T CrB
| catalogues and names | T CrB, HR 5958, HD 143454, SAO 84129, WDS 15595+2555 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | "Blaze Star." |
position, motion, parallax:
| position (J2000) | RA: 15h 59min 30,2sec | DEC: +25° 55' 13'' |
| position (J1900) | RA: 15h 55min 19sec | DEC: +26° 12' 13'' |
| proper motion (J2000) | RA: -0,005 arcsec/a | DEC: 0,013 arcsec/a |
| radial velocity | -29 km/s note: spectroscopic binaries note: orbital data avaible |
|
magnitude
| visual magnitude | 2 (original HR magnitude) |
spectral / color information
| spectral class | sdBe+gM3+Q |
| B-V-magnitude | 0,1 |
| R-I-magnitude | 1,56 |
variability information
| variable star identification | T CrB |
| note (category: variability): | Nr 2.0 - 10.8v, 29000d? Outbursts 1866 and 1946. V and B-V for 1946 maximum. Near maximum 9.88V, +1.40(B-V), +0.59(U-B). |
double/multiple star system information
| separation | 0,2 arcsec |
| note | Worley (1978) update of the IDS |
| note (category: double and multiple data): | Visual companion doubtful. |
| note (category: spectroscopic binaries): | 227.6d, K 24.0k/s, V0 -27.0k/s, msin3i 2.60, asini 75.0. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 15h 59min 30,158sec | DEC: +25° 55' 12,7'' | ±0,2 arcsec | source: 52 |
| proper motion (J2000) | RA: -0,0008 arcsec/a | DEC: 0,018 arcsec/a | source: 25 | |
| radial velocity | -29 km/s | source: 25 | ||
| galactic coord. (B1950) | longitude: 42,37° | latitude: 48,16° | ||
| GCI unit vector (J2000) | X: -0,451391 | Y: -0,777929 | Z: 0,437119 | |
magnitude:
| visual | 9,9 (observed) | source: 20 |
| photographic | 11,4 | source: 16 |
spectral information:
| spectral class | PEC | source: 29 | |
| Morgan-Keenan | sdBe+gM3 | source: 25 | |
| B-magnitude | 11,3 ±0,024 | B-V-magnitude | 1,4 |
| U-magnitude | 11,89 ±0,059 | U-B-magnitude | 0,59 |
variability information:
| variability type | 263 |
| var. amplitude | 8,8 |
| var. period | 29000 |
| var. epoch | 2431860 8. February 1946, 12:00:00 UT |
| next max light | 2460860 3. July 2025, 12:00:00 UT |
double/multiple star system information:
| separation between brightest and second brightest component | 0,2 arcsec |
| position angle | 110 ° |
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 | |
| 19 | WDS Catalog |
| Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996 | |
| 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 | |
| 25 | Bright Star Catalogue, 5th edition |
| Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994 | |
| 29 | SAOJ2000 |
| SAO on FK5 at J2000, 1989 | |
| 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) | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (J1950) | RA: 15h 57min 24,505sec | DEC: +26° 3' 39,04'' | ±0,032 arcsec |
| position (J2000) | RA: 15h 59min 30,164sec | DEC: +25° 55' 12,82'' | |
| proper motion J1950 (FK4) | RA: -0,0005 arcsec/a | DEC: 0,011 arcsec/a | ±0,005 arcsec/a in RA ±0,005 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0004 arcsec/a | DEC: 0,013 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 9,9 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
| photographic | 11,3 (accuracy: 2 decimals) |
spectral information:
| spectral class | Pec |
| 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: 21491 |
| Durchmusterung | BD+26 2765 |
| Boss General Catalogue | 21491 |
| Henry Draper Catalogue | 143454 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 15h 59,5min | DEC: +25° 55' |
| proper motion (J2000) | RA: -0,009 arcsec/a | DEC: 0,009 arcsec/a |
double/multiple star system information:
| component | year | number of measures | position angle | angular separation | magnitude of 1st component | magnitude of 2nd component | spectral class(es) | discoverer code |
| - | 1946 | 1 | 110° | 0,2'' | 2 | - | - | JEF 2 |
discoverer information:
| discoverer code | discoverer | reference |
| JEF 2 | Jeffers, H.M. | - |
notes:
| note | The observation is doubtful. Others of same year do not suggest duplicity. This is the recurrent nova T CrB, with composite spectrum; sdBe+gM3+Q. |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 15h 57min 24,5sec | DEC: +26° 3' 39'' |
variability informations:
| variability type | NR | cataclysmic (explosive and novalike) variables |
| magnitute at max. brightness | 2 | |
| magnitute at min. brightness | 10,8 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2431860 8. February 1946, 12:00:00 UT |
|
| year of outburst for nova | 1946 | |
| mean cycle time [d] | 29000 |
spectral information
| spectral class | M3III+pec(NOVA) |
references
| to a chart/photograph | Vol. I GCVS (see Kholopov et al. 1985-1988) |
miscanellous
| ID in the GCVS catalogue | 27/3 |
| constellation | Corona Borealis |
| notes on existence | The star is equivalent to '0270004 U'. |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| NR | Novae. Close binary systems with orbital periods from 0.05 to 230 days. One of the components of these systems is a hot dwarf star that suddenly, during a time interval from one to several dozen or several hundred days, increases its brightness by 7-19 mag in V, then returns gradually to its former brightness over several months, years, or decades. Small changes at minimum light may be present. Cool components may be giants, subgiants, or dwarfs of K-M type. The spectra of novae near maximum light resemble A-F absorption spectra of luminous stars at first. Then broad emission lines (bands) of hydrogen, helium, and other elements with absorption components indicating the presence of a rapidly expanding envelope appear in the spectrum. As the light decreases, the composite spectrum begins to show forbidden lines characteristic of the spectra of gas nebulae excited by hot stars. At minimum light, the spectra of novae are generally continuous or resemble the spectra of Wolf-Rayet stars. Only spectra of the most massive systems show traces of cool components. Some novae reveal pulsations of hot components with periods of approximately 100 s and amplitudes of about 0.05 mag in V after an outburst. Some novae eventually turn out to be eclipsing systems. According to the features of their light variations,novae are subdivided into fast (NA), slow (NB), very slow (NC),and recurrent (NR) categories. NA Fast novae displaying rapid light increases and then, having achieved maximum light, fading by 3 mag in 100 or fewer days (GK Per); NB Slow novae that fade after maximum light by 3 mag in >= 150 days (RR Pic). Here the presence of the well-known "dip" in the light curves of novae similar to T Aur and DQ Her is not taken into account: The rate of fading is estimated on the basis of a smooth curve, its parts before and after the "dip" being a direct continuation of one another; NC Novae with a very slow development and remaining at maximum light for more than a decade, then fading very slowly. Before an outburst these objects may show long-period light changes with amplitudes of 1-2 mag in V (RR Tel); cool components of these systems are probably giants or supergiants, sometimes semiregular variables, and even Mira variables. Outburst amplitudes may reach 10 mag. High excitation emission spectra resemble those of planetary nebulae, Wolf-Rayet stars, and symbiotic variables. The possibility that these objects are planetary nebulae in the process of formation is not excluded; NL Novalike variables, which are insufficiently studied objects resembling novae by the characteristics of their light changes or by spectral features. This type includes, in addition to variables showing novalike outbursts, objects with no bursts ever observed; the spectra of novalike variables resemble those of old novae, and small light changes resemble those typical for old novae at minimum light. However, quite often a detailed investigation makes it possible to reclassify some representatives of this highly inhomogeneous group of objects into other types; NR Recurrent novae, which differ from typical novae by the fact that two or more outbursts (instead of a single one) separated by 10-80 years have been observed (T CrB). |