iota 1 Librae

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

position, motion, parallax:

position (J2000)	RA: 15h 12min 13.3sec	DEC: -19° 47' 30''
position (B1900)	RA: 15h 6min 31.1sec	DEC: -19° 24' 48''
proper motion (J2000)	RA: -0.036 arcsec/a	DEC: -0.039 arcsec/a
radial velocity	-12 km/s note: spectroscopic binaries, double lined spectra note: orbital data avaible
rotational velocity	54 km/s (uncertain) (variable)
trigonometric parallax	0.03 arcsec
galactic coordinates	longitude: 342.69°	latitude: 32°

magnitude

visual magnitude

4.54
(V on UBV Johnson system)

spectral / color information

spectral class	A0pSi
B-V-magnitude	-0.08
U-B-magnitude	-0.35
R-I-magnitude

note (category: spectra):

Also classified B8VpSi, B9IV-V; component B G5IV.

variability information

variable star identification

6981

note (category: variability):

ADS 9532A, Alpha CV?, 4.53 - 4.56V. Spectrum variable.

double/multiple star system information

number of components of multiple star system	4
separation	0.1 arcsec
mag difference (of double or brightest multiple)	0.6
component ID	AP

note (category: double and multiple data):

AP 5.1 B9IV, 5.6 B9V, 23.42y, a = 0.116", combined light, colors. Mean mass 5 solar. BC, 10.5, 11.2v sep. 1.9". A physical pair in orbital motion about AP at 58"; possibly quintuple system.

note (category: spectroscopic binaries):

ADS 9532A, 22.35y D, K 3.4k/s, V0 -14.2k/s, asini 358.

miscellaneous information

note (category: group membership):

Member of Pleiades group.

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

position, motion, parallax:

position (J2000)	RA: 15h 12min 13.289sec	DEC: -19° 47' 30.26''	±0.06 arcsec	source: 15
proper motion (J2000)	RA: -0.0025 arcsec/a	DEC: -0.039 arcsec/a		source: 25
radial velocity	-12 km/s			source: 25
trigonometric parallax	0.03 arcsec		±0.003 arcsec	source: 25
galactic coord. (B1950)	longitude: 342.69°	latitude: 32°

magnitude:

visual	4.54 (observed)	source: 25
photovisual	4.7	source: 2
photographic	4.7	source: 2

spectral information:

spectral class	A0		source: 96
Morgan-Keenan	A0pSi		source: 25
B-magnitude	4.46 ±0.05	B-V-magnitude	-0.08
U-magnitude	4.11 ±0.05	U-B-magnitude	-0.35

variability information:

source of data: 28

variability type	160
var. amplitude	0.03

double/multiple star system information:

source of data: 19

magnitude difference between brightest and second brightest component

0.4

component	magnitude	spectral class	catalogue(s)/name(s)
A	4.54	A0	i¹Librae, 24 Lib, HR 5652, HD 134759, SAO 159090
B	9.68	G5

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
15	FK5, FK5 Extension and FK5 Supplement
Fricke, W., H. Schwan and T. Lederle, "Fifth Fundamental Catalogue (FK5), Part I. The Basic Fundamental Stars," Veroff. Astronomisches Recheninstitut, No. 32, Heidelberg, Germany, 1988, and Fricke, W., H. Schwan, and T.E. Corbin, "Fifth Fundamental Catalogue (FK5), Part II. The FK5 Extension," Veröff. Astronomisches Recheninstitut, No. 33, Heidelberg, Germany, 1991
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
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 9min 21.946sec	DEC: -19° 36' 13.7''	±0.004 arcsec
position (J2000)	RA: 15h 12min 13.284sec	DEC: -19° 47' 30.28''
proper motion B1950 (FK4)	RA: -0.0027 arcsec/a	DEC: -0.043 arcsec/a	±0.001 arcsec/a in RA ±0.001 arcsec/a in DEC
proper motion J2000 (FK5)	RA: -0.0026 arcsec/a	DEC: -0.039 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.7 (accuracy: 2 decimals)
source of visual magnitude data	Taken from the "Henry Draper Catalogue".

spectral information:

spectral class	A0p
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue	FK4, catalogue number: 559
Durchmusterung	BD-19 4047
Boss General Catalogue	20433
Henry Draper Catalogue	134759

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

position and proper motion:

position (J2000)	RA: 15h 12.2min	DEC: -19° 48'
proper motion (J2000)	RA: -0.036 arcsec/a	DEC: -0.039 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
Aa	1940	40	°	''	5.1	5.5	B9IV	B 2351
Aa-B	1782	15	111°	57.8''	4.53	9.82	-	H 44
BC	1878	16	20°	1.9''	10.4	10.9	G5IV	BU 618
BC	1966	16	15°	-	10.4	10.9	G5IV	BU 618

discoverer information:

discoverer code	discoverer	reference
B 2351	Bos, W.H. van den	-
H 44	Herschel, W.	-
BU 618	Burnham, S.W.	-

notes:

note	Iota (1) Lib. P = 23.4yr., a = 0.12", motion retro- grade. There is evidence for a spectroscopic subsystem, and BC is physical, so the system is probably quin- tuple. Alternate spectrum of Aa: ApSi. Aa-B: H VI 44.

data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)

position:

position (B1900)

RA: 15h 6.5min

DEC: -19° 25'

magnitudes, spectral classes, orbital elements:

author:	W.D. Heintz
date of observation:	1978
magnitude of component A:	5.1
magnitude of component B:	5.1
spectral class component B:	A0p
spectral class component B:	A0p
period [y]:	23.42
semi-major axis [arcsec]:	0.116
inclination [deg]:	162
node [deg]:	34.6 (ascending)
equinox of node:	2000
eccentricity:	0.3
time of periastron passage:	1972.93
dates of ephemeris:	1980-1998
grade:	reliable
reference:	Astron. Astrophys. Suppl. 47, 569; 1982.

notes

Double-lined spectrum, frequently blended. The second spectrum may belong, not to the visual companion, but to a third star, since the RV variation - if real - is faster and larger than the visual orbit with its low inclination could cause. The pair BC = BU 618 (mag. 9.82, 1.9") is 58" from the bright pair and physical, so that the system is probably quintuple. 15108-0432 One component is probably variable; position angles have been reversed repeatedly.

other name(s)

B 2351, Iota Lib

data from Combined General Catalogue of Variable Stars (suspected variables) (Kholopov+ 1998)

position:

position (equinox 1950.0)

RA: 15h 9min 22sec

DEC: -19° 36' 14''

variability informations:

variability type	ACV:	rotating variable star
magnitute at max. brightness	4.53
magnitute at min. brightness	4.56
photometric system	visual, photovisual or Johnson's V

spectral information

spectral class

references

to a study

2416D (designation: -19 4047)

miscanellous

There are notes in the published catalog (Kukarkin et al.(1982)).

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.

catalogues and names	i¹Lib, NSV 06981, 24 Lib, HR 5652, HD 134759, SAO 159090, BD -19 4047, FK5: 559, WDS 15122-1948A
constellation	Libra