R Coronae Borealis
catalogues and names
catalogues and names | R CrB, HR 5880, HD 141527, SAO 84015, BD +28 2477 |
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 (2000.74) | RA: 15h 48min 36sec | DEC: +28° 9' 16'' | ||
position (B1900) | 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 |
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rotational velocity | 18 km/s (uncertain) (variable) | |||
trigonometric parallax | 0.01 arcsec | |||
galactic coordinates | longitude: 45.05° | latitude: 50.98° |
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 |
IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
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 |
position (2000.74) | RA: 15h 48min 36sec | DEC: +28° 9' 16'' | JD: 2451813.20 | |
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 arcsec | ±0.001 arcsec | source: 25 | |
galactic coord. (B1950) | longitude: 45.05° | latitude: 50.98° |
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 (B1950) | RA: 15h 46min 30.695sec | DEC: +28° 18' 32.24'' | ±0.017 arcsec |
position (2000.74) | RA: 15h 48min 37sec | DEC: +28° 9' 17'' | JD: 2451813.20 |
position (J2000) | RA: 15h 48min 34.418sec | DEC: +28° 9' 24.08'' | |
proper motion B1950 (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 (equinox 1950.0) | 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. |