Zeta1 Scorpii

For other stars with this Bayer designation, see Zeta Scorpii.
ζ1 Scorpii
Location of ζ1 Scorpii (circled) 	
Location of ζ1 Scorpii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS) 	Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation 	Scorpius
Right ascension 	16h 53m 59.72650s[1]
Declination 	−42° 21′ 43.3063″[1]
Apparent magnitude (V) 	4.705[2](4.66 to 4.86)[3]
Characteristics 	Characteristics
Spectral type 	B1.5 Iae[4]
U−B color index 	−0.567[2]
B−V color index 	
Variable type 	SDOR:[3]
Astrometry 	Astrometry
 	
Radial velocity (Rv) 	−26.0[5] km/s
Proper motion (μ) 	RA: −1.01[1] mas/yr
Dec.: −4.01[1] mas/yr
Parallax (π) 	1.27 ± 0.25[1] mas
Distance 	approx. 2,600 ly
(approx. 800 pc)
Absolute magnitude (MV) 	−8.5[4]
 	
Details 	Details
 	
Mass 	36[4] M☉
Radius 	103[4] R☉
Luminosity (bolometric) 	850,000[4] L☉
Surface gravity (log g) 	1.7[4] cgs
Temperature 	17,200[4] K
Rotational velocity(v sin i) 	60[6] km/s
Age 	6.5 ± 0.1[7] Myr
 	
Other designations 	Other designations
ζ1 Sco, Zeta1 Scorpii, Zeta1 Sco, CD−42 11633, CPD−42 7545, GC 22730, HD 152236, HIP 82671, HR 6262, PPM 322342, SAO 227375.[8]	ζ1 Sco, Zeta1 Scorpii, Zeta1 Sco, CD−42 11633, CPD−42 7545, GC 22730, HD 152236, HIP 82671, HR 6262, PPM 322342, SAO 227375.[8]
Database references 	Database references
SIMBAD 	data
Zeta1 Scorpii (Zeta1 Sco, ζ1 Scorpii, ζ1 Sco) is a B-type hypergiant star in the constellation of Scorpius.[8] It has an apparent visual magnitude which varies between 4.66 and 4.86.[3] It is a member of the Scorpius OB1 association,[9] and the open star cluster NGC 6231, also known as the "northern jewel box" cluster. Around 36 times as massive as the Sun, it is also one of the most luminous stars known in the Galaxy, with an estimated bolometric luminosity of around 850,000 times that of the Sun and a radius 103 times that of the Sun.[4]
The stellar wind from this supergiant is expelling matter from the star at the rate of 1.55 × 10−6 solar masses per year, or roughly the equivalent to the Sun's mass every 640,000 years.[4]
ζ1 Scorpii forms a naked eye double with ζ2 Scorpii, but the stars are merely coincidentally near in the line of sight from Earth. ζ2 is a mere 155 light years distant and much less luminous in real terms. ζ1 Scorpii can also be distinguished from ζ2, due to the latter's orange hue especially in long-exposure photographs.
== References[edit] ==
# ^ Jump up to:a b c d e  Note: see VizieR catalogue I/311.
# ^ Jump up to:a b c 
# ^ Jump up to:a b c zet 1 Sco, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 20, 2009. (Quick look: Zet+1+Sco)
# ^ Jump up to:a b c d e f g h i 
# Jump up^ 
# Jump up^ 
# Jump up^ 
# ^ Jump up to:a b HIP 82671 -- Emission-line Star, database entry, SIMBAD. Accessed on line November 20, 2009.
# Jump up^ Zeta-1 Sco, Stars, Jim Kaler. Accessed on line November 20, 2009.
[hide]
* v
* t
* e
Stars of Scorpius	[hide]
* v
* t
* e
Stars of Scorpius
 	
Bayer 	
* α (Antares)
* β (Acrab)
* δ (Dschubba)
* ε
* ζ1
* ζ2
* η
* θ (Sargas)
* ι1
* ι2
* κ (Girtab)
* λ (Shaula)
* μ1 (Denebakrab)
* μ2
* ν (Jabbah)
* ξ
* ο
* π
* ρ
* σ (Al Niyat)
* τ (Alniyat)
* υ (Lesath)
* χ
* ψ
* ω1
* ω2
* G (γ Tel)
* H (β Nor)
* N (α Nor)
* Q
 	
Flamsteed	
* 1
* 2
* 3
* 4
* 11
* 12
* 13
* 16
* 18
* 22
* 25
* 27
 	
Variable 	
* T
* U
* RR
* RS
* RV
* RY
* RZ
* AH
* AI
* AK
* AR
* BM
* CL
* FQ
* HK
* KQ
* V393
* V453
* V455
* V482
* V500
* V636
* V701
* V703
* V718
* V745
* V760
* V856
* V861
* V866
* V893
* V900
* V905
* V906
* V907
* V911
* V913
* V915
* V918
* V919
* V921
* V922
* V923
* V929
* V933
* V949
* V951
* V952
* V957
* V965
* V970
* V973
* V975
* V992
* V1003
* V1007
* V1018
* V1026
* V1034
* V1036
* V1040
* V1051
* V1058
* V1068
* V1073
* V1074
* V1075
* V1077
* V1094
* V1104
* V1186
* V1187
* V1280
* V1292
* V1294
* V1309
 	
HR 	
* 5906
* 5910
* 5934
* 5965
* 5969
* 5973
* 5996
* 5998
* 5999
* 6000
* 6001
* 6003
* 6006
* 6007
* 6012
* 6015
* 6017
* 6044
* 6051
* 6053
* 6054
* 6061
* 6070
* 6076
* 6077
* 6078
* 6080
* 6094
* 6097
* 6100
* 6106
* 6122
* 6145
* 6160
* 6178
* 6192
* 6206
* 6209
* 6210
* 6211
* 6214
* 6218
* 6221
* 6244
* 6260
* 6266
* 6272
* 6273
* 6282
* 6298
* 6311
* 6316
* 6331
* 6338
* 6344
* 6366
* 6371
* 6381
* 6382
* 6389
* 6398
* 6403
* 6405
* 6409
* 6420
* 6454
* 6456
* 6460
* 6470
* 6501
* 6503
* 6517
* 6523
* 6539
* 6557
* 6558
* 6583
* 6587
* 6597
* 6613
* 6628
* 6643
* 6648
* 6649
* 6651
* 6653
* 6657
* 6658
* 6668
* 6671
* 6675
* 6678
* 6682
* 6683
 	
HD 	
* 143567
* 144432
* 145377
* 146436
* 150248
* 150420
* 152424
* 153234
* 153950
* 155985
* 158042
* 159868
* 162020
 	
Gliese 	
* Gliese 618
* Gliese 667
* Gliese 682
 	
Other 	
* CD -35 11760
* CD -38 10980
* EPIC 204278916
* GCRT J1745-3009
* GRO J1655-40
* GSC 06214-00210
* GX 340+0
* GX 349+2
* H1-36
* H1743-322
* HIP 79431
* IGR J17091-3624
* IGR J17252-3616
* IRAS 17163-3907
* MOA-2008-BLG-310L
* MXB 1735-44
* OAO 1657-415
* OGLE-2005-BLG-071L
* OGLE-2005-BLG-390L
* OGLE-2006-BLG-109L
* OGLE-2007-BLG-368L
* Pismis 24-1
* PSR B1620-26
* PSR B1706-44
* PSR B1737-30
* PSR J1614–2230
* Rapid Burster
* 1RXS J160929.1-210524
* 1RXS J170849.0-400910
* Scorpius X-1
* Th 28
* 4U 1700-37
* 4U 1702-42
* 4U 1705-44
* 4U 1724-307
* 4U 1728-34
* 4U 1746-371
* UScoCTIO 108
* WASP-17
* WR 86
* WR 93b
* Wray 17-96
* XTE J1720-318
* XTE J1739-302
* XTE J1751-305
 	
* List 	
* List
Categories: 
* Scorpius (constellation)
* B-type hypergiants
* Hipparcos objects
* Bayer objects
* Henry Draper Catalogue objects
* Emission-line stars