U Ophiuchi — Variable Star in Ophiuchus
Excellent (66/100)
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1Physical Properties
Magnitude
5.88
Range
5.84 - 6.56
Period
40.3 hours
Variable Type
Eclipsing Binary (Algol-type)
Spectral Type
B5Vnn+B5V
Star Color
Blue
(B-V 0.06)
Distance
1,631 ly
2Position & Identifiers
RA
17h 16m 31.7s
Dec
+01° 12' 38.0"
Constellation
Ophiuchus
(Oph)
HR
6414
HIP
84500
HD
156247
SAO
122226
Variable ID
U Oph
Double Cat
10428
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3How easy to follow?
Magnitude
5.8 – 6.6 mag
Amplitude
0.7 mag
Period
1.68 d
Type
EA/DM
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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
May – Jul
(peak: Jun)
5Survey Image
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6Light Curve
7Comparison Stars for U Oph (5.8–6.6)
Nearby stable stars for estimating brightness (AAVSO)
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8
Size Comparison
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9
Compare Stars
10
Spectral Classification
11
Hertzsprung-Russell Diagram
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12
Stellar Lifecycle
13
Blackbody Spectrum
14
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
15
Stellar Fusion
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16Stellar Notes
ADS 10428A, EA 5.84 - 6.56V, 1.67734617d. Period changes. i 86.57d. Components 5.3 and 4.6 Suns.
B is dG0, optical.
ADS 10428A, B2, A0-2, 1.6773d, K 180.0k/s, V0 -10.8k/s, msin3i 5.00, asini 4.15. vsini secondary 92k/s.
17
Light Travel Time Machine
18
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.
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Article
Ophiuchus
Mythology, bright stars, and deep-sky highlights.
Constellation
