MKCLASS: An expert stellar spectral classification system

MKCLASS is a program designed to classify stellar spectra on the MK system in a way similar to humans, via direct comparison with MK standards. The program is described in the following documents:


Documentation - Installation and Use

Journal paper (preprint)

Before you attempt to use MKCLASS, you may first wish to download and install the program XCLASS, which is a manual spectral classification program which uses the same standard spectrum libraries as MKCLASS. See below for documentation and source code for XCLASS.

Download source code and spectral libraries



Standards used in the spectral libraries

libnor36 standards

Version History

v1.07: Sept 10, 2015. General improvement of the quality of spectral types from B -- M, including improved recognition of carbon stars, Wolf Rayet stars, white dwarfs and other non-MK types. Improved classification of chemically peculiar stars. This is the version used to classify LAMOST spectra in the Kepler field (submitted).
v1.05: July 14, 2014. Upgraded quality evaluation of late-K and M-type stars.
v1.04: July 9, 2014. Improvements in the determination of the metallicity type of A and F-type stars.
v1.03: June 29, 2014. Introduced improvements in the identification of emission-line stars, and in the luminosity classification of mid A-type stars. Also introduced the use of an environment variable to take care of a non-standard location for the mklib standards libraries.
v1.02: Improved the classification of metal-weak A-type stars.
v1.01: Original distribution

Two Digital Spectral Classification Atlases

The Digital Spectral Classification Atlas v 1.07 (R.O. Gray)

The Digital Spectral Classification Atlas (by R.O. Gray) is an atlas based on spectra obtained (mostly) on the Dark Sky Observatory 0.8-m GM spectrograph. The illustrations are similar to those in the book Stellar Spectral Classification (Princeton University Press), and indeed, this atlas may be considered a synopsis of that book. The atlas may be downloaded here:


An Atlas of LAMOST Low-Resolution Spectra of Chemically Peculiar Stars (Stefan Hümmerich)

This spectral atlas is based on low-resolution spectra from the LAMOST telescope in China. It covers the chemically peculiar stars of the upper main sequence, including the Am, Ap, HgMn, He-peculiar and λ Bootis stars. This atlas may be downloaded here:

LAMOST CP Atlas (v1)

XCLASS: An aid to manual spectral classification

Download source code for XCLASS




Standard Spectral Libraries

You will also need to download the same spectral libraries employed by MKCLASS: