Y Sagittarii
catalogues and names
| catalogues and names | Y Sgr, HR 6863, HD 168608, SAO 161376, BD -18 4926 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 18h 21min 23.1sec | DEC: -18° 51' 36'' | ||
| position (2000.72) | RA: 18h 21min 26sec | DEC: -18° 51' 35'' | ||
| position (B1900) | RA: 18h 15min 30sec | DEC: -18° 54' 16'' | ||
| proper motion (J2000) | RA: 0.011 arcsec/a | DEC: -0.009 arcsec/a | ||
| radial velocity | -3 km/s note: variable radial velocity |
|||
| rotational velocity | 18 km/s (uncertain) (variable) | |||
| trigonometric parallax | -0.006 arcsec | |||
| galactic coordinates | longitude: 12.79° | latitude: -2.14° | ||
| note (category: radial and/or rotational velocities): | Possibly long period. |
magnitude
| visual magnitude | 5.75 (V on UBV Johnson system) |
spectral / color information
| spectral class | F8I |
| B-V-magnitude | 0.94 |
| U-B-magnitude | 0.62 |
variability information
| variable star identification | Y Sgr |
| note (category: variability): | CDelta 5.40 - 6.10V, 5.77335d. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 18h 21min 22.997sec | DEC: -18° 51' 36.1'' | ±0.19 arcsec | source: 16 |
| position (2000.72) | RA: 18h 21min 26sec | DEC: -18° 51' 35'' | JD: 2451806.24 | |
| proper motion (J2000) | RA: 0.0001 arcsec/a | DEC: -0.01 arcsec/a | source: 25 | |
| radial velocity | -3 km/s | source: 25 | ||
| galactic coord. (B1950) | longitude: 12.79° | latitude: -2.14° | ||
magnitude:
| visual | 5.25 (observed) | source: 30 |
| photovisual | 5.9 | source: 16 |
spectral information:
| spectral class | F5 | source: 96 | |
| Morgan-Keenan | F8I | source: 25 | |
| B-magnitude | 6.69 ±0.05 | B-V-magnitude | 0.94 |
| U-magnitude | 7.31 ±0.05 | U-B-magnitude | 0.62 |
variability information:
| variability type | 111 |
| var. amplitude | 0.99 |
| var. period | 5.77 |
| var. epoch | 2440762 24. June 1970, 12:00:00 UT |
| next max light | 2451811.55 24. September 2000, 01:12:00 UT |
sources:
| 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 | |
| 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: 18h 18min 26.491sec | DEC: -18° 53' 2.76'' | ±0.033 arcsec |
| position (2000.72) | RA: 18h 21min 25sec | DEC: -18° 51' 35'' | JD: 2451806.24 |
| position (J2000) | RA: 18h 21min 23.072sec | DEC: -18° 51' 36.22'' | |
| proper motion B1950 (FK4) | RA: 0.0007 arcsec/a | DEC: -0.01 arcsec/a | ±0.007 arcsec/a in RA ±0.007 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0.0008 arcsec/a | DEC: -0.009 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5.4 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | F5p |
| 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: 25038 |
| Durchmusterung | BD-18 4926 |
| Boss General Catalogue | 25038 |
| Henry Draper Catalogue | 168608 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (equinox 1950.0) | RA: 18h 18min 26.5sec | DEC: -18° 53' 3'' |
variability informations:
| variability type | DCEP | pulsating variable star |
| magnitute at max. brightness | 5.25 | |
| magnitute at min. brightness | 6.24 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2440762.38 24. June 1970, 21:07:12 UT |
|
| period [d] | 5.77335 | |
| next maximum light [JD] | 2451806.79855 19. September 2000, 07:09:55 UT |
|
| rising time | 34 % of period |
spectral information
| spectral class | F5-G0Ib-II |
references
| to a study | Vol. III GCVS |
| to a chart/photograph | Vol. I GCVS (see Kholopov et al. 1985-1988) |
miscanellous
| ID in the GCVS catalogue | 72/8 |
| constellation | Sagittarius |
| notes on existence | The star is equivalent to '0720009 Z'. |
| 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. |