X Sagittarii
catalogues and names
| catalogues and names | X Sgr, 3 Sgr, HR 6616, HD 161592, SAO 185755, CD -27 11930, FK5: 1464 |
| constellation | Sagittarius |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 17h 47min 33.6sec | DEC: -27° 49' 51'' | ||
| position (2000.72) | RA: 17h 47min 37sec | DEC: -27° 49' 52'' | ||
| position (B1900) | RA: 17h 41min 15.9sec | DEC: -27° 47' 34'' | ||
| proper motion (J2000) | RA: -0.001 arcsec/a | DEC: -0.009 arcsec/a | ||
| radial velocity | -13 km/s note: variable radial velocity |
|||
| rotational velocity | 24 km/s (uncertain) (variable) | |||
| trigonometric parallax | 0.035 arcsec | |||
| galactic coordinates | longitude: 1.17° | latitude: 0.21° | ||
magnitude
| visual magnitude | 4.54 (V on UBV Johnson system) |
spectral / color information
| spectral class | F7II |
| B-V-magnitude | 0.8 |
| U-B-magnitude | 0.5 |
| IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
variability information
| variable star identification | X Sgr |
| note (category: variability): | CDelta 4.24 - 4.84V, 7.01225d. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 17h 47min 33.638sec | DEC: -27° 49' 50.93'' | ±0.06 arcsec | source: 15 |
| position (2000.72) | RA: 17h 47min 37sec | DEC: -27° 49' 52'' | JD: 2451806.24 | |
| proper motion (J2000) | RA: -0.0001 arcsec/a | DEC: -0.009 arcsec/a | source: 25 | |
| radial velocity | -13 km/s | source: 25 | ||
| trigonometric parallax | 0.035 arcsec | ±0.003 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 1.17° | latitude: 0.21° | ||
magnitude:
| visual | 4.2 (observed) | source: 30 |
spectral information:
| spectral class | F8 | source: 96 | |
| Morgan-Keenan | F7II | source: 25 | |
| B-magnitude | 5.34 ±0.05 | B-V-magnitude | 0.8 |
| U-magnitude | 5.84 ±0.05 | U-B-magnitude | 0.5 |
variability information:
| variability type | 111 |
| var. amplitude | 0.7 |
| var. period | 7.01 |
| var. epoch | 2440742 4. June 1970, 12:00:00 UT |
| next max light | 2451810.79 23. September 2000, 06:57:36 UT |
sources:
| 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 | |
| 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: 17h 44min 24.664sec | DEC: -27° 48' 49.14'' | ±0.007 arcsec |
| position (2000.72) | RA: 17h 47min 37sec | DEC: -27° 49' 51'' | JD: 2451806.24 |
| position (J2000) | RA: 17h 47min 33.641sec | DEC: -27° 49' 50.8'' | |
| proper motion B1950 (FK4) | RA: 0.0001 arcsec/a | DEC: -0.009 arcsec/a | ±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0 arcsec/a | DEC: -0.008 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4.7 (accuracy: 2 decimals) |
| source of visual magnitude data | Arithmetic mean of maximum and minimum magnitudes of a variable star |
spectral information:
| spectral class | +++ |
| 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 | FK4, catalogue number: 1464 |
| Durchmusterung | CD-2711930 |
| Boss General Catalogue | 24135 |
| Henry Draper Catalogue | 161592 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (equinox 1950.0) | RA: 17h 44min 24.7sec | DEC: -27° 48' 49'' |
variability informations:
| variability type | DCEP | pulsating variable star |
| magnitute at max. brightness | 4.2 | |
| magnitute at min. brightness | 4.9 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2440741.7 4. June 1970, 04:48:00 UT |
|
| period [d] | 7.01283 | |
| next maximum light [JD] | 2451807.94574 20. September 2000, 10:41:52 UT |
|
| rising time | 36 % of period |
spectral information
| spectral class | F5-G2II |
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 | 72/7 |
| constellation | Sagittarius |
| notes on existence | The star is equivalent to '0720008 Y'. |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| DCEP | These are the classical cepheids, or Delta Cep-type variables. Comparatively young objects that have left the main sequence and evolved into the instability strip of the Hertzsprung-Russell (H-R) diagram, they obey the well-known Cepheid period-luminosity relation and belong to the young disk population. DCEP stars are present in open clusters. They display a certain relation between the shapes of their light curves and their periods. |