List of star classes

This list of star classes is intended to provide an overview of the multitude of influencing factors that make up a special star class. In addition to the more familiar types of stars some former stars such as the main sequence and. B. Neutron stars, it lists the multitude of phenomena, which often represent either a further phase of star evolution or, due to a neighboring star , an interplay of two or more stars.

list

Separated from the subheadings, each star class is listed only once. Each part table therefore only contains those classes that meet the criterion and that have not already been listed.

Legend

Abbreviations of the column titles DS Double star V Variable star RS Giant star NS SL Neutron star or black hole WZ White dwarf

table

Star class	DS	V	RS	NS SL	WZ	Remarks	example
Base classes
Hypergiant	-	-		-	-	Luminosity class 0	R136a1
Super giant	-	-		-	-	Luminosity class I.	Betelgeuse
Bright giant	-	-		-	-	Luminosity class II	Sargas
Normal giant	-	-		-	-	Luminosity class III	Aldebaran
Sub giant	-	-		-	-	Luminosity class IV	Eta Cephei
Main sequence star	-	-	-	-	-	Luminosity class V, phase of stable hydrogen burning , longest phase with nuclear fusion	Sun
Subdwarf	-	-	-	-	-	Luminosity class VI or the prefix sd for sub-dwarf	US 708
White dwarf	-	-	-	-		Luminosity class VII	Sirius B.
Neutron star	-	-	-		-	-	Scorpius X-1
pulsar	-		-		-	-	Geminga
Brown dwarf	-	-	-	-	-	no star because of insufficient mass	Teide 1
Main sequence stars
Red dwarf	-	-	-	-	-	see also Flarestern	Proxima Centauri
Yellow dwarf	-	-	-	-	-	-	Sun
Main sequence star of the spectral class O	-	-	-	-	-	-	Zeta Ophiuchi
Cool sub-dwarf	-	-	-	-	-	Low-metal stars, types sdM to sdG	Kapteyn's star
UV Ceti star	-		-	-	-	Subclass of the red dwarfs and eruptive mutable	UV Ceti
Gamma Doradus star	-		-	-	-	young, pulsation-variable stars with spectral class F	Gamma Doradus
Pecular stars
Pecular star	-	-	-	-	-	also called CP star, different metal frequency compared to normal stars
Extreme helium star	-	-		-	-	Spectral class A or B	HD 124448
PV Telescopii star	-			-	-	peculiar pulsation-variable stars with spectral class B, see also Ap star	PV Telescopii
At the star	-	-	-	-	-	Spectral class A	Sirius A
Ap star	-	-	-	-	-	Spectral class A or B	V364 Carinae
Alpha2 Canum Venaticorum Star	-		-	-	-	peculiar rotationally variable stars	Alpha2 Canum Venaticorum
SX Arietis star	-		-	-	-	peculiar rotationally variable stars	SX Arietis
Lambda Bootis star	-	-	-	-	-	Spectral class B to F	Lambda Bootis
Barium star		-		-	-	Spectral class G or K	Zeta Capricorni
Carbon star	-	-		-	-	-	La Superba
CEMP star	-	-	-	-	-	high carbon content, low metal content	HD 196944
Mercury Manganese Star	-	-	-	-	-	-	Elnath
Technetium star	-			-	-	-	R Andromedae
Weak G-band star	-	-		-	-	Spectral class G or K	HD 165634
Classes with a giant star
Red supergiant	-			-	-	Luminosity class I and belong to the pulsation-variable stars	Betelgeuse
Luminous blue changer	-			-	-	Hypergiant	S Doradus
Blue hypergiant	-	-		-	-	-	Cyg OB2-12
Yellow hypergiant	-			-	-	belong to the pulsation-variable stars	Rho Cassiopeiae
Red hypergiant	-	-		-	-	-	NML Cygni
Wolf-Rayet star	-			-	-	belong to the Eruptive Variable Stars	WR 102ka
Yellow giant	-	-		-	-	-	Canopus
Blue giant	-	-		-	-	-	Alnitak
Red giant	-	-		-	-	-	Aldebaran
Mira star	-			-	-	Pulsation-variable red giants	Mira (star)
OH / IR star	-			-	-	Stage of development of a red giant	WX Piscium
Fixed OH / IR star	-	-		-	-	very late phase before the transition to the planetary nebula
AGB star	-			-	-	Stage of development of a red giant
Super terms and conditions star	-	-		-	-	massive red giants
Red Clump Star	-	-		-	-	-	Deneb Kaitos
Cepheids	-			-	-	Pulsation-variable stars	Delta Cephei
Anomalous Cepheids	-			-	-	Pulsation-variable stars	BL Bootis
RV Tauri star	-			-	-	Type II Cepheids: Pulsation-variable stars	RV Tauri
BL Herculis star	-			-	-	Type II Cepheids: Pulsation-variable stars	BL Herculis
W Virginis star	-			-	-	Type II Cepheids: Pulsation-variable stars	W Virginis
Ultra Long Period Cepheid	-			-	-	Pulsation-variable stars	BZ Tucanae
RR Lyrae star	-			-	-	Pulsation-variable stars with spectral classes A to F	RR Lyrae
Alpha Cygni star	-			-	-	Pulsation-variable stars	Deneb A (Alpha Cygni)
My Cephei stars	-			-	-	obsolete star class	Garnet star
Semi-regular variable star	-			-	-	-	Garnet star
Slowly irregularly changing star	-			-	-	-	U Antliae
R Coronae Borealis Star	-			-	-	Eruptive variable stars	R Coronae Borealis
DY Persei star	-			-	-	Eruptive variable stars - subclass of the RCB	DY Persei
RS Canum Venaticorum Star				-	-	Eruptive variable stars	RS Canum Venaticorum
FK Comae Berenices star	-			-	-	Rotationally variable stars with spectral class G or K.	FK Comae Berenices
Colliding-Wind Binary		-		-	-	-	Eta Carinae
Symbiotic star				-	-	Mutable with a red giant	R Aquarii
White dwarf as a compact object
ZZ Ceti star	-		-	-		pulsating white dwarfs	ZZ Ceti
GW Virginis star	-		-	-		pulsating white dwarfs	PG 1159-035
PG1159 star	-	-	-	-		late phase of stellar evolution to white dwarf, not necessarily with pulsations	PG 1159-035
Cataclysmic Mutable			-	-		Usually a binary star system with at least 1 white dwarf
AM Canum Venaticorum Star			-	-		Cataclysmic Mutable	AM Canum Venaticorum
SW sextantis star			-	-		Cataclysmic Variables (Red Dwarf and White Dwarf)	SW sextantis
nova			-	-		Cataclysmic Mutable	GK Persei
AM Herculis star			-	-		Cataclysmic Variables (English Polars)	AM Herculis
DQ Herculis star			-	-		Cataclysmic Variables (English Intermediate Polars)	DQ Herculis
Zwergnova (UG)			-	-		Cataclysmic Mutable	U Geminorum
SU Ursae Majoris Star (UGSU)			-	-		Cataclysmic Variables (subgroup of dwarf novae)	SU Ursae Majoris
SS Cygni Star (UGSS)			-	-		Cataclysmic Variables (subgroup of dwarf novae)	SS Cygni
Z Camelopardalis Star (UGZ)			-	-		Cataclysmic Variables (subgroup of dwarf novae)	Z camelopardalis
Super soft X-ray source (SSS)	-		-	-		Variable stars	QR Andromedae
EL Canum Venaticorum Star			-	-		Eclipsing stars	EL Canum Venaticorum
White dwarf, neutron star or black hole as a compact object
X-ray binary star			-		-	Double star system with white dwarf, neutron star or black hole
Microblazar			-		-	X-ray binary star with neutron star or black hole	Cygnus X-1 (candidate)
Microquasar			-		-	X-ray binary star with neutron star or black hole	GRS 1915 + 105
Supergiant Fast X-ray Transient (SFXT)					-	X-ray binary star with neutron star and supergiants
Symbiotic X-ray binary star (SyXB)					-	X-ray binary star with neutron star and red giant
Ultra-compact X-ray binary star (UCXB)			-			X-ray binary star with neutron star and white dwarf or helium star	SWIFT J1756.9–2508
Röntgennova (SXT)			-		-	X-ray binary star with neutron star or black hole	A0620−00
Very faint X-ray binary star			-		-	X-ray binary star with neutron star or black hole
Ultra-luminous X-ray source (ULX)			-		-	an X-ray binary star with an involved black hole or pulsar is suspected	M82 X-2
Gamma ray double star			-		-	Double star system with neutron star or black hole	Cygnus X-3
X-ray pulsar	-		-		-	-	Centaurus X-3
Gamma pulsar	-		-		-	-	Vela pulsar
Magnetar	-		-		-	-	SGR 1900 + 14
Soft gamma repeater	-	-	-		-	-	SWIFT J1822.3-1606
Central Compact Objects in Supernova Remnants	-	-	-		-	-	Cassiopeia A
Rotating radio transient (RRAT)	-		-		-	-	RRAT J1819-1458
X-ray Dim Isolated Neutron Stars	-	-	-		-	-	RX J1856-3754
Black widow		-	-		-	-	PSR B1957 + 20
Young stars
Protostar	-		-	-	-	early phase of stellar evolution	W75N (B) -VLA2
T-tauri star	-		-	-	-	young eruptive variable stars	T Tauri
EXor	-		-	-	-	young eruptive variable stars	EX Lupi
Herbig-Ae / Be star	-		-	-	-	young eruptive variable stars	HD 100546
UX Orionis star	-		-	-	-	young eruptive variable stars	UX Orionis
FU Orionis star	-		-	-	-	young eruptive variable stars	FU Orionis
Lindroos double star		-	-	-	-	Binary stars with primary component spectral class B, secondary component F to M	Regulus
Special classes
Compact star	-	-	-	-	-	A burned-out object after the end of the nuclear fusion. These include white dwarfs, neutron stars and stellar black holes.
Interactive double star		-	-	-	-	-
Hot sub-dwarf	-	-	-	-	-	Helium fusing stars, types sdB and sdO	KOI-55
Be star	-	-	-	-	-	Stars with spectral class B (or O / A)	EE Cephei
Gamma Cassiopeiae Analog	-		-	-	-	Eruptive variable stars - subclass of the Be stars	Gamma Cassiopeiae
Lambda Eridani star	-		-	-	-	Subclass of the Be stars	Lambda Eridani
B [e] star	-	-	-	-	-	also known as Bep star or BQ star
FS Canis Majoris Star	-		-	-	-	Eruptive variable stars - subclass of BQ resp. B [e] stars	FS Canis Majoris
Blue stragglers	-	-	-	-	-	-	40 Cancri
Yellow stragglers	-	-	-	-	-	-
Red stragglers	-	-	-	-	-	-
Runaway star	-	-	-	-	-	Stars at high speed	AE Aurigae
Fast runner	-	-	-	-	-	Stars at high speed	61 Cygni
Hyper-fast runner	-	-	-	-	-	Stars at high speed	US 708
Other variable classes
Pulsation-variable star	-		-	-	-	Pulsation-variable stars
Delta Scuti star	-		-	-	-	Pulsation-variable stars with spectral class A or F (main sequence and subgiants)	Delta Scuti
SX phoenix star	-		-	-	-	Pulsation-variable stars, which are counted among the blue laggards	SX Phoenicis
Beta Cephei star	-		-	-	-	Pulsation-variable stars with spectral class B (main sequence and subgiants)	Beta Cephei
Slowly pulsating B star	-		-	-	-	Pulsation-variable stars with spectral class B (main sequence and subgiants) - also called SPB	Zeta Pegasi
Blue Large-Amplitude Pulsator (BLAP)	-		-	-	-	Pulsation-variable stars
Heartbeat Star			-	-	-	Variable stars	KOI-54
Double period variable			-	-	-	Eruptive variable stars	V393 Scorpii
Rotationally variable star	-		-	-	-	-
BY-Draconis star	-		-	-	-	Rotationally variable stars of the spectral classes G to M	Epsilon Eridani
Ellipsoid variable star			-	-	-	Rotationally variable stars	Spica
Eclipsing star			-	-	-	-
Algolstern			-	-	-	Eclipsing stars	Algol
HW Virginis star			-	-	-	Eclipsing stars	HW Virginis
W Ursae Majoris Star			-	-	-	Coverage variable stere	W Ursae Majoris
Beta Lyrae Star			-	-	-	Eclipsing stars	Beta Lyrae
Bright red nova	-		-	-	-	Cataclysmic variables, presumably created by star collisions	V838 monocerotis
Hypothetical classes
Black dwarf	-	-	-	-		cold white dwarfs
Thorne Żytkow object	-	-			-	hypothetical object: giant star with a neutron star in the center	HV 2112 (candidate)
Dark star	-	-	-	-	-	-
Super massive star	-	-	-	-	-	-
Iron star	-	-	-	-	-	-
Gravastern	-	-	-	-	-	Alternative explanation of the black hole phenomenon
Shell collapses	-	-	-	-	-	Alternative explanation of the black hole phenomenon
Quark star	-	-	-	-	-	Hypothetical intermediate stage between neutron star and black hole	3C 58 (candidate)

Events related to star classes

event	DS	V	RS	NS	WZ	Remarks
Super flare	-	-	-	-	-	Extreme radiation burst (flare) from a sun-like star
Bright red nova	-		-	-	-	-
X-ray nova			-	-	-	Brightness outburst of an X-ray binary star
Dwarf Nova			-	-		cataclysmic mutable
nova			-	-		-
Kilonova			-	-	-	-
Supernova	-			-	-	-
Hypernova	-			-	-	-
Hypothetical events
Quark Nova	-		-		-	-
Un-nova	-			-	-	-

See also

• Hertzsprung-Russell diagram
• Spectral class
• Astronomical event
• planetary nebula