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Alpheratz

HIP 677; Alpha And; 21 And

HIP 677; Alpha And; 21 And DoubleStar And Visible Level 3 Medium telescope (6-8") - Requires steady seeing
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Physical Properties

Magnitude 2.06
Variable Type Alpha2 CVn (Magnetic Rotating)
Spectral Type B5.5V
Star Color Blue-white (B-V -0.11)
Distance 101.9 ly

Position & Identifiers

RA 00h 08m 23.3s
Dec +29° 05' 26.0"
Constellation And
HR 15
HIP 677
Bayer Alpha
Flamsteed 21 And
Variable ID Alp And
Double Cat 94

Visibility

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Multiple Star System

Separation 92.8″
Companion Mag 11.1
Position Angle 286°
Star Colors A: Blue-white B: Yellow-white
Discoverer H 5 32

Eyepiece View

80x Dawes: 1.9″ TFOV: 0.6°
Realistic = true angular size
N E 286° A (2.1) B (11.1)

Sep: 92.8″ · PA: 286° · N up, E left

Resolved · 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

Alpha CV 2.02 - 2.06V, 0.9636 or 0.966222d. Some spectral lines vary same period, others half period, some nonvariable.
ADS 94A, 96.6960d, K 30.8k/s, V0 -11.6k/s, asini 34.2.
Pleiades group.
Gallium II lines strong. HgMn star. Spectrum appears earlier at shorter wavelengths.
ALPHERATZ; Alpherat; Sirrah; Sirah. Also formerly called Delta Peg.
Radius 5 solar.

Survey Image

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