d Cephei

The object was found in the following catalogues:
  1. The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

  2. SKY2000 - Master Star Catalog

  3. Smithsonian Astrophysical Observatory Star Catalog

  4. The Washington Visual Double Star Catalog, 1996.0

  5. Combined General Catalogue of Variable Stars (Vol. I-III)

catalogues and names d Cep, del Cep, 27 Cep, HR 8571, HD 213306, SAO 34508, FK5: 847, WDS 22292+5825A
constellation Cepheus

data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)

object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

position, motion, parallax:

position (J2000) RA: 22h 29min 10,3sec DEC: +58 24' 55''
position (J1900) RA: 22h 25min 27,3sec DEC: +57 54' 12''
proper motion (J2000) RA: 0,015 arcsec/a DEC: 0,001 arcsec/a
radial velocity -15 km/s
note: spectroscopic binaries
rotational velocity 9 km/s (uncertain) (variable)
trigonometric parallax 0,011 arcsec


visual magnitude 3,75
(V on UBV Johnson system)

spectral / color information

spectral class F5Ib-G2Ib
B-V-magnitude 0,6
R-I-magnitude 0,4

variability information

variable star identification Del Cep
note (category: variability): 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.

double/multiple star system information

number of components of multiple star system 3
separation 40,8 arcsec
mag difference (of double or brightest multiple) 2,4
component ID AC
note (category: double and multiple data): 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.
note (category: spectroscopic binaries): 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.

data from SKY2000 - Master Star Catalog (Myers+ 1997)

position, motion, parallax:

position (J2000) RA: 22h 29min 10,266sec DEC: +58 24' 54,62'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,0019 arcsec/a DEC: 0,001 arcsec/a source: 25
radial velocity -15 km/s source: 25
trigonometric parallax 0,011 0,001 arcsec source: 25
galactic coord. (B1950) longitude: 105,2 latitude: 0,53
GCI unit vector (J2000) X: 0,483163 Y: -0,202183 Z: 0,851866


visual 3,5 (observed) source: 31

spectral information:

spectral class G0 source: 96
Morgan-Keenan F5Ib-G2Ib source: 25
B-magnitude 4,35 0,05 B-V-magnitude 0,6
U-magnitude 4,4 0,02 U-B-magnitude 0,36

variability information:

source of data: 30
variability type 111
var. amplitude 0,89
var. period 5,37
var. epoch 2436075
24. August 1957, 12:00:00 UT
next max light 2451621,15
17. March 2000, 15:36:00 UT

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 21 arcsec
position angle 284

component magnitude spectral class catalogue(s)/name(s)
A 3,5 G0 d Cephei, 27 Cep, HR 8571, HD 213306, SAO 34508
B 6,3 A0


15 FK5, FK5 Extension and FK5 Supplement
Fricke, W., H. Schwan and T. Lederle, "Fifth Fundamental Catalogue (FK5), Part I. The Basic Fundamental Stars," Veroff. Astronomisches Recheninstitut, No. 32, Heidelberg, Germany, 1988, and Fricke, W., H. Schwan, and T.E. Corbin, "Fifth Fundamental Catalogue (FK5), Part II. The FK5 Extension," Veröff. Astronomisches Recheninstitut, No. 33, Heidelberg, Germany, 1991
19 WDS Catalog
Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996
25 Bright Star Catalogue, 5th edition
Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994
30 GCVS, 4th edition
Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88
31 CRM' (non-GCVS variable data)
Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 1994
96 SAO or HD/HDE Catalog
Reference from Value 1 or Reference from Value 2

data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)

position and proper motion:

position (J1950) RA: 22h 27min 18,529sec DEC: +58 9' 31,76'' 0,004 arcsec
position (J2000) RA: 22h 29min 10,255sec DEC: +58 24' 54,52''
proper motion J1950 (FK4) RA: 0,0015 arcsec/a DEC: 0,005 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0018 arcsec/a DEC: 0 arcsec/a
source of proper motion data Determined by source catalog


visual 4 (accuracy: 2 decimals)
source of visual magnitude data Arithmetic mean of maximum and minimum magnitudes of a variable star

spectral information:

spectral class +++
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Variable star in visual magnitude in source catalog


source catalogue FK4, catalogue number: 847
Durchmusterung BD+57 2548
Boss General Catalogue 31421
Henry Draper Catalogue 213306

data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

position and proper motion:

position (J2000) RA: 22h 29,2min DEC: +58 25'
proper motion (J2000) RA: 0,015 arcsec/a DEC: 0,001 arcsec/a

double/multiple star system information:

component year number of measures position angle angular separation magnitude of 1st component magnitude of 2nd component spectral class(es) discoverer code
AB 1878 6 286 19,4'' - 13 F5Iab BU 702
1961 284 21''
AC 1835 33 191 40,8'' - 6,3 B7V STF 58

discoverer information:

discoverer code discoverer reference
BU 702 Burnham, S.W. -
STF 58 Struve, F.G.W. -


note Delta Cep. Prototype of the Cepheid variables, P = 5.36d. C is variable and a spectroscopic binary.

data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)


position (J1950) RA: 22h 27min 18,5sec DEC: +58 9' 32''

variability informations:

variability type DCEP pulsating variable star
magnitute at max. brightness 3,48
magnitute at min. brightness 4,37
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2436075,445
24. August 1957, 22:40:48 UT
period [d] 5,366341
next maximum light [JD] 2451621,734877
18. March 2000, 05:38:13 UT
rising time 25 % of period

spectral information

spectral class F5Ib-G1Ib


to a study Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph Vol. I GCVS (see Kholopov et al. 1985-1988)


ID in the GCVS catalogue 20/9004
constellation Cepheus
notes on existence The star is equivalent to '0209005 eps'.
There are notes in published catalog.

variability type description

variability type description
DCEP These are the classical cepheids, or Delta Cep-type variables. Comparatively young objects that have left the main sequence and evolved into the instability strip of the Hertzsprung-Russell (H-R) diagram, they obey the well-known Cepheid period-luminosity relation and belong to the young disk population. DCEP stars are present in open clusters. They display a certain relation between the shapes of their light curves and their periods.