S Hya
| catalogues and names | S Hya, HD 76011, SAO 117236 |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 8h 53min 33,921sec | DEC: +3° 4' 6,81'' | ±0,43 arcsec | source: 16 |
| proper motion (J2000) | RA: -0,0006 arcsec/a | DEC: 0,011 arcsec/a | source: 16 | |
| radial velocity | 74 km/s | source: 11 | ||
| galactic coord. (B1950) | longitude: 224,99° | latitude: 28,42° | ||
| GCI unit vector (J2000) | X: -0,685993 | Y: 0,725637 | Z: 0,053531 | |
magnitude:
| visual | 11,85 (observed) | source: 20 |
| photographic | 8,8 | source: 16 |
spectral information:
| spectral class | M0 | source: 96 | |
| Morgan-Keenan | M4e-M8.0e | source: 30 | |
| B-magnitude | 13,24 ±0,02 | B-V-magnitude | 1,39 |
| U-magnitude | 13,54 ±0,02 | U-B-magnitude | 0,3 |
variability information:
| variability type | 180 |
| var. amplitude | 6,1 |
| var. period | 256,63 |
| var. epoch | 2443509 31. December 1977, 12:00:00 UT |
| next max light | 2451721,16 25. June 2000, 15:50:24 UT |
sources:
| 11 | General Catalogue of Stellar Radial Velocities |
| Wilson, R.E., General Catalogue of Stellar of Stellar Radial Radial Velocities, Washington, DC: Carnegie Institute of Washington, 1953 | |
| 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 | |
| 20 | Catalogue of Homogeneous Means in the UBV System |
| Mermilliod, J.C., Catalogue of Homogeneous Means in the UBV System, Institut d'Astronomie, Universite de Lausanne, 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 (J1950) | RA: 8h 50min 57,491sec | DEC: +3° 15' 30,38'' | ±0,041 arcsec |
| position (J2000) | RA: 8h 53min 33,907sec | DEC: +3° 4' 6,68'' | |
| proper motion J1950 (FK4) | RA: -0,0007 arcsec/a | DEC: 0,01 arcsec/a | ±0,007 arcsec/a in RA ±0,006 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0005 arcsec/a | DEC: 0,013 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 7,3 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | M3e |
| 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: 12278 |
| Durchmusterung | BD+03 2085 |
| Boss General Catalogue | 12278 |
| Henry Draper Catalogue | 76011 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 8h 50min 57,5sec | DEC: +3° 15' 30'' |
variability informations:
| variability type | M | pulsating variable star |
| magnitute at max. brightness | 7,2 | |
| magnitute at min. brightness | 13,3 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2443509 31. December 1977, 12:00:00 UT |
|
| period [d] | 256,63 | |
| next maximum light [JD] | 2451721,16 25. June 2000, 15:50:24 UT |
|
| rising time | 49 % of period |
spectral information
| spectral class | M4e-M8.0e |
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 | 42/2 |
| constellation | Hydra |
| notes on existence | The star is equivalent to '0420003 T'. |
variability type description
| variability type | description |
| M | Mira (Omicron) Ceti-type variables. These are long-period variable giants with characteristic late-type emission spectra (Me, Ce, Se) and light amplitudes from 2.5 to 11 mag in V. Their periodicity is well pronounced, and the periods lie in the range between 80 and 1000 days. Infrared amplitudes are usually less than in the visible and may be <2.5 mag. For example, in the K band they usually do not exceed 0.9 mag. If the amplitudes exceed 1 - 1.5 mag , but it is not certain that the true light amplitude exceeds 2.5 mag, the symbol "M" is followed by a colon, or the star is attributed to the semiregular class with a colon following the symbol for that type (SR). |