This page describes an image Spectrum of a B-type star

Download File ( image 76.71 kB)
Download PDF File (PDF file 73.33 kB)

Caption: The spectrum of the B-type star HD 258982. 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. For B-type stars the most important lines are caused by helium atoms. These lines are strongest in B-type stars and weaker in hotter and cooler types. Lines from hydrogen atoms are also present but are not as strong as in cooler A-type stars.

Credit: IAU OAE/SDSS/Niall Deacon.

Related glossary terms: B-type Star , Spectrum , Wavelength
Categories: Stars

Created with support from: OAE Main Office Main Office

License: Creative Commons Attribution 4.0 International (CC BY 4.0) Creative Commons Attribution 4.0 International (CC BY 4.0) icons

Want to make your own version of this diagram? Then have a look at the code that produced this diagram on Github

The diagram captions presented on the OAE website were written, translated 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 for our translation project here. All media file captions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE". The media files themselves may have different licenses (see above) and should be credited as listed above under "credit".