Glossary term: Órbita
Description: Uma órbita é a trajetória de um objeto em movimento em um sistema em torno do centro de massa desse sistema, causada pela força gravitacional mútua entre os objetos do sistema. Para sistemas como o Sistema Solar, onde o corpo central é muito mais massivo do que os outros corpos, esse centro de massa fica dentro ou próximo ao objeto mais massivo (no caso do Sistema Solar, o Sol). Em um sistema estelar binário, o centro de massa em torno do qual as estrelas orbitam geralmente fica entre as duas estrelas. As órbitas são tipicamente elípticas, com o centro de massa do sistema localizado em um dos focos da elipse. O tamanho e a forma da órbita são definidos pelo semieixo maior e pela excentricidade da elipse. Órbitas mais excêntricas têm maior elipticidade. A maioria dos planetas do Sistema Solar possui excentricidades orbitais muito próximas de zero, por exemplo, Vênus (0,007) e Terra (0,017). As exceções são Mercúrio (0,206) e o planeta anão Plutão (0,244).
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See this term in other languages
Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
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
- Árabe: المدار
- Alemão: Umlaufbahn
- Inglês: Orbit
- Espanhol: Órbita
- Francês: Orbite
- Hindi: कक्षा
- Italiano: Orbita
- Marathi: कक्षा (ऑर्बिट)
- Chinês Simplificado: 轨道
- Chinês Tradicional: 軌道
Related Media
Jupiter's Rotation, by Vishal Sharma, India
Caption: Third place in the 2021 IAU OAE Astrophotography Contest, category Galilean moons: Jupiter’s Rotation, by Vishal Sharma, India.
This time-lapse beautifully shows the rotation of Jupiter and the passage of two Galilean moons on the right side of the frame. Jupiter completes one rotation in just under 10 hours and we see as the Great Red Spot makes its way from left to right. The two moons travel a noticeable fraction of their orbit in this short time. This image was taken in 2020 in the North of India.
Credit: Vishal Sharma/IAU OAE
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons
Jupiter Moons Movie2, by Nicolas Hurez, Paul-Antoine Matrangolo, and Carl Pennypacker, United States of America
Caption: Second place in the 2021 IAU OAE Astrophotography Contest, category Galilean moons.
This sequence shows the orbit of the four Galilean moons around the planet Jupiter. Almost two entire orbits of the innermost moon, Io, can be seen, with the other moons (Europa and Ganymede, but in particular Callisto) being further away, orbiting noticeably slower. The images were obtained in 2018 with the Las Cumbres Global Observatory at different locations on Earth, allowing a continuous sequence of images over approximately half a week without gaps during the day. With clear skies and over the course of several nights, the motion of the Galilean moons can also be observed with binoculars (ideally steady your elbows on a surface).
Credit: Nicolas Hurez, Paul-Antoine Matrangolo and Carl Pennypacker/IAU OAE
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons
Jupiter, Io and its shadow, by Ralf Burkart, Germany
Caption: First place in the 2021 IAU OAE Astrophotography Contest, category Galilean moons.
This time-lapse of Jupiter taken in 2017 from Germany beautifully illustrates the transit of one of the Galilean moons, Io, in front of Jupiter. As this is simply a moon casting a shadow on a planet it is equivalent to a lunar eclipse on Earth observed from further away. While the shadow of the moon is clearly visible from the beginning, it might be difficult to spot the moon itself against the background of the beautiful atmospheric bands of Jupiter the first time the video is seen. Watching it repeatedly allows appreciating the rapid motion and rotation in this fantastic observation.
Credit: Ralf Burkart/IAU OAE
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons
A órbita de beta Pictoris b
Caption: Esta série de imagens mostra o movimento orbital do planeta extrassolar (exoplaneta) beta Pictoris b. O planeta é o ponto brilhante em cada imagem. A estrela hospedeira do planeta está escondida atrás do círculo preto no centro de cada imagem. Isso é feito para remover a estrela hospedeira, muito mais brilhante, que de outra forma ofuscaria a luz do planeta. A órbita do planeta é vista de perfil. Observar a órbita dessa perspectiva faz parecer que o planeta se move ao longo de uma linha reta. Entre fevereiro de 2015 e novembro de 2016, beta Pictoris b parece se aproximar cada vez mais de sua estrela hospedeira. O planeta então se aproximou tanto da estrela que não foi visto por quase dois anos, depois reaparecendo do outro lado da estrela.
Credit: Consórcio ESO/Lagrange/SPHERE
credit link
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons
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