zeta 1 Aquarii

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

position, motion, parallax:

position (J2000)	RA: 22h 28min 49.7sec	DEC: -0° 1' 13''
position (B1900)	RA: 22h 23min 40.8sec	DEC: -0° 31' 53''
proper motion (J2000)	RA: 0.181 arcsec/a	DEC: 0.009 arcsec/a
radial velocity	29 km/s note: suspected variable radial velocity
rotational velocity	58 km/s (uncertain) (variable)
trigonometric parallax	0.022 arcsec
galactic coordinates	longitude: 65.35°	latitude: -46.33°

note (category: dynamical parallaxes):

0.040".

magnitude

visual magnitude

4.59
(original HR magnitude)

spectral / color information

spectral class	F6IV
IR-note	object is infrared source (uncertain identification)

note (category: spectra):

Combined spectrum with HR 8559, F3IV-V.

double/multiple star system information

number of components of multiple star system	3
separation	1.8 arcsec
mag difference (of double or brightest multiple)	0.2

note (category: double and multiple data):

Binary with HR 8559, speckle interferometric sep. 1.672" (1982.38). B* 4.51, 12v, 25.5y, a = 0.072".

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

position, motion, parallax:

position (J2000)	RA: 22h 28min 49.89sec	DEC: -0° 1' 12.72''	ą0.2 arcsec	source: 52
proper motion (J2000)	RA: 0.0131 arcsec/a	DEC: 0.031 arcsec/a		source: 25
radial velocity	29 km/s			source: 25
trigonometric parallax	0.022 arcsec		ą0.002 arcsec	source: 25
galactic coord. (B1950)	longitude: 65.36°	latitude: -46.33°

magnitude:

visual	4.52 (observed)	source: 25
photovisual	4.6	source: 2
photographic	4	source: 16

spectral information:

spectral class	F2		source: 96
Morgan-Keenan	F6IV		source: 25
B-magnitude	4.94 ą0.05	B-V-magnitude	0.42
U-magnitude	4.95 ą0.05	U-B-magnitude	0.01

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	2 arcsec
magnitude difference between brightest and second brightest component	0.2
position angle	198 °

component	magnitude	spectral class	catalogue(s)/name(s)
A	4.29	F2	z²Aquarii, 55 Aqr, HR 8559, HD 213052, SAO 146108
B	4.52	F2	z¹Aquarii, 55 Aqr, HR 8558, HD 213051, SAO 146107

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
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: 22h 26min 15.261sec	DEC: -0° 16' 35.27''	ą0.016 arcsec
position (J2000)	RA: 22h 28min 49.705sec	DEC: -0° 1' 13.03''
proper motion B1950 (FK4)	RA: 0.0119 arcsec/a	DEC: 0.014 arcsec/a	ą0.002 arcsec/a in RA ą0.002 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0121 arcsec/a	DEC: 0.009 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.6 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	F2
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: 31398
Durchmusterung	BD-00 4365B
Boss General Catalogue	31398
Henry Draper Catalogue	213051

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

position and proper motion:

position (J2000)	RA: 22h 28.8min	DEC: -0° 1'
proper motion (J2000)	RA: 0.18 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
-	1821	often	358°	3.8''	4.3	4.5	F3IV-V	STF2909
-	1994	often	198°	2''	4.3	4.5	F3IV-V	STF2909

discoverer information:

discoverer code	discoverer	reference
STF2909	Struve, F.G.W.	-

notes:

note	P = 760yr., a = 4.51", motion retrograde. A companion which may have been resolved accompanies one of the stars, P = 25.7yr. Proper motion of B +176 +013.

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

position:

position (B1900)

RA: 22h 23.7min

DEC: -0° 32'

magnitudes, spectral classes, orbital elements:

author:	R.S. Harrington	R.S. Harrington
date of observation:	1967	1967
magnitude of component A:	4.31	4.51
magnitude of component B:	4.31	4.51
spectral class component B:	F3V
spectral class component B:	F3V
period [y]:	856	25.5
semi-major axis [arcsec]:	5.055	0.072
inclination [deg]:	131.25	55.62
node [deg]:	310.22 (ascending)	19.61
equinox of node:	2000	2000
eccentricity:	0.495	0.26
time of periastron passage:	1957.6	1954.5
dates of ephemeris:	1968-1977
grade:	preliminary
reference:	Astron. J. 73, 508; 1968.	Ibid.

notes

The unseen star is associated with the visual secondary. Suspected variability of one of the components is unconfirmed.

other name(s)

STF 2909 Bb-P

catalogues and names	z¹Aqr, NSV 25909, 55 Aqr, HR 8558, HD 213051, SAO 146107, BD +0 4365 B, WDS 22288-0001B
constellation	Aquarius