Editing Stellar classification (section)

=== Luminous blue variables ===
{{Main articles|Luminous blue variable}}
Luminous blue variables (LBVs) are rare, massive and evolved stars that show unpredictable and sometimes dramatic variations in their spectra and brightness. During their "quiescent" states, they are usually similar to B-type stars, although with unusual spectral lines. During outbursts, they are more similar to F-type stars, with significantly lower temperatures. Many papers treat LBV as its own spectral type.<ref>{{Cite journal |last1=Apellániz |first1=J. Maíz |last2=Barbá |first2=R. H. |last3=Aranda |first3=R. Fernández |last4=González |first4=M. Pantaleoni |last5=Bellido |first5=P. Crespo |last6=Sota |first6=A. |last7=Alfaro |first7=E. J. |date=2022-01-01 |title=The Villafranca catalog of Galactic OB groups – II. From Gaia DR2 to EDR3 and ten new systems with O stars |url=https://www.aanda.org/articles/aa/full_html/2022/01/aa42364-21/aa42364-21.html |journal=Astronomy & Astrophysics |language=en |volume=657 |pages=A131 |doi=10.1051/0004-6361/202142364 |arxiv=2110.01464 |bibcode=2022A&A...657A.131M |issn=0004-6361}}</ref><ref>{{Cite journal |last1=Massey |first1=Philip |last2=Neugent |first2=Kathryn F. |last3=Smart |first3=Brianna M. |date=2016-09-01 |title=A spectroscopic survey of massive stars in M31 AND M33* |journal=The Astronomical Journal |volume=152 |issue=3 |pages=62 |doi=10.3847/0004-6256/152/3/62 |doi-access=free |arxiv=1604.00112 |bibcode=2016AJ....152...62M |issn=0004-6256}}</ref>