b Hydrae


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 b Hya, bet Hya, HR 4552, HD 103192, SAO 202901, WDS 11529-3354
constellation Hydra

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


position, motion, parallax:

position (J2000) RA: 11h 52min 54,6sec DEC: -33 54' 29''
position (J1900) RA: 11h 47min 51,3sec DEC: -33 21' 6''
proper motion (J2000) RA: -0,05 arcsec/a DEC: 0,005 arcsec/a
radial velocity -1 km/s
rotational velocity 72 km/s (uncertain) (variable)
dynamical parallax 0,01 arcsec

magnitude

visual magnitude 4,28
(V on UBV Johnson system)

spectral / color information

spectral class B9IIIpSi
B-V-magnitude -0,1
U-B-magnitude -0,33
R-I-magnitude -0,08

variability information

variable star identification Bet Hya
note (category: variability): Alpha CV, amp. 0.04V, 0.04B, 2.344d.

double/multiple star system information

separation 0,8 arcsec
mag difference (of double or brightest multiple) 0,9
note Worley (1978) update of the IDS

data from SKY2000 - Master Star Catalog (Myers+ 1997)

position, motion, parallax:

position (J2000) RA: 11h 52min 54,532sec DEC: -33 54' 29,38'' 0,19 arcsec source: 16
proper motion (J2000) RA: -0,0046 arcsec/a DEC: -0,011 arcsec/a source: 25
radial velocity -1 km/s source: 25
galactic coord. (B1950) longitude: 289,28 latitude: 27,41
GCI unit vector (J2000) X: -0,829536 Y: 0,025675 Z: -0,557863

magnitude:

visual 4,28 (observed) source: 25
photovisual 3,5 source: 16
photographic 4,4 source: 2

spectral information:

spectral class B9 source: 96
Morgan-Keenan B9IIIpSi source: 25
B-magnitude 4,18 0,05 B-V-magnitude -0,1
U-magnitude 3,85 0,05 U-B-magnitude -0,33

variability information:

source of data: 30
variability type 160
var. amplitude 0,04
var. period 2,34
var. epoch 2442452
8. February 1975, 12:00:00 UT
next max light 2451622,46
18. March 2000, 23:02:24 UT

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 0,7 arcsec
magnitude difference between brightest and second brightest component 0,8
position angle 28

sources:

2 HD and HDE Catalogs
Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University
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
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
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: 11h 50min 22,635sec DEC: -33 37' 47,13'' 0,015 arcsec
position (J2000) RA: 11h 52min 54,56sec DEC: -33 54' 28,59''
proper motion J1950 (FK4) RA: -0,0042 arcsec/a DEC: 0,001 arcsec/a 0,003 arcsec/a in RA
0,003 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,004 arcsec/a DEC: 0,005 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 4,4 (accuracy: 2 decimals)
source of visual magnitude data Taken from Harvard or San Luis photometry.

spectral information:

spectral class B9
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Double star in Aitken's Double Star Catalogue (Aitken 1932)

catalogues

source catalogue GC, catalogue number: 16258
Durchmusterung CD-33 8018
Boss General Catalogue 16258
Henry Draper Catalogue 103192

data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

position and proper motion:

position (J2000) RA: 11h 52,9min DEC: -33 54'
proper motion (J2000) RA: -0,051 arcsec/a DEC: 0 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
- 1834 65 340 2,2'' 4,8 5,6 B9IIIpSi HJ 4478
1991 28 0,7''

discoverer information:

discoverer code discoverer reference
HJ 4478 Herschel, J. -

notes:

note Beta Hya. A is an Alpha CVn-type variable.

data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)

position:

position (J1950) RA: 11h 50min 22,6sec DEC: -33 37' 47''

variability informations:

variability type ACV rotating variable star
magnitute at max. brightness 4,27
magnitute amplitude 0,04
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2442451,78
8. February 1975, 06:43:12 UT
period [d] 2,344
next maximum light [JD] 2451621,508
18. March 2000, 00:11:31 UT

spectral information

spectral class B9IIIp(Si)

references

to a study Vol. II GCVS
to a chart/photograph no chart is avaible, but the star is contained in the 'Cordoba Durchmusterung'

miscanellous

ID in the GCVS catalogue 42/9002
constellation Hydra
notes on existence The star is equivalent to '0429005 eps'.
There are notes in published catalog.

variability type description

variability type description
ACV Alpha2 Canum Venaticorum variables. These are main-sequence stars with spectral types B8p-A7p and displaying strong magnetic fields.
Spectra show abnormally strong lines of Si, Sr, Cr, and rare earths whose intensities vary with rotation. They exhibit magnetic field and brightness changes (periods of 0.5-160 days or more). The amplitudes of the brightness changes are usually withine 0.01-0.1 mag in V.

ACVO
Rapidly oscillating Alpha2 CVn variables. These are nonradially pulsating, rotating magnetic variables of Ap spectral type (DO Eri). Pulsation periods are in the range of 6-12 mmag (0.004-0.01 days), while amplitudes of light variation caused by the pulsation are about 0.01 mag in V. The pulsational variations are superposed on those caused by rotation.