Alya
catalogues and names | Alya, q1Ser, NSV 11557, 63 Ser, HR 7141, HD 175638, SAO 124068, FK5: 709, WDS 18562+0412A |
other names | Alga |
constellation | Serpens |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
note (category: star names): | Alya; Alga. |
position, motion, parallax:
position (J2000) | RA: 18h 56min 13,2sec | DEC: +4° 12' 13'' |
position (J1900) | RA: 18h 51min 14,9sec | DEC: +4° 4' 24'' |
proper motion (J2000) | RA: 0,049 arcsec/a | DEC: 0,031 arcsec/a |
radial velocity | -46 km/s note: suspected variable radial velocity |
|
rotational velocity | 143 km/s (uncertain) (variable) | |
trigonometric parallax | 0,03 arcsec |
note (category: dynamical parallaxes): | 0.019". |
magnitude
visual magnitude | 4,62 (V on UBV Johnson system) |
spectral / color information
spectral class | A5V |
B-V-magnitude | 0,17 |
U-B-magnitude | 0,09 |
variability information
variable star identification | 11557 |
note (category: variability): | 4.59 - 4.72V. |
double/multiple star system information
number of components of multiple star system | 3 |
separation | 22,2 arcsec |
mag difference (of double or brightest multiple) | 0,4 |
component ID | AB |
note (category: double and multiple data): | Binary with HR 7142. |
miscellaneous information
note (category: group membership): | Hyades group. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
position (J2000) | RA: 18h 56min 13,19sec | DEC: +4° 12' 12,91'' | ±0,06 arcsec | source: 15 |
proper motion (J2000) | RA: 0,0033 arcsec/a | DEC: 0,031 arcsec/a | source: 25 | |
radial velocity | -46 km/s | source: 25 | ||
trigonometric parallax | 0,03 | ±0,003 arcsec | source: 25 | |
galactic coord. (B1950) | longitude: 37,22° | latitude: 0,85° | ||
GCI unit vector (J2000) | X: 0,242199 | Y: -0,967454 | Z: 0,073301 |
magnitude:
visual | 4,61 (observed) | source: 25 |
photovisual | 4,5 | source: 2 |
spectral information:
spectral class | A5 | source: 96 | |
Morgan-Keenan | A5V | source: 25 | |
B-magnitude | 4,77 ±0,05 | B-V-magnitude | 0,16 |
U-magnitude | 4,88 ±0,05 | U-B-magnitude | 0,11 |
double/multiple star system information:
separation between brightest and second brightest component | 22,3 arcsec |
magnitude difference between brightest and second brightest component | 0,36 |
position angle | 104 ° |
component | magnitude | spectral class | catalogue(s)/name(s) |
A | 4,61 | A5 | Alya, q1Serpentis, 63 Ser, HR 7141, HD 175638, SAO 124068 |
B | 4,98 | A5 | q2Serpentis, 63 Ser, HR 7142, HD 175639, SAO 124070 |
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: 18h 53min 43,976sec | DEC: +4° 8' 13,25'' | ±0,004 arcsec |
position (J2000) | RA: 18h 56min 13,192sec | DEC: +4° 12' 12,92'' | |
proper motion J1950 (FK4) | RA: 0,0031 arcsec/a | DEC: 0,032 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
proper motion J2000 (FK5) | RA: 0,0033 arcsec/a | DEC: 0,031 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 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: 709 |
Durchmusterung | BD+04 3916 |
Boss General Catalogue | 25991 |
Henry Draper Catalogue | 175638 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
position (J2000) | RA: 18h 56,2min | DEC: +4° 12' |
proper motion (J2000) | RA: 0,049 arcsec/a | DEC: 0,031 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 | 1822 | often | 104° | 21,6'' | 4,62 | 4,98 | A5V A5Vn | STF2417 |
1984 | - | 22,3'' | ||||||
BC | 1927 | 2 | 56° | 14,1'' | 4,98 | 7,9 | A5Vn | STF2417 |
1954 | 58° | 26'' |
discoverer information:
discoverer code | discoverer | reference |
STF2417 | Struve, F.G.W. | - |
notes:
note | Theta (1) Ser. B is BD+04@3917, Theta (2) Ser. |
data from Combined General Catalogue of Variable Stars (suspected variables) (Kholopov+ 1998)
position:
position (J1950) | RA: 18h 53min 44sec | DEC: +4° 8' 13'' |
variability informations:
magnitute at max. brightness | 4,59 |
magnitute at min. brightness | 4,72 |
photometric system | visual, photovisual or Johnson's V |
spectral information
spectral class | A5 |
references
to a study | 290477D (designation: ZI 1555) |
miscanellous
There are notes in the published catalog (Kukarkin et al.(1982)). |