Theta Ori
HIP 26235; Theta2 Ori; 43 Ori
Observable Double Star
Excellent (63/100)
Sep: 52.3", Companion: mag 6.2
HIP 26235; Theta2 Ori; 43 Ori
DoubleStar
Ori
Visible
Level 1
Naked eye / Binoculars - Requires steady seeing
Physical Properties
Magnitude
5.08
Spectral Type
O9.5Vp
Star Color
Blue-white
(B-V -0.09)
Position & Identifiers
RA
05h 35m 22.9s
Dec
-05° 24' 58.0"
Constellation
Ori
HR
1897
HIP
26235
Bayer
Theta2
Flamsteed
43 Ori
Double Cat
4188
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Visibility
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Multiple Star System
Components
12
Component IDs
*
Separation
52.3″
Companion Mag
6.2
Companion Sp
B3
Position Angle
93°
Star Colors
A: Blue-white
B: Blue
Discoverer
STFA 16
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
Sep: 52.3″ · PA: 93° · N up, E left
Resolved · 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
5.05 - 5.19V. Component B is NSV 2326, 6.38 - 6.44V.
ADS 4188AB fixed at 52". B is 6.38V, -0.05(B-V), -0.93(U-B), B0.5V; vsini 17k/s. See HR 1893.
ADS 4188A, 20.96722d, K 90.5k/s, V0 +32.1k/s, asini 25.6. Primary 20 solar masses, secondary over 14 solar. | Possibly the counterpart of X-ray binary 3U0527-05 with perhaps collapsed components.
Abnormal reddening at 1500A.
Ori OB1d; sword of Orion; M42; HII region.
Emission is nebular, to red of H beta.
Survey Image
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