catalogues and names

The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

SKY2000 - Master Star Catalog

Smithsonian Astrophysical Observatory Star Catalog

The Washington Visual Double Star Catalog, 1996.0

4th Catalog of Orbits of Visual Binaries

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

catalogues and names

catalogues and names	j Dra, phi Dra, 43 Dra, HR 6920, HD 170000, SAO 9084, BD +71 889, WDS 18208+7120A
constellation	Draco

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

position, motion, parallax:

position (J2000)	RA: 18h 20min 45.5sec	DEC: +71° 20' 16''
position (B1900)	RA: 18h 22min 11.4sec	DEC: +71° 17' 5''
proper motion (J2000)	RA: -0.004 arcsec/a	DEC: 0.04 arcsec/a
radial velocity	-16 km/s note: spectroscopic binaries, single lined spectra note: orbital data avaible
rotational velocity	88 km/s (uncertain) (variable)
trigonometric parallax	0.012 arcsec
galactic coordinates	longitude: 101.88°	latitude: 28.04°

note (category: dynamical parallaxes):

0.003".

magnitude

visual magnitude

4.22 (V on UBV Johnson system)

spectral / color information

spectral class	A0pSi:
B-V-magnitude	-0.1
U-B-magnitude	-0.33
R-I-magnitude

note (category: spectra):

Also classified B8Vp.

variability information

variable star identification

Phi Dra

note (category: variability):

Alpha CV, amp. 0.04V, 1.71646d. Same rotation period.

double/multiple star system information

number of components of multiple star system	3
separation	0.2 arcsec
mag difference (of double or brightest multiple)	1.7
component ID	AB

note (category: double and multiple data):

4.4, 6.1v, 271.7y, a = 0.392".

note (category: spectroscopic binaries):

26.768d, K 26.6k/s, V0 -20.8k/s, asini 9.02.

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

position, motion, parallax:

position (J2000)	RA: 18h 20min 45.43sec	DEC: +71° 20' 16.15''	±0.35 arcsec	source: 17
proper motion (J2000)	RA: -0.001 arcsec/a	DEC: 0.036 arcsec/a		source: 25
radial velocity	-16 km/s			source: 25
trigonometric parallax	0.012 arcsec		±0.001 arcsec	source: 25
galactic coord. (B1950)	longitude: 101.88°	latitude: 28.04°

magnitude:

visual	4.22 (observed)	source: 25
photovisual	4.2	source: 2
photographic	4.2	source: 16

spectral information:

spectral class	A0		source: 96
Morgan-Keenan	A0pSi:		source: 25
B-magnitude	4.12 ±0.05	B-V-magnitude	-0.1
U-magnitude	3.79 ±0.05	U-B-magnitude	-0.33

variability information:

source of data: 30

variability type	160
var. amplitude	0.04
var. period	1.72
var. epoch	2442229 30. June 1974, 12:00:00 UT
next max light	2452220.48 6. November 2001, 23:31:12 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	0.5 arcsec
magnitude difference between brightest and second brightest component	1.5
position angle	271 °

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
17	ACRS
Corbin, T.E., and S.E. Urban, Astrographic Catalog Reference Stars, United States Naval Observatory, 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
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 (B1950)	RA: 18h 21min 28.505sec	DEC: +71° 18' 42.23''	±0.009 arcsec
position (J2000)	RA: 18h 20min 45.453sec	DEC: +71° 20' 16.44''
proper motion B1950 (FK4)	RA: -0.002 arcsec/a	DEC: 0.041 arcsec/a	±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC
proper motion J2000 (FK5)	RA: -0.0009 arcsec/a	DEC: 0.04 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.2 (accuracy: 2 decimals)
source of visual magnitude data	Combined magnitude of component stars.

spectral information:

spectral class	A0p
source of spectral data	Taken from the HD with M stars reclassified by Miss Cannon.

remarks for duplicity and variability

Double star - see source catalog for source

catalogues

source catalogue	FK3, catalogue number: 693
Durchmusterung	BD+71 889
Boss General Catalogue	25114
Henry Draper Catalogue	170000

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

position and proper motion:

position (J2000)	RA: 18h 20.8min	DEC: +71° 20'
proper motion (J2000)	RA: -0.005 arcsec/a	DEC: 0.036 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
AB	1843	61	64°	0.6''	4.5	6	A0pSi:	STT 353
	1993		271°	0.5''
AB-C	1912	2	115°	70.8''	4.4	12.7	-	STT 353
	1962		116°	71.8''

discoverer information:

discoverer code	discoverer	reference
STT 353	Struve, O.	-

notes:

note	Phi Dra. A premature orbit has been computed. A is an Alpha CVn-type variable and spectroscopic binary.

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

position:

position (B1900)

RA: 18h 22.2min

DEC: +71° 17'

magnitudes, spectral classes, orbital elements:

author:	D. Olevic
date of observation:	1968
magnitude of component A:	4.4
magnitude of component B:	4.4
spectral class component B:	A0p
spectral class component B:	A0p
period [y]:	271.7
semi-major axis [arcsec]:	0.392
inclination [deg]:	118.96
node [deg]:	72.25
eccentricity:	0.44
time of periastron passage:	1720.75
dates of ephemeris:	1974-1980
grade:	indeterminate
reference:	Bull. Obs. Beograd No. 126, 49; 1975.

notes

Star A is a single-lined spectroscopic binary, probable P = 27 d,and also an Alpha CVn type variable.

other name(s)

STT 353, Phi Dra

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

position:

position (equinox 1950.0)

RA: 18h 21min 28.5sec

DEC: +71° 18' 42''

variability informations:

variability type	ACV	rotating variable star
magnitute at max. brightness	4.22
magnitute amplitude	0.04
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2442229.4 30. June 1974, 21:36:00 UT
period [d]	1.71646
next maximum light [JD]	2452219.1972 5. November 2001, 16:43:58 UT
rising time	60 % of period

spectral information

spectral class

A0p(Si)

references

to a study	Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph	no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'

miscanellous

ID in the GCVS catalogue	34/9021
constellation	Draco
notes on existence	The star is equivalent to '0350001 R'.
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.