Theta Orionis — Star in Orion
HIP 26221; Theta1 Orionis; 41 Orionis
Observe
1Physical Properties
Magnitude
5.13
Spectral Type
O6p
Star Color
Blue
(B-V 0.02)
(reddened by dust)
Distance
3,262 ly
2Position & Identifiers
RA
05h 35m 16.5s
Dec
-05° 23' 23.0"
Constellation
Orion
(Ori)
HR
1895
HIP
26221
HD
37022
SAO
132314
Bayer
Theta1
Flamsteed
41 Ori
Double Cat
4186
Querying VizieR catalog...
3How easy to spot?
Sign in
and configure your equipment and default location to see a personalized row.
| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Medium | Hard+ | Hard |
| 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
Set a location in User Settings to see visibility data.
Best season
Nov – Jan
(peak: Dec)
5Survey Image
Loading survey image…
Explore
6
Size Comparison
Querying VizieR for stellar data…
7
Compare Stars
8
Spectral Classification
9
Hertzsprung-Russell Diagram
Loading HR diagram…
10
Stellar Lifecycle
11
Blackbody Spectrum
12
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
13
Stellar Fusion
Discover
14Stellar Notes
5.10 - 5.16V. He II 4686 suggests var. density of infalling material on time scale of days.
See HR 1893. Fixed with HR 1896 at 13".
Inverse P Cyg profile suggests infalling material rather than SB.
Abnormal reddening at 1500A. Color excess E(B-V) = +0.32. Morel and Magenat indicate R-I from -0.13 to 0.00 in | disagreement with other Johnson sources.
Ori OB1d; sword of Orion; a trapezium star. Orion Neb, NGC 1976, HII reg.
Interstellar Lyman alpha absorption observed by AEROBEE rocket. Also classified O6ep, O7Vp, O6.5III.
15
Light Travel Time Machine
16
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.
M42
NGC 1976
Emission nebula — try an OIII filter
Emission Nebula
mag 4.0
0.0°
Orion
Theta Ori
HIP 26235; Theta2 Orionis; 43 Orionis
Easy double, sep 52.3″
Double Star
mag 5.08
0.0°
Orion
NGC 1973
Diffuse nebula
Diffuse Nebula
mag 7.00
0.7°
Orion
NGC 1981
Rich open cluster
Open Cluster
mag 4.6
1.0°
Orion
Upsilon Ori
Hot blue O-type star
Star
mag 4.62
2.1°
Orion
Explore Nightbase
Related knowledge, tools, and stories — no observation planning required.
Arthur Eddington
1919 eclipse expedition confirming general relativity; first theory of stellar interiors; the Eddington limit
Biography
The Hertzsprung-Russell Diagram — Reading Stars Like a Map
The HR diagram turns the night sky into a physics map: every named star has a spot, every spot tells you mass, age, and fate. A guide for amateur observers.
Article
Orion
Mythology, bright stars, and deep-sky highlights.
Constellation
