Glossary term: A型星

Description: A型星是指光譜類型為“A“的恆星。天文學家通過A型星光譜中存在的非常強的氫吸收線來識別它們。它們的典型（有效）溫度在7400 K到10,000 K之間。與其他恆星相比，除非受到星際或大氣層紅化的影響，否則它們在人眼中呈現白色或藍白色。天狼星是夜空中最亮的恆星，而織女星是所有其他恆星在視星等尺度上衡量其他星亮度的標準星，它們都是A型星。

Related Terms:

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

This is an automated transliteration of the simplified Chinese translation of this term

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".

If you notice a factual or translation error in this glossary term or definition then please get in touch.

Related Diagrams

A smooth line peaking about 420 nm then declining at longer wavelengths with a few fairly broad dips.

Spectrum of an A-type star

Caption: The spectrum of the A-type star BD-11 1212. 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. Lines from hydrogen atoms dominate the spectra of A-type stars and are strongest at this spectral type.
Credit: IAU OAE/SDSS/Niall Deacon

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

You may also be interested in

The Office of Astronomy for Education is hosted by the Haus der Astronomie on the campus of the Max Planck Institute for Astronomy in Heidelberg. The Office of Astronomy for Education is an office of the International Astronomical Union, with substantial funding from the Klaus Tschira Foundation and the Carl Zeiss Foundation. The Shaw-IAU Workshops on Astronomy for Education
are funded by the Shaw Prize Foundation.