Termo do glossário: Nebulosa Planetária
Descrição: Uma nebulosa planetária é uma nuvem de gás e poeira proveniente das camadas externas de uma estrela em seus estágios finais e que se expande pelo meio interestelar. O gás, energizado pela luz ultravioleta da estrela em fim de vida, brilha com um espectro de linhas de emissão. Algumas nebulosas planetárias são aproximadamente esféricas e podem se assemelhar a um planeta em um pequeno telescópio, mas sua natureza é completamente diferente. Outras nebulosas planetárias não são esféricas, devido à rotação da estrela, ao campo magnético ou à binaridade.
Termos relacionados:
Ver este termo em outros idiomas
Status do termo e da definição: A definição original deste termo em inglês foi aprovada por um astrônomo(a) pesquisador(a) e um(a) professor(a) A tradução deste termo e de sua definição ainda aguarda aprovação
O Glossário Multilíngue da OAE é um projeto do Escritório da IAU de Astronomia para a Educação (OAE) em colaboração com o Escritório da IAU para Divulgação da Astronomia (OAO). Os termos e definições foram selecionados, escritos e revisados por meio de um esforço coletivo da OAE, dos Centros e Nós da OAE, dos Coordenadores Nacionais de Educação em Astronomia (NAECs) da OAE e de outros voluntários. Você pode encontrar uma lista completa dos créditos aqui. Todos os termos do glossário e suas definições são disponibilizados sob uma licença Creative Commons CC BY-4.0 e devem ser creditados à "IAU OAE".
Se você notar algum erro factual ou de tradução neste termo do glossário ou em sua definição, por favor entre em contato.
Em outros idiomas
- Árabe: السديم الكوكبي
- Alemão: Planetarischer Nebel
- Inglês: Planetary Nebula
- Espanhol: Nebulosa planetaria
- Francês: Nébuleuse planétaire
- Hindi: प्लॅनेटरी नेबुला (ग्रह नीहारिका)
- Italiano: Nebulosa planetaria
- Japonês: 惑星状星雲 (link externo)
- Marathi: प्लॅनेटरी नेबुला (तेजोमेघ )
- Chinês Simplificado: 行星状星云
- Chinês Tradicional: 行星狀星雲
Diagramas relacionados
Mapa da Constelação de Andrômeda
Legenda: A constelação de Andrômeda mostrando as estrelas brilhantes e as constelações vizinhas. Andrômeda é cercada por (no sentido horário a partir do topo) Cassiopeia, Lacerta, Pegasus, Peixes, Áries, Triângulo e Perseu. A estrela mais brilhante de Andrômeda (Alpheratz) está na parte inferior da constelação. Juntamente com três estrelas em Pegasus, ela forma o asterismo conhecido como o "Grande Quadrado de Pegasus". As próximas duas estrelas brilhantes da constelação (Mirach e Almach) formam uma linha que se estende a nordeste de Alpheratz.
Andrômeda é uma constelação do norte e é mais visível nas noites de outono do Hemisfério Norte. É visível de todo o hemisfério norte e da maioria das regiões temperadas do hemisfério sul, mas não é visível das regiões antárticas e subantárticas.
O objeto mais famoso de Andrômeda, a Galáxia de Andrômeda, está marcado aqui com uma elipse vermelha e seu número de catálogo Messier M31.
O círculo amarelo à esquerda marca a posição do aglomerado aberto NGC 752 e o círculo verde à direita marca a NGC 7662 (a nebulosa bola de neve azul), uma nebulosa planetária.
O eixo y desse diagrama está em graus de declinação, com o norte para cima, e o eixo x está em horas de ascensão reta, com o leste à esquerda. Os tamanhos das estrelas marcadas aqui estão relacionados à magnitude aparente da estrela, uma medida de seu brilho aparente. Os pontos maiores representam estrelas mais brilhantes. As letras gregas marcam as estrelas mais brilhantes da constelação. Elas são classificadas por brilho, com a estrela mais brilhante sendo rotulada como alfa, a segunda mais brilhante como beta etc., embora essa ordem nem sempre seja seguida exatamente.
Crédito: Adaptado pelo Escritório de Astronomia para Educação da IAU a partir do original da IAU/Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Aquarius Constellation Map
Legenda: The constellation Aquarius along with its bright stars and surrounding constellations. Aquarius is surrounded by (going clockwise from the top) Pegasus, Equuleus, Aquila, Capricornus, Piscis Austrinus, Sculptor, Cetus and Pisces. Aquarius lies on the ecliptic (shown here as a blue line), this is the path the Sun appears to take across the sky over the course of a year. The Sun is in Aquarius from mid February to mid March. The other planets of the Solar System can often be found in Aquarius.
Aquarius spans the celestial equator and is thus visible at some time in the year from all of planet Earth. In the most arctic or antarctic regions of the world, some parts of the constellation may not be visible. Aquarius is most visible in the evenings in the northern hemisphere autumn and southern hemisphere spring.
The yellow circles with plus symbols superimposed on them mark the globular clusters M2 and M72. The green circles superimposed on plus symbols mark the planetary nebulae NGC 7293 (the Helix Nebula) and NGC 7002 (the Saturn Nebula). M73 (marked with an x symbol) is a coincident grouping of stars previously erroneously classified as an open cluster.
The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the line marking the ecliptic, nor the lines joining the stars appear on the sky.
Crédito: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Ursa Major Constellation Map
Legenda: The constellation Ursa Major along with its bright stars and its surrounding constellations. Ursa Major is surrounded by (going clockwise from the top): Draco, Camelopardalis, Lynx, Leo Minor, Leo, Coma Berenices, Canes Venatici and Boötes. Ursa Major is famous for the prominent asterism often known in English as the Big Dipper or the Plough. This prominent northern asterism has a wide variety of names from cultures across the world. While most constellations and asterisms are made up of unrelated stars that randomly appear close together on the sky, five of the stars in the Big Dipper are part of the Ursa Major Moving Group, a group of stars moving through space together that likely formed in the same location 300 million years ago. The two stars on the right-hand end of the Big Dipper on this diagram form a pair of pointer stars that can be used to locate Polaris, the northern pole star which lies in the constellation of Ursa Minor.
Ursa Major is a northern constellation and is visible from northern and equatorial regions. Parts of the constellation are visible from all but the most antarctic parts of the southern hemisphere but not all temperate regions of the southern hemisphere can see all of the Big Dipper. Conversely the Big Dipper and much of the rest of the constellation are circumpolar in arctic and many temperate regions of the northern hemisphere. Ursa Major is most visible in the evening in the northern hemisphere spring and southern hemisphere autumn.
Two prominent galaxies appear in the northern part of this constellation, the spiral galaxy M81 and M82, a possible spiral galaxy whose structure is difficult to observe from the Earth as it appears edge-on. Both are shown here as red ellipses. The planetary nebula M97 (the Owl Nebula) lies in the middle of the constellation and is marked by a green circle superimposed on a plus symbol.
The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Crédito: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Cygnus Constellation Map
Legenda: The constellation Cygnus with its bright stars and surrounding constellations. Cygnus is surrounded by (going clockwise from the top): Cepheus, Draco, Lyra, Vulpecula, Pegasus and Lacerta. Cygnus is notable for its brightest star Deneb. This forms one vertex of the prominent Summer Triangle asterism that is visible in northern hemisphere summer evenings.
Cygnus is a northern constellation and thus the whole of the constellation is visible at some point in the year in the whole northern hemisphere. The whole constellation is also visible from equatorial regions of the southern hemisphere with parts of the constellation visible from temperate southern regions.
The plane of the Milky Way runs through Cygnus and thus the constellation is rich in nebulae and star clusters. These include the North America Nebula (NGC 7000) and the Crescent Nebula (NGC 6888). The Veil Nebula is a huge supernova remnant, parts of which are marked here as NGC 6960 and NGC 6992/5. All of the previously-mentioned nebulae are marked with green squares. The planetary nebula NGC 6826 is marked here with a green circle superimposed on a plus sign. The open star clusters M29 and M39 are marked here with yellow circles.
The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Crédito: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Draco Constellation Map
Legenda: The constellation Draco with its bright stars and surrounding constellations. Draco is surrounded by (going clockwise from the top): Cepheus, Ursa Minor, Boötes, Hercules, Lyra and Cygnus.
Draco is a sprawling northern constellation, parts of which lie close to the celestial north pole. As such the whole constellation is visible at some point in the year from the whole northern hemisphere and a thin sliver of the southern hemisphere near the equator. Parts of the constellation are visible from all other southern equatorial and some southern temperate regions. Draco is best viewed in the evenings in the northern hemisphere summer and southern hemisphere winter.
The planetary nebula NGC 6543 (also known as the Cat’s Eye Nebula) lies in Draco. It is marked here with a green circle superimposed on a plus sign.
This diagram maps an area around the north celestial pole. Here lines of constant right ascension converge. The right ascension values of these lines are marked on the x-axis above and below the diagram. Some of the lines of constant declination are marked on the y-axis. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Crédito: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
