From Wikipedia, the free encyclopedia
Mauna Kea in
Hawaii is one of the world's premier observatory sites. Pictured is the
W. M. Keck Observatory , an optical
interferometer .
The following
outline is provided as an overview of and topical guide to astronomy:
Astronomy – studies the
universe beyond Earth, including its
formation and development , and the evolution,
physics ,
chemistry ,
meteorology , and
motion of
celestial objects (such as
galaxies ,
planets , etc.) and
phenomena that originate outside the
atmosphere of Earth (such as the
cosmic background radiation ). Astronomy also intersects with biology, as
astrobiology , studying potential life throughout the universe.
Nature of astronomy
Astronomy can be described as all 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 it
A
hobby or part-time pursuit for the satisfaction of personal
curiosity or appreciation of
beauty , the latter especially including
astrophotography .
Branches of astronomy
Astrobiology – studies the advent and
evolution of
biological systems in the universe.
Astrophysics – branch of
astronomy that deals with the
physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior.
[1]
[2] Among the objects studied are galaxies,
stars , planets,
exoplanets , the
interstellar medium and the
cosmic microwave background ; and the properties examined include
luminosity ,
density ,
temperature , and
chemical composition. The subdisciplines of theoretical astrophysics are:
Compact objects – this subdiscipline studies very dense matter in
white dwarfs and
neutron stars and their effects on environments including
accretion .
Physical cosmology – origin and evolution of the universe as a whole. The study of cosmology is theoretical astrophysics at its largest scale.
Quantum cosmology - the study of cosmology through the use of
quantum field theory to explain phenomena
general relativity cannot due to limitations in its framework.
Computational astrophysics – The study of astrophysics using computational methods and tools to develop computational models.
Galactic astronomy – deals with the structure and components of our Galaxy and of 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,
main sequence 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 .
Solar physics – Sun and its interaction with the remainder of the Solar System and interstellar space.
Planetary Science – study of planets, moons, and planetary systems.
Astronomy divided by general technique used for astronomical research:
Astrometry – study of the position of objects in the sky and their changes of position. Defines the system of coordinates used and the
kinematics of objects in our Galaxy.
Observational astronomy – practice of observing celestial objects by using telescopes and other astronomical apparatus. It is concerned with recording data. The subdisciplines of
observational astronomy are generally made by the specifications of the detectors:
Photometry – study of how bright celestial objects are when passed through different filters
Spectroscopy – study of the spectra of astronomical objects
Other disciplines that may be considered part of astronomy:
History of astronomy
Basic astronomical phenomena
Astronomical objects
Astronomical object
Solar System
Sun
Planets
Small Solar System bodies
Exoplanets
Exoplanet (also known as extrasolar planets) – planet outside the Solar System. A total of 4,341 such planets have been identified as of 28 Jan 2021.
Super-Earth – exoplanet with a mass higher than Earth's, but substantially below those of the Solar System's
ice giants .
Mini-Neptune – also known as a gas dwarf or transitional planet. A planet up to 10 Earth masses, but less massive than Uranus and Neptune.
Super-Jupiter – an exoplanet more massive than
Jupiter .
Sub-Earth – an exoplanet "substantially less massive" than Earth and
Venus .
Circumbinary planet – an exoplanet that orbits two stars.
Hot Jupiter – an exoplanet whose characteristics are similar to Jupiter, but that have high surface temperatures because they orbit very close to their parent stars, whereas Jupiter orbits its parent star (the
Sun ) at 5.2 AU (780×106 km), causing low surface temperatures.
Hot Neptune – an exoplanet in an orbit close to its star (normally less than one astronomical unit away), with a mass similar to that of Uranus or Neptune.
Pulsar planet – a planet that orbits a pulsar or a rapidly rotating neutron star.
Rogue planet (also known as an interstellar planet) – a planetary-mass object that orbits the galaxy directly.
Stars and stellar objects
Stars
Variable stars
Supernovae
Supernova
Classes
Related
Structure
Progenitors
Remnants
Discovery
Notable
Research
Black holes
Artist's representation of a black hole.
Black hole
Types
Size
Formation
Properties
Models
Issues
Metrics
Related
Constellations
The 88 modern constellations
Constellation history
The 48 constellations listed by
Ptolemy after 150 AD
The 41 additional constellations added in the 16th and 17th centuries
Obsolete constellations including Ptolemy's Argo Navis
Clusters and nebulae
Bound Unbound Visual grouping
Galaxies
Cosmology
Space exploration
See:
Outline of space exploration
Organizations
Public sector space agencies
Space agencies
Africa
North Africa
Sub-Saharan
North America
South America
Asia
East Asia
Southeast Asia
South Asia
Southwest Asia
Central Asia
Europe
Oceania
World
1 Preceded by the
Soviet space program
Books and publications
Astronomers
See also
References
External links