Documentos e recursos — Resultados da busca
Resultados da busca
Cometa 67P/Churyumov-Gerasimenko
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Legenda: O núcleo do cometa 67P/Churyumov–Gerasimenko é uma “bola de neve suja” composta por uma mistura de materiais congelados e poeira. Ele tem a forma de dois grandes lóbulos: um com 4,1 km × 3,3 km × 1,8 km e outro com 2,6 km × 2,3 km × 1,8 km. Esses lóbulos estão ligados por uma pequena ponte. Quando um núcleo cometário como este se aproxima do Sol, seu material congelado é aquecido, transformando-se em gás. Isso, combinado com a poeira incorporada, fornece o material para a coma e a cauda características do cometa.
Crédito: ESA/Rosetta/NAVCAM
Link do crédito
Termos do Glossário:
Cometa , Núcleo cometário
Categorias
Sistema Solar
Licença: Creative Commons Attribution-ShareAlike 3.0 IGO Creative Commons Attribution-ShareAlike 3.0 IGO ícones
Arquivo
( imagem
4.75 MB)
Big Dipper and Comet Neowise C2020 F3
vídeo
Criado para o OAE
Legenda: Honorable mention in the 2023 IAU OAE Astrophotography Contest, category of Time-lapses of rotation of Big Dipper or Southern Cross.
This time-lapse documents the trajectory of the iconic Big Dipper across three frames taken in July 2020. Captured from three locations in Italy, Tre Cime di Lavaredo Auronzo di Cadore, Monte Rite, Cibiana di Cadore, and Casera Razzo, Vigo di Cadore, this visual odyssey showcases the captivating journey of the Big Dipper with the addition of trails of stars painting a celestial canvas. It not only traces the path of this renowned asterism but also features the rare appearance of comet Neowise C/2020 F3, an extraordinary event that graced our skies during July 2020.
Crédito: Giorgia Hofer/IAU OAE (CC BY 4.0)
Termos do Glossário:
A Grande Concha (Big Dipper, em inglês) , Polo Celeste , Esfera Celeste , Estrelas circumpolares , Polaris , Céu , Rotação
Categorias
Astronomia a Olho Nu
Tags:
astrophotography
Licença: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Este arquivo no Zenodo ( vídeo 51.23 MB)
Comet C/2020F3 (Neowise) with separate dust and ion gas tails and a green glowing coma, by Dietmar Gutermuth, Germany
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Criado para o OAE
Legenda: Second place in the 2021 IAU OAE Astrophotography Contest, category Comets.
Comets have a very interesting structure comprising of four main parts: the nucleus, composed of rock, dust and frozen gases, typically spanning a few kilometres, although bigger ones have been observed; a small atmosphere of gas surrounding the nucleus (only present when the comet approaches its closest point to the Sun), called coma; and the two distinctive cometary tails (there is at times third tail). The green colour of the coma is due to carbon and nitrogen present in the coma reacting with the Sun’s ultraviolet radiation. The tail that we are mostly used to observing – dust tail and is composed of micron sized dust particles, the second tail composed of charged particles – ion or gas tail. The tails are released only when the comet approaches the Sun at a distance where the heat and radiation emanating from our star is intense enough to vaporize the frozen gases. The dust tail is curved, while the gas tail is straight and always points away from the Sun as this is carried by the solar wind - flow of charged particles emitted by the Sun. As comets are formed by leftover material, they carry with them important information about the early stages of the Solar System’s formation. This beautiful image shows the comet C/2020 F3 (Neowise), as seen from Germany in July 2020, with three of the four structures clearly visible – coma, gas, and dust tail.
Crédito: Dietmar Gutermuth/IAU OAE
Termos do Glossário:
Coma cometária , Cometa , Cauda de cometa
Categorias
Sistema Solar
Licença: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Este arquivo no Zenodo ( imagem 683.77 kB)
Neowise's metamorphosis, by Tomáš Slovinský and Petr Horálek, Slovakia
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Criado para o OAE
Legenda: First place in the 2021 IAU OAE Astrophotography Contest, category Comets.
This image uses the chronophotography technique to capture the evolution of the comet C/2020 F3 (Neowise) over time, as it became visible in the northern skies in July 2020. Orbits of comets are extremely elliptical, which means that during part of their orbit they get close to the Sun. As a comet approaches the Sun, it gets heated, releases gas and dust creating an envelope or coma around the nucleus. The solar wind and photons (particles of electromagnetic radiation) interact with the coma producing the cometary tail, which can be seen clearly in this image. The tail of a comet always points away from the Sun, and extends as much as tens of millions of kilometres. This tail has two parts: the relatively straight bluish gas (ion or plasma) tail, which is made up of charged particles interacting with the magnetic fields of the solar wind; and the whitish dust tail compose of very small dust particles that are pushed by the radiation pressure from the Sun into a curve due to their slower speeds. Two regions in the Solar System are often associated with being “storehouses” of comets: the Kuiper Belt and the Oort Cloud. Comets with periods up to about two hundred years come from the Kuiper belt, a reservoir of cometary nuclei material with a disk-like shape located beyond Neptune. Longer period comets come from the Oort cloud, another huge reservoir of icy objects, with a spherical shape surrounding the Solar System. The outer limit of the Oort Cloud is not known as yet, but it could be as much as 10 thousand times the Sun-Earth distance, or even more. Due to gravitational disturbances, some of these cometary nuclei might be ejected towards the inner regions of the Solar System, sometimes approaching the Earth, offering some of the most spectacular views of a celestial body. The image also shows some prominent constellations and asterisms like the Big and Little Dippers, and also the North (Pole) Star – Polaris.
Crédito: Tomáš Slovinský and Petr Horálek/IAU OAE
Termos do Glossário:
Cometa
Categorias
Astronomia a Olho Nu
, Sistema Solar
Licença: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Este arquivo no Zenodo ( imagem 19.53 MB)
Gemini meteor shower, by Hao Yin, China
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Criado para o OAE
Legenda: Third place in the 2021 IAU OAE Astrophotography Contest, category Meteor showers.
As the Earth travels around the Sun, it may cross the path of debris left behind by a comet or, more rarely, by an asteroid. These debris enter the atmosphere at high speed, producing beautiful tracks as they burn in the sky due to friction with the atmosphere. The image captures the Geminid meteor shower, named because the radiant point is located on the sky in the constellation Gemini. The particles composing the meteor shower travel at similar speed and in parallel trajectories, which causes a perspective effect like if the stream radiates from one single point in the sky, which is known as the radiant point. This image, taken in December 2020 in China, clearly shows this perspective. This is a very prolific shower, in such a way that over one hundred meteorites could be seen per hour in recent appearances. This meteor shower is one of the few associated not with a comet, but with an asteroid – 3200 Phaeton, which might be a comet that lost all its volatile material. This image shows the large number of meteors that can be observed in this shower, which always happens in December every year. The image also shows one of the most prominent constellations in the night sky, Orion, easily seen by the three stars in a diagonal making up Orion’s Belt, and the red-orange star Betelgeuse. Right above the dish is a bright point and that is the Sirius, the brightest star in the night sky and part of the constellation Canis Major. The fuzzy bluish smudge at around 2 ‘o’ clock is the Pleiades star cluster.
Crédito: Hao Yin/IAU OAE
Termos do Glossário:
Estrela cadente
Categorias
Astronomia a Olho Nu
Licença: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) ícones
Este arquivo no Zenodo ( imagem 9.78 MB)
