Star Formation (SF), the process by which stars are born, is thought to be understood in outline, but questions remain, perhaps more than for models of subsequent stellar evolution. Clouds sufficiently dense will gravitationally collapse, but an interesting question is when and how this density arises.
Molecular Clouds and interstellar Dust apparently sometimes develop dense patches that collapse into stars. Areas of such activity are known as stellar nurseries or Star-Forming Regions. Triggering events include collisions of clouds, nearby supernovae, or the collision of galaxies. Accretion of Cold Gas from the Intergalactic Medium increases the probability of star formation and can trigger it as well. Nearby dust will be heated, producing a lower-Temperature blackbody.spectrum, with longer Wavelength Electromagnetic Radiation such as Radio. As a general rule regarding galaxies, the more Infrared it emits (a sign of heated dust), the higher the Star Formation Rate.
The term Quenching is used to indicate the cessation of star formation, e.g., in a galaxy, which would be said to become Quiescent. For the long term, a star forming region is assumed to cease due to gas heating from hot stars and supernovae (Star Formation Feedback), followed by cooling and settling and perhaps triggers from nearby events. Thus a long-term Star Formation Rate must be time-averaged over periods of high and low star formation.
The term Star and Planet Formation (SPF) covers Star Formation and Planet Formation as well, which is believed to happen during the first few million years of a star's life.
Active Galactic Nucleus (AGN)
Balmer-Break Galaxy (BBG)
Cosmic Gamma Ray Background (CGB)
Canadian Institute for Theoretical Astrophysics (CITA)
Star Formation Feedback
Galaxy Main Sequence
Galaxy Evolution Explorer (GALEX)
Gas Fraction Estimation
Giant Molecular Cloud (GMC)
Habitable Zone (HZ)
HII Region (HII)
Institute of Theoretical Astrophysics (ITA)
Lyman-Alpha Emitter (LAE)
Lynds Catalog of Dark Nebulae (LDN)
Luminous Infrared Galaxy (LIRG)
Molecular Cloud Turbulence
Molecular Deep Field
Peak Star-Formation Epoch
Spectral Energy Distribution (SED)
Star Formation History (SFH)
Star Formation Rate (SFR)
Star-Forming Region (SFR)
Star-Formation Rate Stellar-Mass Ratio
Submillimeter Galaxy (SMG)
Tomographic Ionized-Carbon Mapping Experiment (TIME)
Toomre Q Parameter (Q)