d Cephei
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)
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 |
magnitude
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 |
magnitude:
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:
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:
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 |
sources:
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 |
magnitude:
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 |
catalogues
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. | - |
notes:
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:
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 |
references
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) |
miscanellous
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. |