The mergers of double neutron star (NS–NS) and black hole (BH)–NS binaries are promising gravitational wave (GW) sources for Advanced LIGO and future GW detectors. The neutron-rich ejecta from such merger events undergoes rapid neutron capture (r-process) nucleosynthesis, enriching our Galaxy with rare heavy elements like gold and platinum. The radioactive decay of these unstable nuclei also powers a rapidly evolving, supernova-like transient known as a “kilonova” (also known as “macronova”). Kilonovae are an approximately isotropic electromagnetic counterpart to the GW signal, which also provides a unique and direct probe of an important, if not dominant, r-process site. I review the history and physics of kilonovae, leading to the current paradigm of week-long emission with a spectral peak at near-infrared wavelengths. Using a simple light curve model to illustrate the basic physics, I introduce potentially important variations on this canonical picture, including: \(\sim \)day-long optical (“blue”) emission from lanthanide-free components of the ejecta; \(\sim \)hour-long precursor UV/blue emission, powered by the decay of free neutrons in the outermost ejecta layers; and enhanced emission due to energy input from a long-lived central engine, such as an accreting BH or millisecond magnetar. I assess the prospects of kilonova detection following future GW detections of NS–NS/BH–NS mergers in light of the recent follow-up campaign of the LIGO binary BH–BH mergers.

双中子星 (NS-NS) 和黑洞 (BH)-NS 双星的合并是先进 LIGO 和未来 GW 探测器的有前途的引力波 (GW) 源。此类合并事件产生的富含中子的喷射物经历快速中子俘获（r过程）核合成，使我们的银河系富含金和铂等稀有重元素。这些不稳定原子核的放射性衰变也为快速演化的超新星瞬变提供动力，称为“千新星”（也称为“巨新星”）。千新星是引力波信号的近似各向同性电磁对应物，它还提供了对重要（如果不是主导） r过程位点的独特且直接的探测。我回顾了千新星的历史和物理学，导致了目前在近红外波长处出现光谱峰值的为期一周的发射范例。使用简单的光曲线模型来说明基本物理原理，我介绍了该规范图片的潜在重要变化，包括：\(\sim \)来自喷射物中不含镧系元素的成分的全天光学（“蓝色”）发射；\(\sim \)长达一小时的前体紫外线/蓝色发射，由最外喷射层中自由中子的衰变提供动力；由于来自长寿命中央引擎（例如吸积 BH 或毫秒磁星）的能量输入而导致排放增加。根据最近 LIGO 双星 BH-BH 合并的后续活动，我评估了未来 NS-NS/BH-NS 合并的 GW 探测后千新星探测的前景。