V1644 Cygni
catalogues and names
| catalogues and names | V1644 Cyg, 29 Cyg, HR 7736, HD 192640, SAO 69678, BD +36 3955, WDS 20145+3648A |
| constellation | Cygnus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 20h 14min 32sec | DEC: +36° 48' 23'' | ||
| position (2000.73) | RA: 20h 14min 34sec | DEC: +36° 48' 31'' | ||
| position (B1900) | RA: 20h 10min 47.3sec | DEC: +36° 29' 59'' | ||
| proper motion (J2000) | RA: 0.068 arcsec/a | DEC: 0.07 arcsec/a | ||
| radial velocity | -17 km/s note: variable radial velocity |
|||
| rotational velocity | 37 km/s (uncertain) (variable) | |||
| trigonometric parallax | 0.036 arcsec | |||
| galactic coordinates | longitude: 74.45° | latitude: 1.17° | ||
magnitude
| visual magnitude | 4.97 (V on UBV Johnson system) |
spectral / color information
| spectral class | A2V |
| B-V-magnitude | 0.14 |
| U-B-magnitude | 0 |
| R-I-magnitude |
variability information
| variable star identification | V1644 Cyg |
| note (category: variability): | Delta Sct 4.94 - 4.97V, 0.031d. Lambda Boo-type star in Delta Sct instability strip. |
double/multiple star system information
| number of components of multiple star system | 5 |
| separation | 212.4 arcsec |
| mag difference (of double or brightest multiple) | 1.6 |
| component ID | AB |
| note | Worley (1978) update of the IDS |
| note (category: double and multiple data): | B is K1III, optical, vsini =<54k/s. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 20h 14min 32.03sec | DEC: +36° 48' 22.53'' | ±0.35 arcsec | source: 17 |
| position (2000.73) | RA: 20h 14min 34sec | DEC: +36° 48' 31'' | JD: 2451810.88 | |
| proper motion (J2000) | RA: 0.0057 arcsec/a | DEC: 0.066 arcsec/a | source: 25 | |
| radial velocity | -17 km/s | source: 25 | ||
| trigonometric parallax | 0.036 arcsec | ±0.004 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 74.45° | latitude: 1.17° | ||
magnitude:
| visual | 4.97 (observed) | source: 25 |
| photovisual | 5 | source: 2 |
| photographic | 5 | source: 16 |
spectral information:
| spectral class | A0 | source: 96 | |
| Morgan-Keenan | A2V | source: 25 | |
| B-magnitude | 5.11 ±0.05 | B-V-magnitude | 0.14 |
| U-magnitude | 5.11 ±0.05 | U-B-magnitude | 0 |
variability information:
| variability type | 10 |
| var. amplitude | 0.03 |
| var. period | 0.03 |
double/multiple star system information:
| separation between brightest and second brightest component | 212.4 arcsec |
| magnitude difference between brightest and second brightest component | 1.6 |
| position angle | 153 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4.97 | A0 | 29 Cyg, HR 7736, HD 192640, SAO 69678 |
| B | 6.567 | K5 |
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 | |
| 17 | ACRS |
| Corbin, T.E., and S.E. Urban, Astrographic Catalog Reference Stars, United States Naval Observatory, 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 | |
| 30 | GCVS, 4th edition |
| Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88 | |
| 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 (B1950) | RA: 20h 12min 39.579sec | DEC: +36° 39' 7.85'' | ±0.016 arcsec |
| position (2000.73) | RA: 20h 14min 34sec | DEC: +36° 48' 28'' | JD: 2451810.88 |
| position (J2000) | RA: 20h 14min 32.027sec | DEC: +36° 48' 22.97'' | |
| proper motion B1950 (FK4) | RA: 0.0054 arcsec/a | DEC: 0.071 arcsec/a | ±0.003 arcsec/a in RA ±0.002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0.0056 arcsec/a | DEC: 0.07 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | A0 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | GC, catalogue number: 28124 |
| Durchmusterung | BD+36 3955 |
| Boss General Catalogue | 28124 |
| Henry Draper Catalogue | 192640 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 20h 14.5min | DEC: +36° 48' |
| proper motion (J2000) | RA: 0.068 arcsec/a | DEC: 0.066 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 | 1881 | 4 | 153° | 212.4'' | 4.97 | 6.6 | A2V | ENG 72 |
| AC | 1887 | 5 | 23° | 225.2'' | 4.97 | 10 | - | ENG 72 |
| 1921 | - | 221.5'' | ||||||
| Aa | 1908 | 3 | 341° | 38.8'' | 4.97 | 12.2 | - | BUP 207 |
| 1960 | 333° | 36.9'' | ||||||
| BD | 1894 | 4 | 120° | 216.5'' | 6.6 | 10.2 | G8III | ENG 72 |
| 1924 | - | 217.2'' |
discoverer information:
| discoverer code | discoverer | reference |
| ENG 72 | Engelmann, R. | - |
| BUP 207 | - | - |
notes:
| note | 29 Cyg. A Delta Scuti-type variable, V1644 Cyg. |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (equinox 1950.0) | RA: 20h 12min 39.6sec | DEC: +36° 39' 8'' |
variability informations:
| variability type | DSCTC | pulsating variable star |
| magnitute at max. brightness | 4.94 | |
| magnitute at min. brightness | 4.97 | |
| photometric system | visual, photovisual or Johnson's V | |
| period [d] | 0.031 |
spectral information
| spectral class | A2V |
references
| to a study | Vol. I GCVS (see Kholopov et al. 1985-1988) |
| to a chart/photograph | no chart is avaible, but the star is contained in the 'Bonner Durchmusterung' |
miscanellous
| ID in the GCVS catalogue | 31/1644 |
| constellation | Cygnus |
| notes on existence | The star is equivalent to '0311645 V1645'. |
variability type description
| variability type | description |
| DSCTC | Variables of the Delta Scuti type. These are pulsating variables of spectral types A0-F5 III-V displaying light amplitudes from 0.003 to 0.9 mag in V (usually several hundredths of a magnitude) and periods from 0.01 to 0.2 days. The shapes of the light curves, periods, and amplitudes usually vary greatly. Radial as well as nonradial pulsations are observed. The variability of some members of this type appears sporadically and sometimes completely ceases, this being a consequence of strong amplitude modulation with the lower value of the amplitude not exceeding 0.001 mag in some cases. The maximum of the surface layer expansion does not lag behind the maximum light for more than 0.1 periods. DSCT stars are representatives of the galactic disk (flat component) and are phenomenologically close to the SX Phe variables. DSCTC Low amplitude group of Delta Sct variables (light amplitude <0.1 mag in V). The majority of this type's representatives are stars of luminosity class V; objects of this subtype generally are representative of the Delta Sct variables in open clusters. |