Alkurhah
| catalogues and names | Alkurhah, x Cep, 17 Cep, HR 8417, HD 209790, SAO 19827, WDS 22038+6438A |
| other names | Al Kirdah, Kurhah |
| constellation | Cepheus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Alkurhah; Al Kirdah; Kurhah. |
position, motion, parallax:
| position (J2000) | RA: 22h 3min 47,4sec | DEC: +64° 37' 40'' |
| position (J1900) | RA: 22h 0min 53,7sec | DEC: +64° 8' 26'' |
| proper motion (J2000) | RA: 0,209 arcsec/a | DEC: 0,085 arcsec/a |
| radial velocity | -6 km/s note: spectroscopic binaries, double lined spectra note: orbital data avaible |
|
| rotational velocity | 20 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,032 arcsec | |
| note (category: radial and/or rotational velocities): | Change of 7k/s in 55y needs confirmation. |
| note (category: dynamical parallaxes): | 0.038". |
magnitude
| visual magnitude | 4,29 (V on UBV Johnson system) |
spectral / color information
| spectral class | A3/6Vm |
| B-V-magnitude | 0,34 |
| U-B-magnitude | 0,09 |
| R-I-magnitude | 0,13 |
| note (category: spectra): | K/H/m yield classes A3/F1/F2 respectively. |
double/multiple star system information
| number of components of multiple star system | 3 |
| separation | 7,7 arcsec |
| mag difference (of double or brightest multiple) | 2 |
| component ID | AB |
| note (category: double and multiple data): | AB 4.61 A3m, 6.5 F7V or F3III-IV, 3800y, a = 11.5". Aa, 2.254y, a = 0.073". Component B is HD 209791 = GC 30876, vsini =<25k/s. Component C, 12.7v at 97" optical. |
| note (category: spectroscopic binaries): | ADS 15600A, 810.9d, K 7.1k/s, V0 -10.7k/s, msin3i 0.855, asini 70.3. sep. SB components 0.06". Resolved by speckle interferometry. Mass transfer. Secondary undermassive for its luminosity. vsini both components 20k/s. |
miscellaneous information
| note (category: group membership): | Hyades group. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 22h 3min 47,426sec | DEC: +64° 37' 40,24'' | ±1,24 arcsec | source: 29 |
| proper motion (J2000) | RA: 0,0325 arcsec/a | DEC: 0,085 arcsec/a | source: 25 | |
| radial velocity | -6 km/s | source: 25 | ||
| trigonometric parallax | 0,032 | ±0,003 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 106,16° | latitude: 7,37° | ||
| GCI unit vector (J2000) | X: 0,374581 | Y: -0,208082 | Z: 0,903544 | |
magnitude:
| visual | 4,29 (observed) | source: 25 |
| photovisual | 4,6 | source: 2 |
| photographic | 4,7 | source: 2 |
spectral information:
| spectral class | A3 | source: 29 | |
| Morgan-Keenan | A3/6Vm | source: 25 | |
| B-magnitude | 4,63 ±0,05 | B-V-magnitude | 0,34 |
| U-magnitude | 4,72 ±0,05 | U-B-magnitude | 0,09 |
double/multiple star system information:
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4,29 | A3 | Alkurhah, x Cephei, 17 Cep, HR 8417, HD 209790, SAO 19827 |
| B | 6,44 | A3 |
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 | |
| 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 | |
| 29 | SAOJ2000 |
| SAO on FK5 at J2000, 1989 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (J1950) | RA: 22h 2min 20,44sec | DEC: +64° 23' 1,68'' | ±0,023 arcsec |
| position (J2000) | RA: 22h 3min 47,426sec | DEC: +64° 37' 40,24'' | |
| proper motion J1950 (FK4) | RA: 0,032 arcsec/a | DEC: 0,089 arcsec/a | ±0,003 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0325 arcsec/a | DEC: 0,085 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4,6 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | A3 |
| 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: 30877 |
| Durchmusterung | BD+63 1802A |
| Boss General Catalogue | 30877 |
| Henry Draper Catalogue | 209790 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 22h 3,8min | DEC: +64° 38' |
| proper motion (J2000) | RA: 0,208 arcsec/a | DEC: 0,089 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 |
| Aa | 1975 | 19 | ° | '' | 4,3 | - | A3m | MCA 69 |
| Aa-B | 1831 | often | 289° | 5,6'' | 4,6 | 6,5 | - | STF2863 |
| 1994 | 275° | 8,5'' | ||||||
| Aa-C | 1912 | 2 | 199° | 95,3'' | 4,6 | 12,7 | - | STF2863 |
| 1925 | 200° | 96,8'' |
discoverer information:
| discoverer code | discoverer | reference |
| MCA 69 | McAlister, H.A. | - |
| STF2863 | Struve, F.G.W. | - |
notes:
| note | Xi Cep. The primary is an astrometric and spectroscopic binary resolved by speckle interferometry. P = 2.25yr, a = 0.07", motion direct. A premature orbit has been computed for AB. Mt. Wilson spectrum of B F8s. Proper motion of B +187 +088. Spectrum of A: A3m. |