Rasalhague
HIP 86032; Alpha Oph; 55 Oph
HIP 86032; Alpha Oph; 55 Oph
DoubleStar
Oph
Visible
Level 5
Expert level - Requires steady seeing
Physical Properties
Magnitude
2.08
Variable Type
Delta Scuti (Pulsating)
Spectral Type
A5IVnn
Star Color
Yellow-white
(B-V 0.15)
Distance
48.7 ly
Position & Identifiers
RA
17h 34m 56.1s
Dec
+12° 33' 36.0"
Constellation
Oph
HR
6556
HIP
86032
Bayer
Alpha
Flamsteed
55 Oph
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Visibility
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Multiple Star System
Separation
0.7″
Companion Mag
5.0
Position Angle
248°
Star Colors
A: Yellow-white
Discoverer
MCY 4
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
Sep: 0.7″ · PA: 248° · N up, E left
Unresolved · 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
Delta Sct?
A* 2.08 A5III, 8.5y, a = 0.065". Resolved by speckle interferometry.
UMa stream; Sirius group.
Interstellar CaII lines indicate a cloud of about 1 pc depth in front of Alpha Oph.
RASALHAGUE; Ras Alhague.
Diam. = 0.00153 - 0.00163".
Survey Image
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