Glossary term: Estrela tipo K
Description: Uma estrela com tipo espectral “K”. Os astrônomos identificam as estrelas do tipo K pela presença de linhas de hidrogênio muito fracas, mas linhas fortes de átomos de ferro e manganês em seus espectros. Elas têm temperaturas típicas (efetivas) entre cerca de 3700 kelvins (K) e 5200 K. Em comparação com outras estrelas, elas parecem laranja-esbranquiçadas ao olho humano, a menos que o avermelhamento interestelar ou atmosférico seja significativo. Exemplos de estrelas do tipo K são Aldebaran, em Touro, e Pollux, em Gêmeos.
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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: النجم من النوع الطيفي K
- Alemão: K-Stern
- Inglês: K-type Star
- Francês: Étoile de type K
- Italiano: Stella di tipo K
- Japonês: K型星 (external link)
- Chinês Simplificado: K 型星
- Chinês Tradicional: K 型星
Related Diagrams
Spectrum of a K-type star
Caption: The spectrum of the K-type star 2MASS J19554455+4754531. The colour of the line between 400 nm and 700 nm roughly corresponds to the colour the human eye would see light of that wavelength. Below 400 nm and above 700 nm, where the human eye can see little to no light, the lines are coloured blue and red respectively.
The black lines show spectral absorption lines caused by atoms and ions of different elements in the star’s atmosphere. These atoms and ions absorb at specific wavelengths, causing sharp, dark lines in the spectra. How strong these lines are depends on the temperature of the star’s atmosphere. Two stars made from the same mix of elements could have spectra with vastly different sets of lines in their spectra if they have different temperatures in their atmospheres. The spectra of K-type stars are dominated by metal atoms such as iron, sodium and calcium atoms. There are so many lines from metal atoms, far too many to mark individually, that the spectrum has a choppy, ragged appearance. The lines of hydrogen atoms and calcium ions are much weaker than in the hotter G-type stars.
Credit: IAU OAE/SDSS/Niall Deacon
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons
