R CrB


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


catalogues and names R CrB, HR 5880, HD 141527, SAO 84015

data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)


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

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:

source of data: 30
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.