The object was found in the following catalogues:
  1. The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

  2. SKY2000 - Master Star Catalog

  3. Smithsonian Astrophysical Observatory Star Catalog

  4. The Washington Visual Double Star Catalog, 1996.0

  5. Combined General Catalogue of Variable Stars (Vol. I-III)

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."

object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

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


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


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:

source of data: 30
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:

source of data: 19
separation between brightest and second brightest component 0,2 arcsec
position angle 110


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


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


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. -


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 (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)


to a chart/photograph Vol. I GCVS (see Kholopov et al. 1985-1988)


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.

Fast novae displaying rapid light increases and then, having achieved maximum light, fading by 3 mag in 100 or fewer days (GK Per);

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;

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;

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;

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).