar-system objects. For the isolated pulsars, we find no statistically significant correlation, while pulsars in binaries show a significant anti-correlation. Anti-correlation also appears in the white dwarf sub-sample, but this result relies heavily on five systems where rotational information is ambiguous.

\vskip0.2truein \noindent This work has been supported by NASA Grant NAGW-2456.

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