R CrB
| catalogues and names | R CrB, HR 5880, HD 141527, SAO 84015 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 15h 48min 34,4sec | DEC: +28° 9' 24'' |
| position (J1900) | RA: 15h 44min 27,1sec | DEC: +28° 27' 48'' |
| proper motion (J2000) | RA: -0,002 arcsec/a | DEC: -0,015 arcsec/a |
| radial velocity | 25 km/s note: variable radial velocity |
|
| rotational velocity | 18 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,01 arcsec | |
magnitude
| visual magnitude | 5,85 (V on UBV Johnson system) |
spectral / color information
| spectral class | G0Iep |
| B-V-magnitude | 0,77 |
| U-B-magnitude | 0,29 |
| note (category: spectra): | Hydrogen deficient carbon star. At minimum, emission of CaII, NaI, ScII, TiII, SrII, and FeII. Spectra at 2 and 10 micrometers indicate a thick dust shell either around R CrB or a companion. |
| note (category: colors): | IR excess. |
variability information
| variable star identification | R CrB |
| note (category: variability): | R CB 5.8 - 14.8v. The prototype star, discovered by Pigott in 1795. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 15h 48min 34,427sec | DEC: +28° 9' 24,14'' | ±0,2 arcsec | source: 52 |
| proper motion (J2000) | RA: -0,0001 arcsec/a | DEC: -0,012 arcsec/a | source: 25 | |
| radial velocity | 25 km/s | source: 25 | ||
| trigonometric parallax | 0,01 | ±0,001 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 45,05° | latitude: 50,98° | ||
| GCI unit vector (J2000) | X: -0,478334 | Y: -0,740622 | Z: 0,471885 | |
magnitude:
| visual | 5,7 (observed) | source: 31 |
| photographic | 6,4 | source: 16 |
spectral information:
| spectral class | G0 | source: 96 | |
| Morgan-Keenan | G0Iep | source: 25 | |
| B-magnitude | 6,62 ±0,05 | B-V-magnitude | 0,77 |
| U-magnitude | 6,91 ±0,05 | U-B-magnitude | 0,29 |
variability information:
| variability type | 230 |
| var. amplitude | 9,1 |
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 | |
| 31 | CRM' (non-GCVS variable data) |
| Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 1994 | |
| 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 (J1950) | RA: 15h 46min 30,695sec | DEC: +28° 18' 32,24'' | ±0,017 arcsec |
| position (J2000) | RA: 15h 48min 34,418sec | DEC: +28° 9' 24,08'' | |
| proper motion J1950 (FK4) | RA: -0,0003 arcsec/a | DEC: -0,017 arcsec/a | ±0,004 arcsec/a in RA ±0,003 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0002 arcsec/a | DEC: -0,015 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5,8 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | G0p |
| 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: 21257 |
| Durchmusterung | BD+28 2477 |
| Boss General Catalogue | 21257 |
| Henry Draper Catalogue | 141527 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 15h 46min 30,7sec | DEC: +28° 18' 32'' |
variability informations:
| variability type | RCB | eruptive variable star |
| magnitute at max. brightness | 5,71 | |
| magnitute at min. brightness | 14,8 | |
| photometric system | visual, photovisual or Johnson's V |
spectral information
| spectral class | C0,0(F8pep) |
references
| to a chart/photograph | Vol. I GCVS (see Kholopov et al. 1985-1988) |
miscanellous
| ID in the GCVS catalogue | 27/1 |
| constellation | Corona Borealis |
| notes on existence | The star is equivalent to '0270002 S'. |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| RCB | Variables of the R Coronae Borealis type. These are hydrogen-poor,carbon- and helium-rich, high-luminosity stars belonging to the spectral types Bpe-R, which are simultaneously eruptive and pulsating variables. They show slow nonperiodic fadings by 1-9 mag in V lasting from a month or more to several hundred days. These changes are superposed on cyclic pulsations with amplitudes up to several tenths of a magnitude and periods in the range 30-100 days. |