Glossary term: Star Formation
Description: The birth of a star results from gravitational collapse of cold and dense regions called cores within giant molecular clouds, which are mostly found in the spiral arms of galaxies. Star formation involves complex physical processes, occurring at different scales, resulting from the effects of gravity, pressure, radiation, magnetic fields, turbulence, chemistry, etc., some of which are still not well understood. Depending on the mass of the parent cloud and accretion processes during the formation stages, the mass of the star can range from 0.08 to a few hundred solar masses. Most stars do not form in isolation but as part of a cluster of stars. During the formation stages, a protostellar disk builds up around the central star, which eventually provides the building material for planets to form.
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Term and definition status: This term and its definition have been approved by a research astronomer and a teacher
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".
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In Other Languages
- Arabic: تشكّل النجوم
- German: Sternentstehung
- French: Formation des étoiles
- Italian: Formazione delle stelle
- Japanese: 星形成 (external link)
- Simplified Chinese: 恒星形成
- Traditional Chinese: 恆星形成
Related Media
Witnessing the birth of a star
Caption: A combination of radio and visible light imaged with the Atacama Large Millimeter/submillimeter Array (ALMA) and European Southern Observatory's New Technology Telescope (NTT) revealing birth of a star forming the Herbig-Haro object HH 46/47. ALMA observations shown in orange and green unveil the energetic jet from the central protostar otherwise hidden at visible wavelength due to dust obscuration and dense gas. NTT observations in pink and purple highlight the visible light from the jet emitted towards the observer.
Credit: ESO/ALMA (ESO/NAOJ/NRAO)/H. Arce. Acknowledgements: Bo Reipurth
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License: CC-BY-3.0 Creative Commons Attribution 3.0 Unported icons
Stellar birth environment
Caption: Snapshot of the formation of multiple protostars in the Orion Molecular Clouds with a closer look at each of them with the Atacama Large Millimeter/submillimeter Array and Very Large Array. Such an image provides unique insights of the process and early stages of star formation as well as the influence of the parent cloud in which they form.
Credit: ALMA (ESO/NAOJ/NRAO), J. Tobin; NRAO/AUI/NSF, S. Dagnello; Herschel/ESA
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License: CC-BY-3.0 Creative Commons Attribution 3.0 Unported icons
The Pillars of Creation in comparison
Caption: The 'Pillars of Creation' are a renowned astronomical feature situated within the Eagle Nebula in the Serpens constellation. The illustration provides a direct comparison between images captured by the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST), showcasing the pillars, which span several light years in diameter, in both visible light (also known as optical light) and infrared light. On the left are the pillars as seen by Hubble in visual light, taken in 2014. It displays dark pillars against an opaque background, with only a handful of visible stars. Conversely, the counterpart on the right is Webb’s near-infrared view published in 2022, penetrating the dust and revealing numerous stars of varying sizes.
Their distance from Earth is approximately 6,500 to 7,000 light years. Within these pillars, new stars are constantly forming, making them a subject of extensive study by astronomers. Composed mostly of cool molecular hydrogen and small amounts of interstellar dust, they are subject to erosion by the intense ultraviolet radiation emitted by nearby massive and newborn stars, a process known as photoevaporation.
Credit: NASA, ESA, CSA, STScI
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License: CC-BY-2.0 Creative Commons Attribution 2.0 Generic icons
Herschel’s view of new stars and molecular clouds
Caption: This image shows the Westerhout 3, 4 and 5 star formation regions. This area has huge amounts of gas and dust. This gas and dust hides the physical processes going on in this region from studies using visible light. This image was taken in infrared light by the Herschel Space Observatory. This infrared light allowed Herschel to see deep into these star forming regions.
In Westerhout 3, 4 and 5, huge, cold clouds of molecular hydrogen have collapsed into dense knots and filaments. Within these new structures the gas is dense and cold enough for it to collapse and form stars. These new stars give off powerful winds of charged particles, like stronger versions of the solar wind our sun gives off. These winds have combined to blow massive bubbles in the surrounding gas and dust. These are visible as the large darker voids in the image.
Credit: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech)
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License: CC-BY-3.0-IGO Creative Commons Attribution 3.0 IGO icons
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