Editing Stellar classification (section)

===Mount Wilson classes===
A luminosity classification known as the Mount Wilson system was used to distinguish between stars of different luminosities.<ref name="Nassau1946">{{cite journal |title=Spectra of BD Stars Within Five Degrees of the North Pole |journal=Astrophysical Journal |first1=J. J. |last1=Nassau |first2=Carl K. |last2=Seyfert |volume=103 |page=117 |date=March 1946 |doi=10.1086/144796 |bibcode=1946ApJ...103..117N}}</ref><ref name="FitzGerald1969">{{cite journal |title=Comparison Between Spectral-Luminosity Classes on the Mount Wilson and Morgan–Keenan Systems of Classification |journal=Journal of the Royal Astronomical Society of Canada |first=M. Pim |last=FitzGerald |volume=63 |page=251 |date=October 1969 |bibcode=1969JRASC..63..251P}}</ref><ref name="Sandage1969">{{cite journal |title=New subdwarfs. II. Radial velocities, photometry, and preliminary space motions for 112 stars with large proper motion |journal=Astrophysical Journal |first=A. |last=Sandage |volume=158 |page=1115 |date=December 1969 |doi=10.1086/150271 |bibcode=1969ApJ...158.1115S|doi-access=free }}</ref> This notation system is still sometimes seen on modern spectra.<ref name="Norris2011">{{cite journal |title=Non-detection of the Putative Substellar Companion to HD 149382 |journal=The Astrophysical Journal |first1=Jackson M. |last1=Norris |first2=Jason T. |last2=Wright |first3=Richard A. |last3=Wade |first4=Suvrath |last4=Mahadevan |author4-link=Suvrath Mahadevan |first5=Sara |last5=Gettel |volume=743 |issue=1 |at=88 |date=December 2011 |doi=10.1088/0004-637X/743/1/88 |bibcode=2011ApJ...743...88N |arxiv=1110.1384|s2cid=118337277 }}</ref>
* sd: subdwarf
* d: dwarf
* sg: subgiant
* g: giant
* c: supergiant