BL Orionis — Variable Star in Orion
Good (58/100)
Observe
1Physical Properties
Magnitude
6.24
Range
5.9 - 6.6
Period
154 days
Variable Type
Semi-Regular Variable (Late-type Giant)
Spectral Type
C5II
Star Color
Deep ruby red
(B-V 2.34)
2Position & Identifiers
RA
06h 25m 28.1s
Dec
+14° 43' 19.0"
Constellation
Orion
(Ori)
HR
2308
HIP
30564
HD
44984
Variable ID
BL Ori
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3How easy to follow?
Magnitude
5.9 – 6.6 mag
Amplitude
0.7 mag
Period
153.8 d
Type
SRB
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | V. hard+ | V. hard | Imp. |
| 50 mm finder 50mm finder | Medium | Medium | Medium |
| 150 mm telescope 150mm scope | Medium | Medium | Medium |
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)
5Light Curve
6Comparison Stars for BL Ori (5.9–6.6)
Nearby stable stars for estimating brightness (AAVSO)
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Explore
7
Size Comparison
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8
Compare Stars
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
Discover
15Stellar Notes
Lb 8.5 - 9.7p.
Technetium found in spectrum.
Survey Image
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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 2194
Open cluster
Open Cluster
mag 8.5
3.4°
Orion
Hubble's Variable Nebula
NGC 2261
Reflection nebula around a bright star
Reflection Nebula
mag 10.0
6.9°
Monoceros
T Mon
Pulsating variable, period 27.0d
Variable Star
mag 5.98
7.6°
Monoceros
TV Gem
Variable star, range 6.3–7.5
Variable Star
mag 6.56
7.8°
Gemini
6 Gem
Mira-type variable, range 5.7–8.1
Variable Star
mag 6.39
8.8°
Gemini
3 Gem
Variable star, range 7.0–10.0
Variable Star
mag 5.75
9.2°
Gemini
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