Diadem
| catalogues and names | Diadem, a Com, NSV 06116, 42 Com, HR 4968, HD 114378, SAO 100443, WDS 13100+1732A |
| constellation | Coma Berenices |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Diadem. |
position, motion, parallax:
| position (J2000) | RA: 13h 9min 59,3sec | DEC: +17° 31' 46'' |
| position (J1900) | RA: 13h 5min 7,4sec | DEC: +18° 3' 30'' |
| proper motion (J2000) | RA: -0,431 arcsec/a | DEC: 0,136 arcsec/a |
| radial velocity | -18 km/s note: suspected variable radial velocity |
|
| rotational velocity | 28 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,054 arcsec | |
| note (category: radial and/or rotational velocities): | Probably blended with HR 4969. |
| note (category: dynamical parallaxes): | 0.058". |
magnitude
| visual magnitude | 5,22 (original HR magnitude) |
spectral / color information
| spectral class | F5V |
| B-V-magnitude | 0,45 |
| U-B-magnitude | -0,06 |
| note (category: spectra): | Spectrum blended with HR 4969. |
variability information
| variable star identification | 6116 |
| note (category: variability): | Var. of combined light with HR 4969 not confirmed, but 90d inclination of orbit indicates eclipses possible. |
double/multiple star system information
| number of components of multiple star system | 3 |
| separation | 0,2 arcsec |
| mag difference (of double or brightest multiple) | 0,1 |
| component ID | AB |
| note (category: double and multiple data): | AB 5.05 F5V, 5.08 F5V, 25.87y, a = 0.662". Colors, spectrum for combined light. Mag. of blended HR 4968, 4969 is 4.32V. ADS 8804A speckle interferometric sep. 0.43" 1978.40, 0.58" 1981.47. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 13h 9min 59,331sec | DEC: +17° 31' 45,92'' | ±0,43 arcsec | source: 16 |
| proper motion (J2000) | RA: -0,0294 arcsec/a | DEC: 0,143 arcsec/a | source: 25 | |
| radial velocity | -18 km/s | source: 25 | ||
| trigonometric parallax | 0,054 | ±0,005 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 327,99° | latitude: 79,49° | ||
| GCI unit vector (J2000) | X: -0,909443 | Y: -0,286697 | Z: 0,301196 | |
magnitude:
| visual | 5,05 (observed) | source: 25 |
| photovisual | 5,2 | source: 2 |
| photographic | 4,6 | source: 16 |
spectral information:
| spectral class | F5 | source: 96 | |
| Morgan-Keenan | F5V | source: 25 | |
| B-magnitude | 5,5 ±0,05 | B-V-magnitude | 0,45 |
| U-magnitude | 5,44 ±0,05 | U-B-magnitude | -0,06 |
double/multiple star system information:
| magnitude difference between brightest and second brightest component | 0 |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 5,05 | F5 | Diadem, a Comae Berenices, 42 Com, HR 4968, HD 114378, SAO 100443 |
| B | 5,08 | F5 | a Comae Berenices, 42 Com, HR 4969, HD 114379, SAO 100443 |
sources:
| 2 | HD and HDE Catalogs |
| Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University | |
| 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 | |
| 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 | |
| 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: 13h 7min 33,321sec | DEC: +17° 47' 36,25'' | ±0,014 arcsec |
| position (J2000) | RA: 13h 9min 59,287sec | DEC: +17° 31' 45,73'' | |
| proper motion J1950 (FK4) | RA: -0,0302 arcsec/a | DEC: 0,131 arcsec/a | ±0,002 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0301 arcsec/a | DEC: 0,136 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4,5 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | F5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Double star in Aitken's Double Star Catalogue (Aitken 1932) |
catalogues
| source catalogue | GC, catalogue number: 17833 |
| Durchmusterung | BD+18 2697 |
| Boss General Catalogue | 17833 |
| Henry Draper Catalogue | 114378 The "SAO Catalog" entry refers to two consecutive HD numbers, the lower of which is given. |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 13h 10min | DEC: +17° 32' |
| proper motion (J2000) | RA: -0,436 arcsec/a | DEC: 0,138 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 | 1827 | often | ° | '' | 5,1 | 5,1 | F6V | STF1728 |
| AB-C | 1851 | 6 | 322° | 135,6'' | 5,2 | 10,2 | - | STF1728 |
| 1923 | 330° | 110,3'' |
discoverer information:
| discoverer code | discoverer | reference |
| STF1728 | Struve, F.G.W. | - |
notes:
| note | Alpha Com. P = 25.8yr., a = 0.668", inclination 90 degrees. |
data from Combined General Catalogue of Variable Stars (suspected variables) (Kholopov+ 1998)
position:
| position (J1950) | RA: 13h 7min 33,3sec | DEC: +17° 47' 36'' |
variability informations:
| magnitute at max. brightness | 4,29 |
| magnitute at min. brightness | 4,35 |
| photometric system | visual, photovisual or Johnson's V |
spectral information
| spectral class | F6 |
references
| to a study | 482315D (designation: 42 COM) |
miscanellous
| There are notes in the published catalog (Kukarkin et al.(1982)). |