emission line star Comparison Table

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emission line star comparison table

Subject has energy release has spectral type has surface temperature has orbital period become has rotation velocity has optical brightness variation has observational problem has color has symbol has absorption line has ejection velocity has acronym has temperature has relative abundance has prototype has abundance has lifetime is a kind of has name designated with has emission line has observable variation time scale has use has synonym has definition has luminosity class has number of star

Ae star 10000 K white H I A star one or several Balmer lines A-type star with emission in one or several Balmer lines.

Be star 11000 to 28000 K 0.2 magnitudes or greater some difficulty in distinguishing between various kinds blue-white He I B star
R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
V 335, V 336, etc., when the double letter designations are exhausted
at least one of the Balmer lines at some time within a period of decades Non-supergiant B-type stars, which have shown emission in at least one of the Balmer lines at some time.

H and K emission line star cooler than G2 greater than 1000 Kelvin emission line star Ca II HK lines Late objects (F4 to M), which exhibit emission features in their Ca II HK lines.

Me star greater than 1000 Kelvin M star Star of spectral type M with emission lines in their spectra.

nova 10⁴⁴ ergs greater than 1000 Kelvin naked eye star 0.2 magnitudes or greater some difficulty in distinguishing between various kinds CV half the stars in the solar neighborhood are members of star systems emission line star
R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
V 335, V 336, etc., when the double letter designations are exhausted
within a period of decades nova peak brightness distance determination explosive variable A stars that undergoes an explosion during which its brightness increases by up to ten magnitudes. Usually the following phases are distinguished (in order of time): pre-maximum, principal, diffuse enhanced, Orion, nebular and post-nova. 2

O((f)) 35000 K very high blue-white He II rare 3 to 6 million years O star N III O-type stars in which N III is present in emission and He is strong in absorption.

O(f) 35000 K very high blue-white He II rare 3 to 6 million years O star N III and sometimes He II O-type stars in which N III is present in emission and He II is weakly present in absorption or emission.

Oe 35000 K very high blue-white He II rare 3 to 6 million years O star Balmer lines O star with emissions in the Balmer lines.

Oef 35000 K very high blue-white He II rare 3 to 6 million years O star He II λ4686 (double) Early O stars that show double emission lines in He II λ4686.

Of star 35000 K very high blue-white He II rare 3 to 6 million years peculiar star N III 4634-4641 and He II 4686 Peculiar O stars in which emission features at λλ4634-4641 from N III and 4686 from He II are present. They have a well-developed absorption spectrum, which implies that the excitation mechanism of the emission lines is selective, unlike that of Wolf-Rayet stars. The spectra of Of stars are usually variable, and the intensities of their emission lines vary in an irregular manner. Of stars belong to extreme Population I. All O stars earlier than 05 are Of.

P Cygni star greater than 1000 Kelvin P Cygni emission line star High-luminosity, early-type star, in which all lines have a P Cyg type profile (an emission component on the red side of the absorption line).

shell star B star, A star, F star greater than 1000 Kelvin emission line star A star in which two different types of line profiles co-exist.

supernova 10⁴⁹ to 10⁵¹ ergs greater than 1000 Kelvin 0.2 magnitudes or greater some difficulty in distinguishing between various kinds CV emission line star
R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
V 335, V 336, etc., when the double letter designations are exhausted
within a period of decades supernova peak brightness distance determination explosive variable A gigantic stellar explosion in which the star's luminosity suddenly increases by as much as a billion times. Most of the star's substance is blown off, leaving behind, at least in some cases, an extremely dense core which may be a neutron star.

T Tauri star cooler than G2 greater than 1000 Kelvin 0.2 magnitudes or greater some difficulty in distinguishing between various kinds emission line star
R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
V 335, V 336, etc., when the double letter designations are exhausted
within a period of decades nebular variable Also called T Tauri variable, a type of variable star of spectral classification F, G or K (giants above the main sequence on the Hertzsprung-Russell diagram) that loses an appreciable proportion of its mass in its (irregular) more luminous periods, and is thus surrounded by volumes of gas and dust.

UV Ceti star dKe star, dMe star greater than 1000 Kelvin d UV Ceti dwarf hydrogen main sequence star Late-type dwarfs with spectra showing hydrogen emission lines. V

Wolf-Rayet O, B, A, and early F greater than 1000 Kelvin 2000 km s^-1 up to 50000 K emission line star He I, He II One of a class of very luminous, very hot (as high as 50000 K) stars whose spectra have broad emission lines (mainly He I and He II), which are presumed to originate from material ejected from the star at very high (~ 2000 km s^-1 ) velocities. Some W-R spectra show emission lines due to carbon (WC stars); others show emission lines due to nitrogen (WN stars). (Hiltner and Schild classification: WN-A, narrow lines; WN-B, broad lines.)

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Subject	has energy release	has spectral type	has surface temperature	has orbital period	become	has rotation velocity	has optical brightness variation	has observational problem	has color	has symbol	has absorption line	has ejection velocity	has acronym	has temperature	has relative abundance	has prototype	has abundance	has lifetime	is a kind of	has name designated with	has emission line	has observable variation time scale	has use	has synonym	has definition	has luminosity class	has number of star
Ae star			10000 K						white		H I								A star		one or several Balmer lines				A-type star with emission in one or several Balmer lines.
Be star			11000 to 28000 K				0.2 magnitudes or greater	some difficulty in distinguishing between various kinds	blue-white		He I								B star	R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted V 335, V 336, etc., when the double letter designations are exhausted	at least one of the Balmer lines at some time	within a period of decades			Non-supergiant B-type stars, which have shown emission in at least one of the Balmer lines at some time.
H and K emission line star		cooler than G2	greater than 1000 Kelvin																emission line star		Ca II HK lines				Late objects (F4 to M), which exhibit emission features in their Ca II HK lines.
Me star			greater than 1000 Kelvin																M star						Star of spectral type M with emission lines in their spectra.
nova	10⁴⁴ ergs		greater than 1000 Kelvin		naked eye star		0.2 magnitudes or greater	some difficulty in distinguishing between various kinds					CV				half the stars in the solar neighborhood are members of star systems		emission line star	R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted V 335, V 336, etc., when the double letter designations are exhausted		within a period of decades	nova peak brightness distance determination	explosive variable	A stars that undergoes an explosion during which its brightness increases by up to ten magnitudes. Usually the following phases are distinguished (in order of time): pre-maximum, principal, diffuse enhanced, Orion, nebular and post-nova.		2
O((f))			35000 K			very high			blue-white		He II				rare			3 to 6 million years	O star		N III				O-type stars in which N III is present in emission and He is strong in absorption.
O(f)			35000 K			very high			blue-white		He II				rare			3 to 6 million years	O star		N III and sometimes He II				O-type stars in which N III is present in emission and He II is weakly present in absorption or emission.
Oe			35000 K			very high			blue-white		He II				rare			3 to 6 million years	O star		Balmer lines				O star with emissions in the Balmer lines.
Oef			35000 K			very high			blue-white		He II				rare			3 to 6 million years	O star		He II λ4686 (double)				Early O stars that show double emission lines in He II λ4686.
Of star			35000 K			very high			blue-white		He II				rare			3 to 6 million years	peculiar star		N III 4634-4641 and He II 4686				Peculiar O stars in which emission features at λλ4634-4641 from N III and 4686 from He II are present. They have a well-developed absorption spectrum, which implies that the excitation mechanism of the emission lines is selective, unlike that of Wolf-Rayet stars. The spectra of Of stars are usually variable, and the intensities of their emission lines vary in an irregular manner. Of stars belong to extreme Population I. All O stars earlier than 05 are Of.
P Cygni star			greater than 1000 Kelvin													P Cygni			emission line star						High-luminosity, early-type star, in which all lines have a P Cyg type profile (an emission component on the red side of the absorption line).
shell star		B star, A star, F star	greater than 1000 Kelvin																emission line star						A star in which two different types of line profiles co-exist.
supernova	10⁴⁹ to 10⁵¹ ergs		greater than 1000 Kelvin				0.2 magnitudes or greater	some difficulty in distinguishing between various kinds					CV						emission line star	R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted V 335, V 336, etc., when the double letter designations are exhausted		within a period of decades	supernova peak brightness distance determination	explosive variable	A gigantic stellar explosion in which the star's luminosity suddenly increases by as much as a billion times. Most of the star's substance is blown off, leaving behind, at least in some cases, an extremely dense core which may be a neutron star.
T Tauri star		cooler than G2	greater than 1000 Kelvin				0.2 magnitudes or greater	some difficulty in distinguishing between various kinds											emission line star	R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted V 335, V 336, etc., when the double letter designations are exhausted		within a period of decades		nebular variable	Also called T Tauri variable, a type of variable star of spectral classification F, G or K (giants above the main sequence on the Hertzsprung-Russell diagram) that loses an appreciable proportion of its mass in its (irregular) more luminous periods, and is thus surrounded by volumes of gas and dust.
UV Ceti star		dKe star, dMe star	greater than 1000 Kelvin							d						UV Ceti			dwarf		hydrogen			main sequence star	Late-type dwarfs with spectra showing hydrogen emission lines.	V
Wolf-Rayet		O, B, A, and early F	greater than 1000 Kelvin									2000 km s^-1		up to 50000 K					emission line star		He I, He II				One of a class of very luminous, very hot (as high as 50000 K) stars whose spectra have broad emission lines (mainly He I and He II), which are presumed to originate from material ejected from the star at very high (~ 2000 km s^-1 ) velocities. Some W-R spectra show emission lines due to carbon (WC stars); others show emission lines due to nitrogen (WN stars). (Hiltner and Schild classification: WN-A, narrow lines; WN-B, broad lines.)