Quantum Liquid Signatures in Dwarf Stars

TL;DR

This paper proposes that helium-core dwarf stars may contain a charged condensate of spin-0 nuclei, which affects their cooling and luminosity, potentially explaining observed features in star populations.

Contribution

It introduces a theoretical model of a charged condensate in dwarf stars and predicts its impact on stellar evolution and observable properties.

Findings

Dwarf stars with charged condensates cool faster than crystallized stars.

The luminosity function shows a sharp drop-off after condensation.

Potential observational signature in NGC 6397 star cluster.

Abstract

We develop further the proposal of arXiv:0806.3692 that a new state of matter -- charged condensate of spin-0 nuclei -- may exist in helium-core dwarf stars. The charged condensate and its fluctuations are described by an effective field theory Lagrangian. The spectrum of bosonic fluctuations is gapped, while electrons, at temperatures of interest, give rise to gapless excitations near the Fermi surface. These properties determine the evolution of the dwarfs with condensed cores. In particular, we show that such dwarf stars would cool significantly faster than their crystallized counterparts. As a result, the luminosity function for the helium-core dwarfs will have a sharp drop-off after the condensation. It is tempting to interpret the recently discovered abrupt termination of a sequence of 24 helium-core dwarf candidates in NGC 6397 as a signature of the charged condensation.