Related Research Articles
A nebula is a distinct luminescent part of interstellar medium,which can consist of ionized,neutral,or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions,such as in the "Pillars of Creation" in the Eagle Nebula. In these regions,the formations of gas,dust,and other materials "clump" together to form denser regions,which attract further matter and eventually become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects.
Star formation is the process by which dense regions within molecular clouds in interstellar space,sometimes referred to as "stellar nurseries" or "star-forming regions",collapse and form stars. As a branch of astronomy,star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process,and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation,another branch of astronomy. Star formation theory,as well as accounting for the formation of a single star,must also account for the statistics of binary stars and the initial mass function. Most stars do not form in isolation but as part of a group of stars referred as star clusters or stellar associations.
The New General Catalogue of Nebulae and Clusters of Stars is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects,including galaxies,star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908,known as the Index Catalogues,describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers,which remain in widespread use.
An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place,with a size ranging from one to hundreds of light years,and density from a few to about a million particles per cubic centimetre. The Orion Nebula,now known to be an H II region,was observed in 1610 by Nicolas-Claude Fabri de Peiresc by telescope,the first such object discovered.
The North America Nebula is an emission nebula in the constellation Cygnus,close to Deneb. It is named because its shape resembles North America.
The Elephant's Trunk Nebula is a concentration of interstellar gas and dust within the much larger ionized gas region IC 1396 located in the constellation Cepheus about 2,400 light years away from Earth. The piece of the nebula shown here is the dark,dense globule IC 1396A;it is commonly called the Elephant's Trunk nebula because of its appearance at visible light wavelengths,where there is a dark patch with a bright,sinuous rim. The bright rim is the surface of the dense cloud that is being illuminated and ionized by a very bright,massive star that is just to the east of IC 1396A. The entire IC 1396 region is ionized by the massive star,except for dense globules that can protect themselves from the star's harsh ultraviolet rays.
The Astronomical Society of the Pacific (ASP) is an American scientific and educational organization,founded in San Francisco on February 7,1889,immediately following the solar eclipse of January 1,1889. Its name derives from its origins on the Pacific Coast,but today it has members all over the country and the world. It has the legal status of a nonprofit organization.
Bartholomeus Jan "Bart" Bok was a Dutch-American astronomer,teacher,and lecturer. He is best known for his work on the structure and evolution of the Milky Way galaxy,and for the discovery of Bok globules,which are small,densely dark clouds of interstellar gas and dust that can be seen silhouetted against brighter backgrounds. Bok suggested that these globules may be in the process of contracting,before forming into stars.
A deep-sky object (DSO) is any astronomical object that is not an individual star or Solar System object. The classification is used for the most part by amateur astronomers to denote visually observed faint naked eye and telescopic objects such as star clusters,nebulae and galaxies. This distinction is practical and technical,implying a variety of instruments and techniques appropriate to observation,and does not distinguish the nature of the object itself.
Herbig–Haro(HH) objects are bright patches of nebulosity associated with newborn stars. They are formed when narrow jets of partially ionised gas ejected by stars collide with nearby clouds of gas and dust at several hundred kilometres per second. Herbig–Haro objects are commonly found in star-forming regions,and several are often seen around a single star,aligned with its rotational axis. Most of them lie within about one parsec of the source,although some have been observed several parsecs away. HH objects are transient phenomena that last around a few tens of thousands of years. They can change visibly over timescales of a few years as they move rapidly away from their parent star into the gas clouds of interstellar space. Hubble Space Telescope observations have revealed the complex evolution of HH objects over the period of a few years,as parts of the nebula fade while others brighten as they collide with the clumpy material of the interstellar medium.
In astronomy,Bok globules are isolated and relatively small dark nebulae containing dense cosmic dust and gas from which star formation may take place. Bok globules are found within H II regions,and typically have a mass of about 2 to 50 solar masses contained within a region about a light year or so across (about 4.5×1047 m3). They contain molecular hydrogen (H2),carbon oxides and helium,and around 1% (by mass) silicate dust. Bok globules most commonly result in the formation of double- or multiple-star systems.
IC 2944,also known as the Running Chicken Nebula,the Lambda Centauri Nebula or the λCentauri Nebula,is an open cluster with an associated emission nebula found in the constellation Centaurus,near the star λCentauri. It features Bok globules,which are frequently a site of active star formation. However,no evidence for star formation has been found in any of the globules in IC 2944. Other designations for IC 2944 include RCW 62,G40 and G42.
L 1157 is a dark nebula in the constellation Cepheus. It was catalogued in 1962 by U.S. astronomer Beverly T. Lynds in her Catalogue of Dark Nebulae,becoming the 1157th entry in the table;hence the designation. The cloud contains an estimated 3,900 Solar masses of material. It includes protostars that are ejecting material in bipolar outflows,forming bow shocks in the surrounding ambient gas. Formamide and HCNO have been detected in these shocked regions,among other compounds.
Leopold Goldberg was an American astronomer who held professorships at Harvard and the University of Michigan and the directorships of several major observatories. He was president of both the International Astronomical Union and the American Astronomical Society. His research focused on solar physics and the application of atomic physics to astronomy,and he led many of the early efforts to study the Sun from space telescopes.
Lynds' Catalogue of Bright Nebulae is an astronomical catalogue of bright nebulae.
Adelaide Ames was an American astronomer and research assistant at Harvard University. She was best known for her work on detailed surveys of the brightest extra-galactic spiral nebulae. She contributed to the study of galaxies with her co-authorship of A Survey of the External Galaxies Brighter Than the Thirteenth Magnitude,which was later known as the Shapley-Ames catalog. Ames was a member of the American Astronomical Society. She was a contemporary of Cecilia Payne-Gaposchkin and her closest friend at the observatory.
The Barnard Catalogue is an astronomical catalogue of dark nebulae.
Silvia Torres-Peimbert is a Mexican astronomer. She won the L'Oréal-UNESCO Awards for Women in Science in 2011 for Latin America for her work determining the chemical composition of nebulae.
Lynds' Catalogue of Dark Nebulae is an astronomical catalogue of dark nebulae.
Lynds' Catalogue may refer to either of the following astronomical catalogues compiled by American astronomer Beverly Turner Lynds:
References
- ↑ Lynds, Beverly T. (1962). "Catalogue of Dark Nebulae" (PDF). The Astrophysical Journal Supplement Series. 7: 1–52. Bibcode:1962ApJS....7....1L. doi:10.1086/190072. ISSN 0067-0049.
- 1 2 3 Petrosian, Vahe; Stockton, Alan; Jr., Earl J. O’Neil; Lynds, Beverly T. (January 22, 2024). "Clarence Roger Lynds (1928-2023)". Bulletin of the American Astronomical Society. 56 (1). American Astronomical Society. Bibcode:2024BAAS...56a.002P. doi: 10.3847/25c2cfeb.cb054d76 .
- ↑ "Elementary Astronomy". Oxford University Press. 1959.
- ↑ Lynds, Beverly T. (1971). Dark Nebulae, Globules, and Protostars. Tucson: University of Arizona Press. ISBN 978-0-8165-0300-1.
- ↑ Reipurth, Bo (2022). "An interview with Beverly Lynds". The Star Formation Newsletter. Retrieved July 15, 2024.
- ↑ "Beverly T. Lynds". International Astronomical Union . Retrieved July 15, 2024.
- ↑ Andrew lynds (April 18, 2023). "Roger Lynds Obituary (2023)". Legacy.com. Retrieved July 15, 2024.
- ↑ Aller, Lawrence H. (July 23, 1997). "Leo Goldberg". Biographical Memoirs: V.72. Washington, D.C.: National Academies Press. pp. 115–134. doi:10.17226/5859. ISBN 978-0-309-05788-2.
| International | |
|---|---|
| National | |
| Academics | |
| People | |
| Other | |
