The following outline is provided as an overview of and topical guide to astrophysics.

Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are", which is studied in celestial mechanics.

Astrophysics can be described as all of the following:

• An academic discipline: one with academic departments, curricula and degrees; national and international societies; and specialized journals.
• A scientific field (a branch of science) – widely recognized category of specialized expertise within science, and typically embodies its own terminology and nomenclature. Such a field will usually be represented by one or more scientific journals, where peer-reviewed research is published.
  • A natural science – one that seeks to elucidate the rules that govern the natural world using empirical and scientific methods.
    • A branch or field of space science – scientific discipline that involves space exploration and study natural phenomena and physical bodies occurring in outer space, such as space medicine and astrobiology.
      • A branch of astronomy – the study of celestial objects, space, and the universe as a whole.
    • A branch of physics – the fundamental science that studies matter, energy, and their interactions.
• An interdisciplinary field – field of science that overlaps with other sciences.

The subdisciplines of theoretical astrophysics are:

• Astrobiology – studies the advent and evolution of biological systems in the universe.
• Compact objects – this subdiscipline studies very dense matter in white dwarfs and neutron stars and their effects on environments including accretion.
• Computational astrophysics – uses numerical simulations to solve complex astrophysical problems.
• Exoplanet studies – various planets outside of the Solar System.
• Physical cosmology – origin and evolution of the universe as a whole. The study of cosmology is theoretical astrophysics at its largest scale.
• Galactic astronomy – deals with the structure and components of our galaxy and other galaxies.
• High energy astrophysics – studies phenomena occurring at high energies including active galactic nuclei, supernovae, gamma-ray bursts, quasars, and shocks.
• Interstellar astrophysics – study of the interstellar medium, intergalactic medium, and dust.
• Extragalactic astronomy – study of objects (mainly galaxies) outside our galaxy, including Galaxy formation and evolution.
• Stellar astronomy – concerned with star formation, physical properties, life span, variability, stellar evolution, and extinction.
• Plasma astrophysics – studies properties of plasma in outer space.
• Relativistic astrophysics – studies effects of special relativity and general relativity in astrophysical contexts including gravitational waves, gravitational lensing, and black holes.

• History of astrophysics
• Timeline of gravitational physics and relativity
• History of stellar classification

• Astronomical spectroscopy – study of astronomy using spectroscopy to measure the spectrum of electromagnetic radiation emitted by celestial objects.
• Astroparticle physics – studies particles from space and their interactions with matter.
• Black hole – region in space where the gravitational pull is so strong that nothing can escape from it.
• Cosmic ray – high-energy radiation from outer space that may consist of protons or atomic nuclei.
• Doppler effect – change in frequency or wavelength of a wave in relation to an observer moving relative to the wave source.
• Gravitational lensing – bending of light from a distant object due to the gravitational field of a massive object between it and the observer.
• Nucleosynthesis – process by which elements are formed through nuclear reactions in stars.
• Plasma physics – study of charged particles and fluids interacting with self-consistent electric and magnetic fields.
• Polarization – property of waves that describes the orientation of their oscillations.
• Quark matter – hypothetical phase of matter consisting primarily of quarks.
• Interstellar medium – matter that exists in the space between stars in a galaxy.
• Standard candles – astronomical objects with known luminosity used to measure distances in astronomy.
• Stellar evolution – process by which a star changes over time.
• Universe – all existing matter, energy, planets, stars, galaxies, and even the empty space between them.

• Astrophysics Research Institute
• Jodrell Bank Centre for Astrophysics
• Max Planck Institute for Astrophysics

• Annual Review of Astronomy and Astrophysics
• Astronomy and Astrophysics
• Astrophysics and Space Science
• Research in Astronomy and Astrophysics

• Dannie Heineman Prize for Astrophysics

• Carl Sagan^[1]

• Angioletta Coradini
• Gustav Eberhard
• J. Marvin Herndon
• Ofer Lahav
• Donald Howard Menzel
• Carl Pennypacker

• Outline of astronomy

• International Journal of Modern Physics D from World Scientific
• Cosmic Journey: A History of Scientific Cosmology from the American Institute of Physics
• Prof. Sir Harry Kroto, NL, Astrophysical Chemistry Lecture Series. 8 Freeview Lectures provided by the Vega Science Trust.
• Stanford Linear Accelerator Center
• Institute for Space Astrophysics and Cosmic Physics
• Astrophysical Journal
• Astronomy and Astrophysics
• List and directory of peer-reviewed Astronomy / Astrophysics Journals
• Master of Science in Astronomy and Astrophysics
• Ned Wright's Cosmology Tutorial, UCLA
• UNLV Astronomy & Astrophysics department

Astrophysics