Coalescence of Strange-Quark Planets with Strange Stars: a New Kind of Sources for Gravitational Wave Bursts

TL;DR

This paper proposes that strange planets spiraling into strange stars could produce detectable gravitational wave bursts, offering a new way to test the strange quark matter hypothesis and explore compact objects.

Contribution

It introduces the concept that strange planets can generate gravitational waves during coalescence with strange stars, providing a novel observational signature for SQM objects.

Findings

Strange planets can spiral close to strange stars without disruption.

Such inspirals can produce detectable gravitational wave bursts.

Upcoming detectors like LIGO and Einstein Telescope can observe these events.

Abstract

Strange quark matter (SQM) may be the true ground state of hadronic matter, indicating that the observed pulsars may actually be strange stars, but not neutron stars. According to this SQM hypothesis, the existence of a hydrostatically stable sequence of strange quark matter stars has been predicted, ranging from 1 --- 2 solar mass strange stars, to smaller strange dwarfs and even strange planets. While gravitational wave (GW) astronomy is expected to open a new window to the universe, it will shed light on the searching for SQM stars. Here we show that due to their extreme compactness, strange planets can spiral very close to their host strange stars, without being tidally disrupted. Like inspiraling neutron stars or black holes, these systems would serve as a new kind of sources for GW bursts, producing strong gravitational waves at the final stage. The events occurring in our local Universe can be detected by the upcoming gravitational wave detectors, such as Advanced LIGO and the Einstein Telescope. This effect provides a unique probe to SQM objects and is hopefully a powerful tool for testing the SQM hypothesis.