Rasalhague
| catalogues and names | Rasalhague, a Oph, NSV 09189, 55 Oph, HR 6556, HD 159561, SAO 102932, FK5: 656 |
| other names | Ras Alhague |
| constellation | Ophiuchus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | RASALHAGUE; Ras Alhague. |
position, motion, parallax:
| position (J2000) | RA: 17h 34min 56,1sec | DEC: +12° 33' 36'' |
| position (J1900) | RA: 17h 30min 17,5sec | DEC: +12° 37' 58'' |
| proper motion (J2000) | RA: 0,12 arcsec/a | DEC: -0,226 arcsec/a |
| radial velocity | 13 km/s note: spectroscopic binaries |
|
| rotational velocity | 219 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,067 arcsec | |
magnitude
| visual magnitude | 2,08 (V on UBV Johnson system) |
spectral / color information
| spectral class | A5III |
| B-V-magnitude | 0,15 |
| U-B-magnitude | 0,1 |
| R-I-magnitude | 0,08 |
| note (category: spectra): | Interstellar CaII lines indicate a cloud of about 1 pc depth in front of Alpha Oph. |
variability information
| variable star identification | 9189 |
| note (category: variability): | Delta Sct? |
double/multiple star system information
| separation | 0,1 arcsec |
| note | astrometric binary |
| note (category: double and multiple data): | A* 2.08 A5III, 8.5y, a = 0.065". Resolved by speckle interferometry. |
miscellaneous information
| note (category: group membership): | UMa stream; Sirius group. |
| note (category: stellar radii or diameters): | Diam. = 0.00153 - 0.00163". |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 17h 34min 56,076sec | DEC: +12° 33' 36,14'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: 0,0082 arcsec/a | DEC: -0,226 arcsec/a | source: 25 | |
| radial velocity | 13 km/s | source: 25 | ||
| trigonometric parallax | 0,065 | ±0,006 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 35,9° | latitude: 22,57° | ||
| GCI unit vector (J2000) | X: -0,106538 | Y: -0,970237 | Z: 0,217463 | |
magnitude:
| visual | 2,08 (observed) | source: 25 |
| photovisual | 2,1 | source: 2 |
spectral information:
| spectral class | A5 | source: 96 | |
| Morgan-Keenan | A5III | source: 25 | |
| B-magnitude | 2,23 ±0,05 | B-V-magnitude | 0,15 |
| U-magnitude | 2,33 ±0,05 | U-B-magnitude | 0,1 |
double/multiple star system information:
| separation between brightest and second brightest component | 0,1 arcsec |
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 | |
| 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 | |
| 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: 17h 32min 36,696sec | DEC: +12° 35' 41,92'' | ±0,003 arcsec |
| position (J2000) | RA: 17h 34min 56,075sec | DEC: +12° 33' 36,21'' | |
| proper motion J1950 (FK4) | RA: 0,008 arcsec/a | DEC: -0,227 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0082 arcsec/a | DEC: -0,226 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 2,1 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | A5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 656 |
| Durchmusterung | BD+12 3252 |
| Boss General Catalogue | 23837 |
| Henry Draper Catalogue | 159561 |
data from Combined General Catalogue of Variable Stars (suspected variables) (Kholopov+ 1998)
position:
| position (J1950) | RA: 17h 32min 36,7sec | DEC: +12° 35' 42'' |
variability informations:
| magnitute at max. brightness | 2,02 |
| magnitute at min. brightness | 2,13 |
| photometric system | visual, photovisual or Johnson's V |
spectral information
| spectral class | A5 |
references
| to a study | 140098D (designation: ALPHA OPH) |
miscanellous
| There are notes in the published catalog (Kukarkin et al.(1982)). |