X Ophiuchi — Variable Star in Ophiuchus
Excellent (74/100)
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1Physical Properties
Magnitude
6.40
Range
5.9 - 8.6
Period
329 days
Variable Type
Mira (Long-period Pulsating)
Spectral Type
M6IIIe+K1III
bright giant
Star Color
Red
(B-V 1.32)
Distance
297 ly
2Position & Identifiers
RA
18h 38m 21.0s
Dec
+08° 50' 02.0"
Constellation
Ophiuchus
(Oph)
HR
7002
HIP
91389
HD
172171
SAO
123744
Variable ID
X Oph
Double Cat
11524
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3How easy to follow?
Magnitude
5.9 – 9.2 mag
Amplitude
3.3 mag
Period
329 d
Type
M
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Imp. | Imp. | Imp. |
| 50 mm finder 50mm finder | Medium | Medium | Hard+ |
| 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
May – Jul
(peak: Jun)
5Survey Image
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6Light Curve
7Comparison Stars for X Oph (5.9–9.2)
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 11524A, M 5.9 - 9.2v, 334.39d.
Var. MBE+K1III, 8.8, 485.3y, a = 0.34". Masses A, 15.9; B, 5.0 solar.
0.002".
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.
IC 4756
Open cluster
Open Cluster
mag 5.0
3.4°
Serpens
NGC 6572
Small bright planetary nebula
Planetary Nebula
mag 9.0
6.8°
Ophiuchus
R Aql
Mira-type variable, range 5.5–12.0
Variable Star
mag 6.09
7.0°
Aquila
FF Aql
Pulsating variable, period 4.5d
Variable Star
mag 5.38
9.8°
Aquila
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