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Sigma Ori

HIP 26549; Sigma Ori; 48 Ori DoubleStar Ori Visible Level 5 Expert level - Requires steady seeing
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Physical Properties

Magnitude 3.81
Spectral Type O9.5V
Star Color Blue (B-V -0.24)
Distance 950.3 ly

Position & Identifiers

RA 05h 38m 44.8s
Dec -02° 36' 00.0"
Constellation Ori
HR 1931
HIP 26549
Bayer Sigma
Flamsteed 48 Ori
Double Cat 4241

Visibility

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Multiple Star System

Components 5
Component IDs AB
Separation 0.3″
Companion Mag 5.3
Companion Sp B?
Position Angle 239°
Star Colors A: Blue B: Blue
Discoverer BU 1032

Eyepiece View

80x Dawes: 1.9″ TFOV: 0.6°
Realistic = true angular size
N E 239° A (3.8) B (5.3)

Sep: 0.3″ · PA: 239° · N up, E left

Unresolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 3.1″

Size Comparison

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Stellar Lifecycle

Spectral Classification

Hertzsprung-Russell Diagram

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Blackbody Spectrum

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

Stellar Notes

AB 4.1 O9.5V, 5.1 B0.5V, 170y, a = 0.247". Combined mag. and colors. C, 8.79V, A2V at 11" may be physical; D, 6.62V, | -0.20(B-V), B2V, at 13" and E = HR 1932, at 42" CPM with A. A multiple system similar to trapezium. ADS 4241 possibly | the most massive visual binary known, 35 solar masses.
Ori OB1b1; Orion belt; HII reg.; IC 434; a trapezium system.
Hydrogen deficient. Interstellar Lyman alpha absorption observed by AEROBEE rocket.
0.003".

Survey Image

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