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Variable Stars
- Be: Be Stars
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- FU: FU Orionis Stars
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- GCAS: Gamma Cassiopeiae Stars
- Rapidly rotating Be III-IV stars.
Examples: Gamma Cas, Pleione (BU Tau)
- I: Irregular variable
- Poorly known and/or studied irregular variable
- IA:
- Poorly studied irregular of early spectral type (O-A)
- IB:
- Poorly studied irregular variable of later spectral type (F-M)
- IN: Irregular nebulous variables
- Nebular or Orion variables, irregular variables associated with
bright diffuse nebulae.
- INA:
- Orion variables of early spectral type (O-A)
- INB:
- Orion variables of later spectral type (F-M)
- INT:
- T Tauri star
- IS:
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- ISA:
- of early spectral type (O-A)
- ISB:
- of later spectral type (F-M)
- RCB: R Coronae Borealis (R CrB) stars
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- RS: RS Canum Venaticorum (RS CVn) stars
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- SDor, S Dor: S Doradus stars
- also Hubble-Sandage variables
Examples: Eta Carinae, P Cygni, S Doradus in LMC
- UV: UV Ceti stars, flare stars
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- UVN: Flaring nebular (Orion) variables
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- WR: Wolf-Rayet stars
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- Cep: Delta Cephei stars, Cepheid variables
- Named after Delta Cephei, the second of these stars discovered
(by English amateur John Goodricke in 1784; first was Eta Aql,
discovered by Edward Pigott in the same year). These are supergiants
of spectral types F, G, K which pulsate with a period of a few to
almost 100 days and an amplitude between 0.1 and 2 magnitudes.
Cepheids are normally evolved stars which habve used up, after their
hydrogen, also their helium in the core. There are type I (Delta
Cephei) and type II (W Virginis) Cepheids, distinguished by chemical
composition and membership in different stellar populations (type I
Cepheids are found in population I, i.e. spiral arms and irregular
galaxies, type II in population II, globular clusters, galactic halos
and ellipticals), and different period-luminosity relations (for the
same period, type I Cepheids are typically about 1.5 magnitudes
brighter).
- DCep: Delta Cephei stars
- "Classical" cepheids, belonging to population I (spiral arms,
irregular galaxies), typically with long periods. There is a
subclass with almost symmetric light curves.
- CW: W Virginis Stars, Cepheids type II
- Cepheids belonging to stellar population II, the old stellar
population (galactic halos, globular clusters, elliptical
galaxies). Two period ranges are preferred:
- CWA: long-period (> 8d) W Virginis stars
- 10-30 days (Ex: W Vir)
- CWB, BL Her:
short-period (< 8d) W Vir stars or BL Her stars
- 1-4 days (Ex: BL Her)
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AM Her
BL Her
BY Dra
Cep: Cepheids: DCep, CW (W Vir)
CW: W Vir/type II Cep: CWA (W Vir), CWB (BL Her)
CWA: W Vir
CWB: BL Her
DCep: Delta Cephei
I: Irregular variable
IA
IB
IN
INA
INB
INT: T Tauri stars
IS
ISA
ISB
RCB
RS
SDor, S Dor: S Doradus stars
UV
UVN
WR: Wolf-Rayet stars
- Robert A. Garfinkle, Star-Hopping. 1994 Cambridge UP,
ISBN 0-521-59889-3, esp. p. 13 and Table A.3 (p. 270)
- Alan Hirshfeld and Roger W. Sinnott,
Sky Catalogue 2000.0, Volume 2: Double Stars, Variable Stars
and Nonstellar Objects. 1985 Cambridge UP and Sky Publishing,
ISBN 0-521-27721-3, p. xv ff and 223 ff.
- Cuno Hoffmeister, Gerold Richter and Wolfgang Wenzel,
Veränderliche Sterne. 2nd edition 1984, J.A. Barth,
Leipzig and Springer Verlag, ISBN 3-540-13396-8 and 0-387-13396-8
- Helen Sawyer Hogg, Variable Stars. P. 73-89 in:
Astrophysics and twentieth-century astronomy to 1950: Part A,
ed: Owen Gingerich, Volume 4A of The General History of Astronomy
series. 1984 Cambridge UP, ISBN 0-521-24256-8
- John E. Isles, Webb Society Deep-Sky Observer's Handbook, Volume 8:
Variable Stars; series edited by Kenneth Glyn Jones.
1990, Enslow Publishers, Hillside (NJ), ISBN 0-89490-208-3
- W. Strohmeier, Variable Stars. 1972, Pergamon Press, Oxford
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