A nebula (plural: nebulae) is a vast cloud of gas and dust in space. Nebulae can be the birthplaces of stars, regions where new stars are formed, or remnants of dead or dying stars. They come in various forms and types, each with distinct characteristics: 1. **Emission Nebulae**: These are clouds of ionized gas that emit light of their own.
Astronomical catalogues of nebulae are systematic compilations of objects in the night sky that are classified as nebulae, which are vast clouds of gas and dust in space. Historically, these catalogues were essential for astronomers seeking to organize, identify, and study various nebulae and other deep-sky objects, including galaxies, star clusters, and more.
Dark nebulae are a type of interstellar cloud that is dense enough to obscure the light from objects behind them, such as stars and other celestial bodies. Unlike diffuse nebulae, which are composed of gas and dust and can often emit their own light (typically due to excited hydrogen gas), dark nebulae primarily absorb light, creating visually dark patches against the backdrop of brighter stars or regions of space.
Diffuse nebulae are large clouds of gas and dust in space that are not concentrated enough to form distinct shapes like more structured nebulae, such as planetary nebulae or supernova remnants. They are typically characterized by a mixture of hydrogen, helium, and other ionized gases, and they often play a crucial role in the star formation process.
Emission nebulae are a type of astronomical object consisting of ionized gas that emits light at various wavelengths, primarily in the visible spectrum. These nebulae are often found in regions of star formation and are typically associated with young, hot stars that emit high-energy ultraviolet radiation. This radiation ionizes the surrounding gas, causing it to glow and emit light.
Fiction about nebulae often explores themes of the cosmos, the unknown, and the relationship between humanity and the universe. Nebulae, which are vast clouds of gas and dust in space, serve as a backdrop for many imaginative narratives, often embodying mystery and the potential for new worlds and life forms. Here are a few common approaches: 1. **Exploration and Discovery**: Stories may revolve around space travelers or astronauts who venture into nebulae, seeking to unlock their secrets.
H II regions are areas of ionized hydrogen in space, typically found in star-forming regions of galaxies. The designation "H II" refers specifically to atomic hydrogen (H) that has been ionized, meaning its electrons have been stripped away, resulting in positively charged hydrogen ions (H⁺). These regions are often associated with young, hot stars, particularly O and B type stars, which emit large amounts of ultraviolet (UV) radiation.
H I regions, also known as neutral hydrogen regions, are areas in space where hydrogen atoms exist in their neutral state (not ionized). These regions are predominantly composed of hydrogen gas and are crucial for various astrophysical processes.
Herbig-Haro (HH) objects are small, bright patches of nebulosity associated with star-forming regions. They are created by the interaction of stellar jets ejected from young, newly formed stars with the surrounding interstellar medium. The jets typically have high velocities and can collide with the gas and dust surrounding the forming star, causing these bright knots of emission. Herbig-Haro objects were first identified by astronomers George Herbig and Guillermo Haro in the 1940s.
Images of nebulae are photographs or digital representations of nebulae, which are vast clouds of gas and dust in space. These celestial objects are often the birthplace of stars (like stellar nurseries) or the remnants of dead or dying stars. Nebulae can vary greatly in size, shape, and color, depending on their composition and the type of light they emit or reflect.
A list of nebulae typically refers to a compilation of nebulae, which are vast clouds of gas and dust in space, often serving as regions of star formation or remnants of dead stars. Nebulae can be categorized into several types, including: 1. **Emission Nebulae**: These nebulae emit their own light due to ionization of the gas by nearby hot stars. An example is the Orion Nebula (M42).
Lyman-alpha blobs (LABs) are large, luminous regions of hydrogen gas that emit Lyman-alpha radiation, which is a specific wavelength of ultraviolet light produced when electrons in hydrogen atoms transition between energy levels. These blobs are typically found in the early universe and are often associated with star formation and active galactic nuclei (AGNs).
"Nebula stubs" could refer to a few different concepts depending on the context, as "Nebula" can denote various things in tech, entertainment, or even astronomy. However, without additional specifics, I'm assuming you could be referring to one of the following: 1. **Cloud Computing (Nebula)**: Nebula is a cloud computing platform developed by NASA that allows users to create and manage cloud services.
Nova remnants refer to the remnants of a nova explosion, which is an astronomical event characterized by a sudden increase in brightness of a star. This phenomenon typically occurs in a binary star system where one star is a white dwarf and the other is a companion star, often a main-sequence star or a red giant. In a nova event, material from the companion star is accreted onto the surface of the white dwarf.
A planetary nebula is a type of astronomical object formed from the outer layers of a dying star, specifically a star similar in size to our Sun that has exhausted the nuclear fuel in its core. When such a star begins to end its life, it undergoes a series of changes: 1. **Red Giant Phase**: The star expands into a red giant, causing it to shed its outer layers into space.
Post-stellar nebulae are a type of astronomical object that forms when a star has reached the end of its life cycle, specifically after it has exhausted its nuclear fuel and shed its outer layers. This process results in the formation of a nebula filled with gas and dust.
Pre-stellar nebulae are regions in space where the process of star formation is beginning to take shape, but no stars have yet formed. These nebulae are primarily composed of gas and dust and represent the initial stage of the lifecycle of a star. Typically found within larger molecular clouds, pre-stellar nebulae consist of dense cores where material is accumulating.
Pulsar wind nebulae (PWNe) are highly energetic and dynamic structures that form around pulsars, which are rapidly rotating neutron stars emitting beams of radiation, including X-rays and gamma rays. When a pulsar is born from the supernova explosion of a massive star, it can generate a significant outflow of charged particles, known as the pulsar wind. This wind consists mainly of electrons and positrons, and it moves outward at nearly the speed of light.
Reflection nebulae are a type of astronomical object composed of dust and gas that reflects light from nearby stars. Unlike emission nebulae, which glow by ionizing gas through the energy from nearby hot stars, reflection nebulae do not produce their own light. Instead, they scatter the light from nearby stars, causing them to appear illuminated.
"Superbubbles" typically refers to extremely large economic bubbles, often involving asset prices that have inflated significantly beyond their intrinsic value, usually in a speculative frenzy. The term can apply to various asset classes, such as stocks, real estate, or cryptocurrency. These bubbles are characterized by rapid price increases, driven by investor enthusiasm and speculation, often leading to unsustainable market conditions.
Wolf-Rayet nebulae are a type of astronomical object associated with Wolf-Rayet stars, which are massive stars in a late stage of stellar evolution. These stars are characterized by their strong stellar winds, high temperatures, and distinct spectral lines, particularly of heavy elements such as carbon, nitrogen, and oxygen. When a Wolf-Rayet star evolves and sheds a significant portion of its outer layers through powerful stellar winds, it creates an expansive nebula composed of gas and dust.
Barnard 30, also known as LBN 762, is a dark nebula located in the constellation of Cassiopeia. It is a region where dust and gas partially obscure the background stars, creating a dark patch against the brightness of the Milky Way. Barnard 30 is a part of a larger molecular cloud complex, which is often associated with regions of star formation.
Barnard 5 (B5) is a dark nebula located in the constellation Ophiuchus. It is part of the Barnard catalog, a collection of dark nebulae compiled by astronomer Edward Emerson Barnard in the early 20th century. Dark nebulae like Barnard 5 are regions of space that contain a high concentration of dust and gas, which makes them appear opaque against the backdrop of bright stars and other celestial objects.
The term "bipolar nebula" refers to a type of astronomical nebula characterized by a bipolar structure, meaning it has two lobes or outflows that extend in opposite directions. These nebulae are often associated with the late stages of stellar evolution, particularly with certain types of stars, such as preplanetary nebulae and planetary nebulae. Bipolar nebulae are typically formed when a star undergoes significant changes as it exhausts its nuclear fuel.
A circumstellar disc, also known as a protoplanetary disc or accretion disc, is a disc-shaped structure of gas, dust, and other materials that orbits around a star. These discs are commonly found in various stages of stellar evolution, particularly during the formation of stars and planetary systems. **Key characteristics of circumstellar discs include:** 1. **Formation**: Circumstellar discs form from the gas and dust that remains after a star forms from a molecular cloud.
A dark nebula is a type of interstellar dust cloud that is dense enough to obscure the light from stars and other astronomical objects behind it. These nebulae are often composed of gas and dust, and they appear as dark patches against the backdrop of brighter stars or regions of space. Dark nebulae are significant in the study of star formation because they are often the sites where new stars begin to form.
An emission nebula is a type of interstellar cloud of gas and dust that emits light due to the ionization of its hydrogen atoms. This ionization typically occurs when high-energy ultraviolet radiation from nearby hot stars excites the gas, causing it to emit light at various wavelengths, primarily in the red part of the spectrum from hydrogen-alpha emissions. Emission nebulae are often found in regions of active star formation and can be sites where new stars are being born.
An Evaporating Gaseous Globule (EGG) is a type of astronomical structure that is formed in the early stages of star formation, particularly in regions of interstellar space where nascent stars are surrounded by gas and dust. EGGs are thought to consist of dense clumps of gas that are primarily composed of molecular hydrogen and dust particles. They can be relatively small and are typically located in star-forming regions known as molecular clouds.
HD 101584 is a star located in the constellation of Centaurus, approximately 1,140 light-years away from Earth. It is classified as a post-AGB (Asymptotic Giant Branch) star, which indicates that it is in a late stage of stellar evolution. In this phase, a star has exhausted the hydrogen in its core and has moved beyond the red giant phase, potentially leading towards becoming a white dwarf.
HD 87643 is a star located in the constellation of Centaurus, approximately 330 light-years away from Earth. It is classified as a B-type main-sequence star, which means it is a hot, luminous star with a surface temperature significantly higher than that of the Sun. Specifically, its spectral type is B5V, indicating that it has a strong blue hue and emits a large amount of ultraviolet radiation.
An H II region is a large cloud of gas and dust in space that is ionized by the radiation from young, hot stars. The term "H II" refers to the presence of hydrogen ions (protons) in the region.
An H II region is a cloud of ionized hydrogen in interstellar space, which is typically associated with star formation. The term "H II" signifies that the hydrogen in these regions has been ionized, which means that the hydrogen atoms have lost their electrons due to the high-energy ultraviolet radiation emitted by nearby hot, young stars. H II regions are often found surrounding young, massive stars, where the intense radiation and stellar winds from these stars ionize the surrounding hydrogen gas.
High-velocity clouds (HVCs) are a type of interstellar cloud that moves at significant speeds relative to the Milky Way galaxy. These clouds are typically composed of hydrogen, and they are characterized by their high radial velocities, which can be much greater than the average motion of gas in the galaxy.
Integrated Flux Nebula (IFN) refers to a type of diffuse interstellar matter that is found in the Milky Way galaxy. Unlike typical nebulae, which may consist of concentrated clouds of gas and dust, the Integrated Flux Nebula is composed of more diffuse, low-density material that scatters starlight, making it faintly visible against the background of the night sky. IFN is typically associated with the light from nearby stars, particularly those that are part of our galaxy.
An interstellar cloud, also known as a molecular cloud, is a dense region of gas and dust located in the space between stars within a galaxy. These clouds play a crucial role in the formation of stars and planets. Interstellar clouds primarily consist of hydrogen molecules, with smaller amounts of helium and other elements. They can vary in density and temperature, with some being cold and dense enough to foster the formation of new stars and planetary systems.
NGC 2078 is a star cluster located in the Large Magellanic Cloud (LMC), which is a satellite galaxy of the Milky Way. This open cluster is situated in the constellation Dorado and is part of the rich star-forming region of the LMC. NGC 2078 is notable for its stars, many of which are relatively young, and it has been studied for insights into stellar evolution and the dynamics of star clusters.
NGC 6326 is a planetary nebula located in the constellation of Ara. It is known for its complex structure and bright appearance, which is typical of many planetary nebulae. NGC 6326 is a region of ionized gas that has been expelled from a dying star, which in this case is a post-main-sequence star that has shed its outer layers.
Nebulium is an outdated term that was historically used to refer to a hypothetical element believed to exist in the nebulae, particularly in the context of early astrophysical studies. The concept emerged in the late 19th century when scientists were trying to understand the spectral lines observed in certain nebular emissions, especially those that did not correlate with known elements at the time.
A pulsar wind nebula (PWN) is a type of astronomical nebula formed by the wind of particles emitted from a rotating neutron star, known as a pulsar. Pulsars are highly magnetized, rotating neutron stars that emit beams of electromagnetic radiation out of their magnetic poles. As the pulsar rotates, these beams sweep across space, and when they are pointed towards Earth, they are detected as pulses of radiation, hence the name "pulsar.
A reflection nebula is a type of nebula that does not emit its own light but instead reflects the light of nearby stars. These nebulae are often composed of dust and gas, which scatter the light from nearby luminous stars, making them visible. Reflection nebulae tend to appear blue because blue light is scattered more effectively than red light by the small particles in the dust.
Sh2-308, also known as the "Dragon Nebula," is an emission nebula located in the constellation Monoceros, the Unicorn. It is part of a larger region of star formation and is noted for being a site of active stellar birth. Sh2-308 is associated with the open star cluster NGC 2244, which is a young cluster of stars that has formed from the surrounding gas and dust.
A supernova remnant is the structure resulting from the explosion of a star in a supernova event. When a massive star exhausts its nuclear fuel, it undergoes gravitational collapse followed by a catastrophic explosion, ejecting the outer layers of the star into space at high velocities. This explosion not only disperses a vast amount of stellar material, but it also generates intense shock waves that propagate through the surrounding interstellar medium.
A variable nebula is a type of astronomical object that exhibits changes in brightness or appearance over time due to various factors, including the motion of material within the nebula or changes in the illumination by nearby stars. These nebulas are often associated with young stars and can be composed of gas and dust.
A Wolf-Rayet nebula is a type of nebula associated with Wolf-Rayet stars, which are hot, massive stars in a late stage of stellar evolution. These stars are characterized by strong stellar winds and high temperatures, leading to significant mass loss. The material expelled from these stars interacts with the surrounding interstellar medium, creating distinctive nebulous structures. Wolf-Rayet nebulae are often observed in the context of massive star-forming regions or the remnants of supernova explosions.
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