T Cephei
catalogues and names
| catalogues and names | T Cep, HR 8113, HD 202012, SAO 19229, BD +67 1291 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 21h 9min 32sec | DEC: +68° 29' 25'' | ||
| position (2000.72) | RA: 21h 9min 33sec | DEC: +68° 29' 36'' | ||
| position (B1900) | RA: 21h 8min 13.1sec | DEC: +68° 5' 0'' | ||
| proper motion (J2000) | RA: -0.032 arcsec/a | DEC: -0.067 arcsec/a | ||
| radial velocity | -12 km/s note: variable radial velocity |
|||
| trigonometric parallax | 0.002 arcsec | |||
| galactic coordinates | longitude: 104.81° | latitude: 13.84° | ||
magnitude
| visual magnitude | 7.33 (V on UBV Johnson system) |
spectral / color information
| spectral class | M7IIIe |
| B-V-magnitude | 1.49 |
| U-B-magnitude | 0.33 |
| IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
| note (category: spectra): | Weak-lined technetium star. SiO source. Also classified M5.5e-M8.8e. |
variability information
| variable star identification | T Cep |
| note (category: variability): | M 5.2 - 11.3v. Period varies; mean period 388.14d, range 379 - 392.7d. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 21h 9min 31.757sec | DEC: +68° 29' 27.48'' | ±0.2 arcsec | source: 52 |
| position (2000.72) | RA: 21h 9min 33sec | DEC: +68° 29' 38'' | JD: 2451806.35 | |
| proper motion (J2000) | RA: -0.0087 arcsec/a | DEC: -0.041 arcsec/a | source: 25 | |
| radial velocity | -12 km/s | source: 25 | ||
| trigonometric parallax | 0.002 arcsec | - | source: 25 | |
| galactic coord. (B1950) | longitude: 104.81° | latitude: 13.84° | ||
magnitude:
| visual | 7.33 (observed) | source: 25 |
| photographic | 8 | source: 16 |
spectral information:
| spectral class | M0 | source: 96 | |
| Morgan-Keenan | M7IIIe | source: 25 | |
| B-magnitude | 8.82 ±0.05 | B-V-magnitude | 1.49 |
| U-magnitude | 9.15 ±0.05 | U-B-magnitude | 0.33 |
variability information:
| variability type | 180 |
| var. amplitude | 6.1 |
| var. period | 388.14 |
| var. epoch | 2444177 30. October 1979, 12:00:00 UT |
| next max light | 2451939.8 30. January 2001, 07:12:00 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 | |
| 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 8min 52.87sec | DEC: +68° 17' 11.85'' | ±0.086 arcsec |
| position (2000.72) | RA: 21h 9min 33sec | DEC: +68° 29' 39'' | JD: 2451806.35 |
| position (J2000) | RA: 21h 9min 32.013sec | DEC: +68° 29' 24.89'' | |
| proper motion B1950 (FK4) | RA: -0.0063 arcsec/a | DEC: -0.062 arcsec/a | ±0.012 arcsec/a in RA ±0.022 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.0058 arcsec/a | DEC: -0.067 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5.2 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | M6e |
| 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: 29611 |
| Durchmusterung | BD+67 1291 |
| Boss General Catalogue | 29611 |
| Henry Draper Catalogue | 202012 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (equinox 1950.0) | RA: 21h 8min 52.9sec | DEC: +68° 17' 12'' |
variability informations:
| variability type | M | pulsating variable star |
| magnitute at max. brightness | 5.2 | |
| magnitute at min. brightness | 11.3 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2444177 30. October 1979, 12:00:00 UT |
|
| period [d] | 388.14 | |
| next maximum light [JD] | 2451939.8 30. January 2001, 07:12:00 UT |
|
| rising time | 54 % of period |
spectral information
| spectral class | M5.5e-M8.8e |
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 | 20/3 |
| constellation | Cepheus |
| notes on existence | The star is equivalent to '0200004 U'. |
| There are notes in published catalog. | |
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). |