DT Cygni
catalogues and names
| catalogues and names | DT Cyg, HR 8084, HD 201078, SAO 70917, BD +30 4318, FK5: 3687 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 21h 6min 30.3sec | DEC: +31° 11' 5'' | ||
| position (B1900) | RA: 21h 2min 18.4sec | DEC: +30° 47' 1'' | ||
| proper motion (J2000) | RA: 0.007 arcsec/a | DEC: -0.004 arcsec/a | ||
| radial velocity | 0 km/s note: variable radial velocity |
|||
| rotational velocity | 9 km/s (uncertain) (variable) | |||
| galactic coordinates | longitude: 76.55° | latitude: -10.78° | ||
magnitude
| visual magnitude | 5.82 (V on UBV Johnson system) |
spectral / color information
| spectral class | F7.5Ib-II |
| B-V-magnitude | 0.56 |
| R-I-magnitude | |
| IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
| note (category: spectra): | Also classified F5.5-F7Ib-II. |
variability information
| variable star identification | DT Cyg |
| note (category: variability): | CDelta 5.57 - 5.96V, 2.499215d. Period varies. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 21h 6min 30.236sec | DEC: +31° 11' 4.82'' | ±0.2 arcsec | source: 52 |
| proper motion (J2000) | RA: -0.0001 arcsec/a | DEC: -0.004 arcsec/a | source: 25 | |
| radial velocity | 0 km/s | source: 25 | ||
| galactic coord. (B1950) | longitude: 76.56° | latitude: -10.78° | ||
magnitude:
| visual | 5.6 (observed) | source: 31 |
| photovisual | 5.9 | source: 2 |
| photographic | 6.3 | source: 16 |
spectral information:
| spectral class | F5 | source: 96 | |
| Morgan-Keenan | F7.5Ib-II | source: 25 | |
| B-magnitude | 6.3 ±0.3 | B-V-magnitude | 0.53 |
| U-magnitude | 6.62 ±0.3 | U-B-magnitude | 0.32 |
variability information:
| variability type | 115 |
| var. amplitude | 0.39 |
| var. period | 2.5 |
| var. epoch | 2444047 22. June 1979, 12:00:00 UT |
| next max light | 2452219.5 6. November 2001, 00:00:00 UT |
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 | |
| 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 | |
| 31 | CRM' (non-GCVS variable data) |
| Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 1994 | |
| 52 | PPMN-HP subset |
| PPMN Star Catalogue (Reference 16) High-Precision Subset (Code H) | |
| 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: 21h 4min 24.223sec | DEC: +30° 58' 59.79'' | ±0.02 arcsec |
| position (J2000) | RA: 21h 6min 30.205sec | DEC: +31° 11' 4.9'' | |
| proper motion B1950 (FK4) | RA: -0.0002 arcsec/a | DEC: 0 arcsec/a | ±0.004 arcsec/a in RA ±0.005 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.0001 arcsec/a | DEC: -0.003 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5.7 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | F5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Variable star in visual magnitude in source catalog |
catalogues
| source catalogue | GC, catalogue number: 29502 |
| Durchmusterung | BD+30 4318 |
| Boss General Catalogue | 29502 |
| Henry Draper Catalogue | 201078 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (equinox 1950.0) | RA: 21h 4min 24.2sec | DEC: +30° 59' 0'' |
variability informations:
| variability type | DCEPS | pulsating variable star |
| magnitute at max. brightness | 5.57 | |
| magnitute at min. brightness | 5.96 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2444046.969 22. June 1979, 11:15:22 UT |
|
| period [d] | 2.499215 | |
| next maximum light [JD] | 2452219.40205 5. November 2001, 21:38:57 UT |
|
| rising time | 48 % of period |
spectral information
| spectral class | F5.5-F7Ib-II |
references
| to a study | the main characteristics of the star was determined by the authors themselves |
| to a chart/photograph | Vol. I GCVS (see Kholopov et al. 1985-1988) |
miscanellous
| ID in the GCVS catalogue | 31/142 |
| constellation | Cygnus |
| notes on existence | The star is equivalent to '0310143 DU'. |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| DCEPS | These are Delta Cep variables having light amplitudes <0.5 mag in V (<0.7 mag in B) and almost symmetrical light curves (M-m approx. 0.4 - 0.5 periods); as a rule, their periods do not exceed 7 days. They are probably first-overtone pulsators and/or are in the first transition across the instability strip after leaving the main sequence (SU Cas). |