Sigma Centauri — Double Star in Centaurus
Observe
1Physical Properties
Magnitude
3.91
Spectral Type
B2 V
Star Color
Blue
(B-V -0.19)
Distance
412 ly
2Position & Identifiers
RA
12h 28m 02.4s
Dec
-50° 13' 50.0"
Constellation
Centaurus
(Cen)
HR
4743
HIP
60823
HD
108483
SAO
223454
Bayer
Sigma
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3How easy to spot?
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Easy | Medium+ | Medium+ |
| 50 mm finder 50mm finder | Easy | Easy | Easy |
| 150 mm telescope 150mm scope | Easy | Easy | Easy |
Easy
Medium
Hard
Very hard
Impossible
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
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Best season
Feb – Apr
(peak: Mar)
5Multiple Star System
Separation
0.1″
Companion Mag
6.6
Position Angle
-1°
Star Colors
A: Blue
Discoverer
RIZ 3
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7
Size Comparison
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8
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9
Spectral Classification
10
Hertzsprung-Russell Diagram
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11
Stellar Lifecycle
12
Blackbody Spectrum
13
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
14
Stellar Fusion
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15Stellar Notes
Doubtful member of the Sco-Cen cluster; lower Cen group of Sco-Cen assoc.
16
Light Travel Time Machine
17
Relativistic Travel
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
NGC 4785
Barred spiral galaxy
Galaxy
mag 12.09
4.4°
Centaurus
NGC 4230
Open cluster
Open Cluster
mag 9.0
5.3°
Centaurus
Mu Cru
Mu Cru (BS4898)
Easy double, sep 34.5″
Double Star
mag 4.03
8.0°
Crux
Blue planetary
NGC 3918
Small bright planetary nebula
Planetary Nebula
mag 8.0
8.9°
Centaurus
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