Delta Cep
Observable Variable Star
Excellent (67/100)
Range: 3.5 - 4.4, Period: 5.4d, Type: DCEP
HIP 110991; Delta Cep; 27 Cep
VariableStar
Cep
Visible
Level 1
Naked eye / Binoculars - Monitor brightness changes
Physical Properties
Magnitude
3.75
Range
3.5 - 4.4
Period
5.366 days
Variable Type
Classical Cepheid
Spectral Type
F5Ib
Star Color
Yellow
(B-V 0.60)
Distance
863.3 ly
Position & Identifiers
RA
22h 29m 10.3s
Dec
+58° 24' 55.0"
Constellation
Cep
HR
8571
HIP
110991
Bayer
Delta
Flamsteed
27 Cep
Variable ID
Del Cep
Double Cat
15987
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Visibility
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Light Curve
Comparison Stars for Delta Cep (3.5–4.3)
Nearby stable stars for estimating brightness (AAVSO)
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Multiple Star System
Components
3
Component IDs
AC
Separation
21.5″
Companion Mag
13.0
Companion Sp
B7
Position Angle
282°
Star Colors
A: Yellow
B: Blue-white
Discoverer
BU 702
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
Sep: 21.5″ · PA: 282° · 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
ADS 15987A, CDelta 3.48 - 4.34V, 5.366341d. Period varies. Prototype star Delta Cep, discovered by Goodricke in 1784. | Blue companion ADS 15987C is also var. and SB.
B, 13v at 21" optical. AC CPM, C at 41", 6.30V, -0.03(B-V), -0.35(U-B), B7IV, RV -21k/s, vsini 135k/s.
ADS 15987C, blue star whose secondary may have low mass about 0.1 solar. 0.89986 or 0.46458d, K 8.6 or 8.8k/s, V0 | -16.4k/s.
Survey Image
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