TW Piscis Austrini
catalogues and names
catalogues and names | TW PsA, HR 8721, HD 216803, SAO 214197, CD -32 17321 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
position (J2000) | RA: 22h 56min 24sec | DEC: -31° 33' 56'' | ||
position (2000.72) | RA: 22h 56min 26sec | DEC: -31° 33' 42'' | ||
position (B1900) | RA: 22h 50min 50.3sec | DEC: -32° 5' 41'' | ||
proper motion (J2000) | RA: 0.327 arcsec/a | DEC: -0.162 arcsec/a | ||
radial velocity | 6 km/s note: variable radial velocity |
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trigonometric parallax | 0.13 arcsec | |||
galactic coordinates | longitude: 15.94° | latitude: -64.61° |
magnitude
visual magnitude | 6.48 (V on UBV Johnson system) |
spectral / color information
spectral class | K4V |
B-V-magnitude | 1.1 |
U-B-magnitude | 1.02 |
R-I-magnitude |
variability information
variable star identification | TW PsA |
note (category: variability): | BY 6.44 - 6.49V, 10d. |
double/multiple star system information
note (category: double and multiple data): | CPM with HR 8728. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
position (J2000) | RA: 22h 56min 24.082sec | DEC: -31° 33' 56.1'' | ±0.19 arcsec | source: 16 |
position (2000.72) | RA: 22h 56min 26sec | DEC: -31° 33' 42'' | JD: 2451809.16 | |
proper motion (J2000) | RA: 0.0264 arcsec/a | DEC: -0.158 arcsec/a | source: 25 | |
radial velocity | 6 km/s | source: 25 | ||
trigonometric parallax | 0.13 arcsec | ±0.013 arcsec | source: 25 | |
galactic coord. (B1950) | longitude: 15.95° | latitude: -64.61° |
magnitude:
visual | 6.44 (observed) | source: 30 |
photovisual | 6.4 | source: 16 |
spectral information:
spectral class | K5 | source: 96 | |
Morgan-Keenan | K4Ve | source: 25 | |
B-magnitude | 7.58 ±0.05 | B-V-magnitude | 1.1 |
U-magnitude | 8.6 ±0.05 | U-B-magnitude | 1.02 |
variability information:
variability type | 440 |
var. amplitude | 0.07 |
var. period | 10.3 |
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: 22h 53min 37.402sec | DEC: -31° 49' 50.61'' | ±0.055 arcsec |
position (2000.72) | RA: 22h 56min 25sec | DEC: -31° 33' 35'' | JD: 2451809.16 |
position (J2000) | RA: 22h 56min 23.996sec | DEC: -31° 33' 56.28'' | |
proper motion B1950 (FK4) | RA: 0.0256 arcsec/a | DEC: -0.158 arcsec/a | ±0.011 arcsec/a in RA ±0.01 arcsec/a in DEC |
proper motion J2000 (FK5) | RA: 0.0256 arcsec/a | DEC: -0.162 arcsec/a | |
source of proper motion data | Determined by source catalog |
magnitude:
visual | 6.5 (accuracy: 2 decimals) |
source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
spectral class | K5 |
source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
source catalogue | GC, catalogue number: 31978 |
Durchmusterung | CD-3217321 |
Boss General Catalogue | 31978 |
Henry Draper Catalogue | 216803 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
position (equinox 1950.0) | RA: 22h 53min 37.4sec | DEC: -31° 49' 51'' |
variability informations:
variability type | BY | rotating variable star |
magnitute at max. brightness | 6.44 | |
magnitute at min. brightness | 6.51 | |
photometric system | visual, photovisual or Johnson's V | |
period [d] | 10.3 |
spectral information
spectral class | K5Ve |
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 'Cordoba Durchmusterung' |
miscanellous
ID in the GCVS catalogue | 67/30 |
constellation | Piscis Austrinus |
notes on existence | The star is equivalent to '0670031 TX'. |
variability type description
variability type | description |
BY | BY Draconis-type variables, which are emission-line dwarfs of dKe-dMe spectral type showing quasiperiodic light changes with periods from a fraction of a day to 120 days and amplitudes from several hundredths to 0.5 mag in V. The light variability is caused by axial rotation of a star with a variable degree of nonuniformity of the surface brightness (spots) and chromospheric activity. Some of these stars also show flares similar to those of UV Cet stars, and in those cases they also belong to the latter type and are simultaneously considered eruptive variables. |