For the variable star type, see Delta Cephei variable. For the general class of variable stars, see Cepheid variable.
Delta Cephei
Location of δ Cep (circled)
Observation data Epoch J2000.0 Equinox J2000.0
Constellation
Cepheus
δ Cep A
Right ascension
22h 29m 10.26502s[1]
Declination
+58° 24′ 54.7139″[1]
Apparent magnitude (V)
4.07 (3.48–4.37) / 7.5
δ Cep C
Right ascension
22h 29m 09.248s[1]
Declination
+58° 24′ 14.76″[1]
Apparent magnitude (V)
6.3
Characteristics
Spectral type
F5Ib-G1Ib[2] + B7-8[3]
U−B color index
0.36
B−V color index
0.60
Variable type
Cepheid
Astrometry
Radial velocity (Rv)
-16.8[4] km/s
Proper motion (μ)
RA: +15.35[1] mas/yr Dec.: +3.52[1] mas/yr
Parallax (π)
3.77 ± 0.16 mas[1]
Distance
887 ± 26 ly (272 ± 8[5][6] pc)
Absolute magnitude (MV)
–3.47 ± 0.10(–3.94 - –3.05)[5]
Details
δ Cep A
Mass
4.5 ± 0.3[7]M☉
Radius
46.1+1.9 −2.1[8]R☉
Luminosity
~2000[7]L☉
Surface gravity (log g)
1.65[8] cgs
Temperature
5,864[8] K
Metallicity [Fe/H]
+0.08[9] dex
Rotational velocity (v sin i)
9[10] km/s
δ Cep B[4]
Mass
0.2 - 1.2 M☉
δ Cep C
Luminosity
500 L☉
Temperature
8,800[7] K
Orbit[4]
Primary
δ Cep A
Companion
δ Cep B
Period (P)
6.03 yr
Eccentricity (e)
0.647
Semi-amplitude (K1) (primary)
1.509 ± 0.2 km/s
Other designations
27 Cephei, BD+57 2548, FK5 847, HD 213306, HIP 110991, HR 8571, SAO 34508.
Database references
SIMBAD
data
Delta Cephei (δ Cep, δ Cephei) is a quadruple star system[4] located approximately 887 light-years away in the northern constellation of Cepheus, the King. At this distance, the visual magnitude of the star is diminished by 0.23 as a result of extinction caused by gas and dust along the line of sight.[5] It is the prototype of the Cepheid variable stars that undergo periodic changes in luminosity.
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DeltaCephei (δ Cep, δ Cephei) is a quadruple star system located approximately 887 light-years away in the northern constellation of Cepheus, the King...
Cepheids such as RS Puppis and Polaris. The term Cepheid originates from DeltaCephei in the constellation Cepheus, identified by John Goodricke in 1784. It...
rapid rise to maximum light followed by a slower fall to minimum (e.g. DeltaCephei). This is due to the phase difference between the radius and temperature...
estimated mass of 1,937 M☉, of which about 24% is interstellar matter. A DeltaCephei type variable star designated U Sagittarii is a member of this cluster...
1786, ten variable stars were known. John Goodricke himself discovered DeltaCephei and Beta Lyrae. Since 1850, the number of known variable stars has increased...
asterism consisting of α Cephei, 4 Cephei, HD 194298, Eta Cephei, Theta Cephei, Xi Cephei, 26 Cephei, Iota Cephei and Omicron Cephei. Consequently, the Chinese...
with Cepheid variables, which are named after DeltaCephei and are luminous supergiant stars. Beta Cephei variables are somewhat evolved stars of masses...
Hubble Space Telescope: A Parallax of the Fundamental Distance Calibrator deltaCephei". The Astronomical Journal. 124 (3): 1695–1705. arXiv:astro-ph/0206214...
Serpentis Binary star system 3.53 Delta Geminorum Triple star system 3.54 Iota Cephei Star 3.54 Xi Hydrae Star 3.54 Delta Eridani Star Suspected variable...
Airport, IATA code KUI, on Kawau Island KUI 91AB, a variable star of DeltaCephei type KUI 93AB, an eclipsing binary of Algol variable type Kui (Chinese...
DeltaCephei (itself the prototype) and Polaris are Cepheid variables and yellow supergiants. Antares and VV Cephei A are red supergiants. μ Cephei is...
Viking. p. 113. ISBN 9780698148697. Malatesta, Kerri (April 13, 2010). "DeltaCephei". American Association of Variable Star Observers. Retrieved January...
variable", later called a Cepheid variable after the prototype star DeltaCephei, showed a definite relationship between the variability period and the...
Sirius Mira, a variable consisting of a red giant and a white dwarf DeltaCephei, a Cepheid variable Almaaz, an eclipsing binary Spica Alpha Centauri...
Leporis, Alpha Persei, Delta Canis Majoris and Iota¹ Scorpii. Many of them are variable stars, mostly pulsating Cepheids such as δ Cephei itself. Yellow supergiants...
October 19 – John Goodricke begins his observations of the variable star DeltaCephei from York. Publication of the Annals of Agriculture edited by Arthur...
Cephei ("Errai") by 3000 AD, with Errai reaching its closest alignment with the northern celestial pole around 4200 AD. Iota Cephei and Beta Cephei will...
Astrophysical Observatory DCEP – (celestial object) DeltaCEPhei, a class of Cepheids named after DeltaCephei, the archetype for the class DDEB – (celestial...
that ranges from 3.49 to 4.3 over a period of 7.177 days. Along with DeltaCephei, Zeta Geminorum and Beta Doradus, it is one of the most prominent naked...
in the northern constellation of Cygnus, abbreviated X Cyg. This is a DeltaCephei variable that ranges in brightness from an apparent visual magnitude...
amplitudes, such as the classical Cepheids, RR Lyrae stars and large-amplitude Delta Scuti stars show regular light curves. This regular behavior is in contrast...
hue. Delta Crucis is a strong candidate Beta Cephei variable. Its rotation is very fast, with a projected rotational velocity of 210 km s−1. Delta Crucis...
spectroscopic search for nonradial pulsations in the Delta Scuti stars Delta Delphini and Epsilon Cephei", Astronomy and Astrophysics, 269 (1–2): 195–200...
Krüger 60 (DO Cephei) is a binary star system located 13.1 light-years (4.0 parsecs) from the Sun. These red dwarf stars orbit each other every 44.6 years...
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