Garnet Star
| catalogues and names | Garnet Star, m Cep, mu Cep, HR 8316, HD 206936, SAO 33693, WDS 21435+5847A |
| constellation | Cepheus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Herschel's "Garnet Star". Both Bayer (1603) and Argelander (1843) showed Mu Cep in the position of 14 Cep = HR |
position, motion, parallax:
| position (J2000) | RA: 21h 43min 30,4sec | DEC: +58° 46' 48'' |
| position (J1900) | RA: 21h 40min 26,8sec | DEC: +58° 19' 17'' |
| proper motion (J2000) | RA: 0,003 arcsec/a | DEC: -0,003 arcsec/a |
| radial velocity | 19 km/s note: variable radial velocity |
|
| trigonometric parallax | 0,003 arcsec | |
magnitude
| visual magnitude | 4,08 (V on UBV Johnson system) |
spectral / color information
| spectral class | M2-Ia |
| B-V-magnitude | 2,35 |
| U-B-magnitude | 2,42 |
| R-I-magnitude | 1,76 |
| note (category: colors): | Large infrared excess. |
variability information
| variable star identification | Mu Cep |
double/multiple star system information
| number of components of multiple star system | 3 |
| separation | 19,5 arcsec |
| mag difference (of double or brightest multiple) | 8,3 |
| component ID | AB |
miscellaneous information
| note (category: group membership): | Cep OB2. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 21h 43min 30,473sec | DEC: +58° 46' 48,75'' | ±0,35 arcsec | source: 17 |
| proper motion (J2000) | RA: 0,0007 arcsec/a | DEC: 0,003 arcsec/a | source: 25 | |
| radial velocity | 19 km/s | source: 25 | ||
| trigonometric parallax | 0,003 | - | source: 25 | |
| galactic coord. (B1950) | longitude: 100,6° | latitude: 4,32° | ||
| GCI unit vector (J2000) | X: 0,429085 | Y: -0,290764 | Z: 0,855185 | |
magnitude:
| visual | 3,4 (observed) | source: 31 |
| photographic | 6,5 | source: 16 |
spectral information:
| spectral class | M0 | source: 96 | |
| Morgan-Keenan | M2-Ia | source: 25 | |
| B-magnitude | 6,43 ±0,05 | B-V-magnitude | 2,35 |
| U-magnitude | 8,85 ±0,05 | U-B-magnitude | 2,42 |
variability information:
| variability type | 192 |
| var. amplitude | 1,7 |
| var. period | 730 |
double/multiple star system information:
| separation between brightest and second brightest component | 19,5 arcsec |
| position angle | 260 ° |
sources:
| 16 | PPM North and PPM South Catalogs and PPM Supplement |
| Roser, S., and U. Bastian, "Catalogue of Positions and Proper Motions," A&AS, Vol. 74, p. 449, 1988, and Bastian, U., et al., "Catalogue of Positions and Proper Motions - South," 1993 | |
| 17 | ACRS |
| Corbin, T.E., and S.E. Urban, Astrographic Catalog Reference Stars, United States Naval Observatory, 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: 21h 41min 58,501sec | DEC: +58° 33' 0,65'' | ±0,026 arcsec |
| position (J2000) | RA: 21h 43min 30,441sec | DEC: +58° 46' 48,1'' | |
| proper motion J1950 (FK4) | RA: 0 arcsec/a | DEC: 0,001 arcsec/a | ±0,005 arcsec/a in RA ±0,004 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0004 arcsec/a | DEC: -0,003 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | M0 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Both double and variable, in either visual or photographic magnitudes |
catalogues
| source catalogue | GC, catalogue number: 30440 |
| Durchmusterung | BD+58 2316 |
| Boss General Catalogue | 30440 |
| Henry Draper Catalogue | 206936 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 21h 43,5min | DEC: +58° 47' |
| proper motion (J2000) | RA: 0,005 arcsec/a | DEC: 0,003 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 | 9 | 260° | 19,5'' | - | 12,3 | M2Iae | BU 690 |
| AC | 1878 | 6 | 299° | 41,2'' | - | 12,7 | - | BU 690 |
discoverer information:
| discoverer code | discoverer | reference |
| BU 690 | Burnham, S.W. | - |
notes:
| note | Mu Cep. A is a semiregular variable. |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 22h 21min 48sec | DEC: +57° 25' 42'' | ± 1 sec / ± 0.1 arcmin |
variability informations:
| variability type | CEP | pulsating variable star |
| magnitute at max. brightness | 12,7 | |
| magnitute at min. brightness | 14,1 | |
| photometric system | photographic magnitudes | |
| epoch for maximum light [JD] | 2433541,653 17. September 1950, 03:40:19 UT |
|
| period [d] | 3,76782 | |
| next maximum light [JD] | 2451623,42118 19. March 2000, 22:06:30 UT |
|
| rising time | 33 % of period |
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 | 20/283 |
| constellation | Cepheus |
| notes on existence | The star is equivalent to '0200284 MV'. |
variability type description
| variability type | description |
| CEP | Cepheids. Radially pulsating, high luminosity (classes Ib-II) variables with periods in the range of 1-135 days and amplitudes from several hundredths to 2 mag in V (in the B band, the amplitudes are greater). Spectral type at maximum light is F; at minimum, the types are G-K. The longer the period of light variation,the later is the spectral type. The maximum of the surface-layer expansion velocity almost coinciding with maximum light. |