Betelgeuse

data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)

note (category: star names):

BETELGEUSE; Betelguex; Betelgeuze; Beteiguex; Al Mankib.

position, motion, parallax:

position (J2000)	RA: 5h 55min 10.3sec	DEC: +7° 24' 25''
position (B1900)	RA: 5h 49min 45.4sec	DEC: +7° 23' 19''
proper motion (J2000)	RA: 0.026 arcsec/a	DEC: 0.009 arcsec/a
radial velocity	21 km/s note: spectroscopic binaries
trigonometric parallax	0.005 arcsec
galactic coordinates	longitude: 199.79°	latitude: -8.96°

note (category: radial and/or rotational velocities):

Expanding circumstellar shell, extending at least 29" or about 600 stellar radii. If rate constant, initial potassium ejection about 2700 years ago. 2.85-cm radio emission indicates mass loss.

magnitude

visual magnitude

0.5
(V on UBV Johnson system)

spectral / color information

spectral class	M1-2Ia-Iab
B-V-magnitude	1.85
U-B-magnitude	2.06
R-I-magnitude
IR-note	object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

note (category: spectra):

Ultraviolet FeII emission. 5-micron observations indicate carbon monoxide. STRATOSCOPE II observations indicate infrared H2O bands. UV observations from OAO-2 indicate C and O underabundant. MgII emissions indicate a cooler shell surrounding the supergiant.

variability information

variable star identification

Alp Ori

note (category: variability):

ADS 4506A, SRc 0.40 - 1.3V, 2335d. Also superimposed waves 200-400d.

double/multiple star system information

number of components of multiple star system	6
separation	174.4 arcsec
mag difference (of double or brightest multiple)	9.9
component ID	AE

note (category: double and multiple data):

Components B-E all 11 to 14.5v at sep. 40" to 174" from A. D 13.5 at 77", optical. Speckle interferometric observations in 1983 November (Karovska et al. 1986, ApJ, 308, 360) show A to be a triple system with closer companion at 0.06" (mag. diff. 3.4 at H alpha) and more distant companion at 0.51" (mag. diff. 4.6 at H alpha).

note (category: spectroscopic binaries):

ADS 4506A, 5.781y, K 3.08k/s, V0 +20.33k/s, asini 81.773.

miscellaneous information

note (category: stellar radii or diameters):

The first star whose diameter was measured with the interferometer, .047", by Michelson and Pease at Mt. Wilson in 1920.

note (category: miscellaneous):

Radio star. Circumstellar shell of gas and dust. The gas shell detached from photosphere at about 5 stellar radii. Diam of optically thin dust shell possibly 1".5. Surrounded by reflection nebula. Gas shell up to 100 R, dust shell from 12 to 250 R. Highly limb darkened.

data from SKY2000 - Master Star Catalog (Myers+ 1997)

position, motion, parallax:

position (J2000)	RA: 5h 55min 10.307sec	DEC: +7° 24' 25.35''	±0.06 arcsec	source: 15
proper motion (J2000)	RA: 0.0017 arcsec/a	DEC: 0.009 arcsec/a		source: 25
radial velocity	21 km/s			source: 25
trigonometric parallax	0.005 arcsec		-	source: 25
galactic coord. (B1950)	longitude: 199.79°	latitude: -8.96°

magnitude:

visual	0.5 (observed)	source: 25
photovisual	0.9	source: 2

spectral information:

spectral class	M0		source: 96
Morgan-Keenan	M1-M2Ia-Iab		source: 25
B-magnitude	2.35 ±0.05	B-V-magnitude	1.85
U-magnitude	4.41 ±0.05	U-B-magnitude	2.06

variability information:

source of data: 30

variability type	192
var. amplitude	1.3
var. period	2335

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	0.5 arcsec
magnitude difference between brightest and second brightest component	14
position angle	278 °

sources:

2	HD and HDE Catalogs
Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University
15	FK5, FK5 Extension and FK5 Supplement
Fricke, W., H. Schwan and T. Lederle, "Fifth Fundamental Catalogue (FK5), Part I. The Basic Fundamental Stars," Veroff. Astronomisches Recheninstitut, No. 32, Heidelberg, Germany, 1988, and Fricke, W., H. Schwan, and T.E. Corbin, "Fifth Fundamental Catalogue (FK5), Part II. The FK5 Extension," Veröff. Astronomisches Recheninstitut, No. 33, Heidelberg, Germany, 1991
19	WDS Catalog
Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996
25	Bright Star Catalogue, 5th edition
Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994
30	GCVS, 4th edition
Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88
96	SAO or HD/HDE Catalog
Reference from Value 1 or Reference from Value 2

data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)

position and proper motion:

position (B1950)	RA: 5h 52min 27.809sec	DEC: +7° 23' 57.92''	±0.003 arcsec
position (J2000)	RA: 5h 55min 10.321sec	DEC: +7° 24' 25.43''
proper motion B1950 (FK4)	RA: 0.0017 arcsec/a	DEC: 0.01 arcsec/a	±0.001 arcsec/a in RA ±0.001 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0019 arcsec/a	DEC: 0.01 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	0.6 (accuracy: 2 decimals)
source of visual magnitude data	Arithmetic mean of maximum and minimum magnitudes of a variable star

spectral information:

spectral class	M0
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Variable star in visual magnitude in source catalog

catalogues

source catalogue	FK4, catalogue number: 224
Durchmusterung	BD+07 1055
Boss General Catalogue	7451
Henry Draper Catalogue	39801

data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

position and proper motion:

position (J2000)	RA: 5h 55.2min	DEC: +7° 24'
proper motion (J2000)	RA: 0 arcsec/a	DEC: 0 arcsec/a

double/multiple star system information:

component	year	number of measures	position angle	angular separation	magnitude of 1st component	magnitude of 2nd component	spectral class(es)	discoverer code
Aa	1940	1	92°	0.1''	0.9	-	-	H 39
Ab	1982	2	265°	0.5''	0.5	14.5	M	KAR 1
Ab	1983	2	278°	-	0.5	14.5	M	KAR 1
AB	1891	1	110°	39.8''	0.5	14.5	-	H 39
AC	1891	1	290°	62''	0.5	14.2	M	H 39
AD	1877	3	348°	76.8''	0.9	13.5	-	H 39
AE	1786	6	152°	161.8''	0.9	11	-	H 39
AE	1917	6	153°	174.4''	0.9	11	-	H 39

discoverer information:

discoverer code	discoverer	reference
H 39	Herschel, W.	-
KAR 1	Karovska et al	(Astrophys. J. 308, 260; 1986.)

notes:

note	H VI 39. Alpha Ori. An irregular variable, spectrum M1-2Ia-Iab. Two close companions have been reported, detected by speckle interferometry.

data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)

position:

position (equinox 1950.0)

RA: 5h 52min 27.8sec

DEC: +7° 23' 58''

variability informations:

variability type	SRC	pulsating variable star
magnitute at max. brightness	0
magnitute at min. brightness	1.3
photometric system	visual, photovisual or Johnson's V
period [d]	2335

spectral information

spectral class

M1-M2Ia-Ibe

references

to a study	Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph	Vol. I GCVS (see Kholopov et al. 1985-1988)

miscanellous

ID in the GCVS catalogue	60/9001
constellation	Orion
notes on existence	The star is equivalent to '0609004 del'.
There are notes in published catalog.

variability type description

variability type

description

SRC

Semiregular variables, which are giants or supergiants of intermediate and late spectral types showing noticeable periodicity in their light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to >2000 days, while the shapes of the light curves are rather different and variable, and the amplitudes may be from several hundredths to several magnitudes (usually 1-2 mag in V).

SRA
Semiregular late-type (M, C, S or Me, Ce, Se) giants displaying persistent periodicity and usually small (<2.5 mag in V) light amplitudes (Z Aqr). Amplitudes and light-curve shapes generally vary and periods are in the range of 35-1200 days. Many of these stars differ from Miras only by showing smaller light amplitudes;

SRB
Semiregular late-type (M, C, S or Me, Ce, Se) giants with poorly defined periodicity (mean cycles in the range of 20 to 2300 days) or with alternating intervals of periodic and slow irregular changes, and even with light constancy intervals (RR CrB, AF Cyg). Every star of this type may usually be assigned a certain mean period (cycle), which is the value given in the Catalogue. In a number of cases, the simultaneous presence of two or more periods of light variation is observed;

SRC
Semiregular late-type (M, C, S or Me, Ce, Se) supergiants (Mu Cep) with amplitudes of about 1 mag and periods of light variation from 30 days to several thousand days;

SRD
Semiregular variable giants and supergiants of F, G, or K spectral types, sometimes with emission lines in their spectra. Amplitudes of light variation are in the range from 0.1 to 4 mag, and the range of periods is from 30 to 1100 days (SX Her, SV UMa).

catalogues and names	Betelgeuse, a Ori, alf Ori, 58 Ori, HR 2061, HD 39801, SAO 113271, BD +7 1055, FK5: 224, WDS 05552+0724A
other names	Betelguex, Beteiguex, Betelgeuze, Al Mankib
constellation	Orion