International Astronomy and Astrophysics Research Journal

A New Compact Star—the "Triaxial Star"—and the Detection of a Cosmic Baby: A Possibility

Ramen Kumar Parui *

ARC, Room No-F101, Block-F, Mall Enclave, 13, K. B. Sarani, Kolkata- 700 080, India.

*Author to whom correspondence should be addressed.

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Abstract

The “Triaxial Star” was first proposed by S. Chandrasekhar in 1969, but to date it has not detected. The Cosmic Baby, i.e., SwiftJ1818.0-1607, is the youngest magnetar. It’s characteristic age is ~300 years, with a superfast spin period ~ 1.36s and a strong surface dipole magnetic field ~ 3 x 10¹⁴ G. Taking into account three facts:

1. The ambipolar diffusion in the neutron star core is expected to be the dominant mode of field decay in the early evolution of magnetar ( as long as the age much less than ~ 10⁴) ;
2. Magnetars’s field decay is negligible as long as the core temperature is a few times of 10⁸ K (i.e. < 10⁹ K) ;

• • The coupling between the decay of internal magnetic field and the cooling is so strong in the early phase of Magnetar that it significantly slows down both processes but interior magnetic fields able to remain strong enough resulting the core temperature stays higher than several times 10⁸K for thousands years (at least 10³ years proposed by Dall’Osso et al. [1]) we suggest the swift J1818.0-1607 is a triaxial magnetar i.e., simply Triaxial Star. Significance of our study is — continuous observation thus provides an opportunity for (a) detection of existence of a real Triaxial Star, (b) understanding of the evolution from strong to ultra-strong magnetic field of a neutron star and a magnetar , (c) the bizarre properties of newly baby magnetar,d)how the fast spin period and interior ultra-strong magnetic field turn the baby magnetar into a unique compact object possessing spontaneously broken axial symmetry and a potential source for measuring the properties of triaxially deformed neutron star (i.e. Magnetar) or triaxialstar. This author encourages the GW community to search the Triaxial Stars through electromagnetic counterparts during their observation of compact objects.

Keywords: Gravitational waves, triaxial star, neutron star, pulsar, magnetar

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