Unukalhai
| catalogues and names | Unukalhai, a Ser, NSV 20391, 24 Ser, HR 5854, HD 140573, SAO 121157, FK5: 582, WDS 15443+0626A |
| other names | Unuk al Hay, Unuk Elhaia, Unuk, Unukalhay, Cor Serpentis |
| constellation | Serpens |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | UNUKALHAI; Unuk al Hay; Unuk Elhaia; Unuk; Unukalhay; Cor Serpentis. |
position, motion, parallax:
| position (J2000) | RA: 15h 44min 16,1sec | DEC: +6° 25' 32'' |
| position (J1900) | RA: 15h 39min 20,5sec | DEC: +6° 44' 25'' |
| proper motion (J2000) | RA: 0,137 arcsec/a | DEC: 0,047 arcsec/a |
| radial velocity | 3 km/s note: suspected variable radial velocity |
|
| rotational velocity | <17 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,053 arcsec | |
magnitude
| visual magnitude | 2,65 (V on UBV Johnson system) |
spectral / color information
| spectral class | K2IIIbCN1 |
| B-V-magnitude | 1,17 |
| U-B-magnitude | 1,24 |
| R-I-magnitude | 0,56 |
double/multiple star system information
| number of components of multiple star system | 3 |
| separation | 58,2 arcsec |
| mag difference (of double or brightest multiple) | 8,3 |
| component ID | AB |
| note (category: double and multiple data): | SR? Amp. 0.2V. ADS 9765B, optical. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 15h 44min 16,087sec | DEC: +6° 25' 32,31'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: 0,0092 arcsec/a | DEC: 0,047 arcsec/a | source: 25 | |
| radial velocity | 3 km/s | source: 25 | ||
| trigonometric parallax | 0,053 | ±0,005 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 14,2° | latitude: 44,08° | ||
| GCI unit vector (J2000) | X: -0,554716 | Y: -0,824479 | Z: 0,111914 | |
magnitude:
| visual | 2,65 (observed) | source: 25 |
| photovisual | 2,8 | source: 2 |
spectral information:
| spectral class | K0 | source: 96 | |
| Morgan-Keenan | K2IIIbCN1 | source: 25 | |
| B-magnitude | 3,82 ±0,05 | B-V-magnitude | 1,17 |
| U-magnitude | 5,06 ±0,05 | U-B-magnitude | 1,24 |
double/multiple star system information:
| separation between brightest and second brightest component | 58,2 arcsec |
| magnitude difference between brightest and second brightest component | 9,1 |
| position angle | 350 ° |
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 | |
| 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: 15h 41min 48,151sec | DEC: +6° 34' 53,93'' | ±0,003 arcsec |
| position (J2000) | RA: 15h 44min 16,092sec | DEC: +6° 25' 32,34'' | |
| proper motion J1950 (FK4) | RA: 0,0091 arcsec/a | DEC: 0,044 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0092 arcsec/a | DEC: 0,047 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 2,8 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | K0 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 582 |
| Durchmusterung | BD+06 3088 |
| Boss General Catalogue | 21158 |
| Henry Draper Catalogue | 140573 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 15h 44,3min | DEC: +6° 26' |
| proper motion (J2000) | RA: 0,137 arcsec/a | DEC: 0,047 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 | 1836 | 8 | 360° | 61,5'' | 2,65 | 11,8 | K2III | HJ 1277 |
| 1911 | 350° | 58,2'' | ||||||
| AC | 1836 | 2 | 271° | 112,7'' | 2,65 | 13 | - | HJ 1277 |
| 1960 | 268° | 136,1'' |
discoverer information:
| discoverer code | discoverer | reference |
| HJ 1277 | Herschel, J. | - |
notes:
| note | Alpha Ser. Variable? |