h Aquilae

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 h Aql, eta Aql, 55 Aql, HR 7570, HD 187929, SAO 125159, FK5: 746
constellation Aquila

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: 19h 52min 28,4sec DEC: +1 0' 20''
position (J1900) RA: 19h 47min 22,7sec DEC: +0 44' 56''
proper motion (J2000) RA: 0,011 arcsec/a DEC: -0,007 arcsec/a
radial velocity -15 km/s
note: spectroscopic binaries
rotational velocity 0 km/s (uncertain) (variable)
trigonometric parallax 0,01 arcsec


visual magnitude 3,9
(V on UBV Johnson system)

spectral / color information

spectral class F6Ib
B-V-magnitude 0,89
U-B-magnitude 0,51
R-I-magnitude 0,47
note (category: spectra): Also classified F6Ib-G4Ib. UV suggests A0V companion.

variability information

variable star identification Eta Aql
note (category: variability): Discovered by Pigott in 1784. CDelta 3.50 - 4.30V, 7.176641d. Period changes. Variable He 10830 in emission and absorption.

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

position, motion, parallax:

position (J2000) RA: 19h 52min 28,374sec DEC: +1 0' 20,37'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,0007 arcsec/a DEC: -0,007 arcsec/a source: 25
radial velocity -15 km/s source: 25
trigonometric parallax 0,01 0,001 arcsec source: 25
galactic coord. (B1950) longitude: 40,94 latitude: -13,07
GCI unit vector (J2000) X: 0,47122 Y: -0,881841 Z: 0,017551


visual 3,5 (observed) source: 31

spectral information:

spectral class G0 source: 96
Morgan-Keenan F6Ib source: 25
B-magnitude 4,79 0,05 B-V-magnitude 0,89
U-magnitude 5,3 0,05 U-B-magnitude 0,51

variability information:

source of data: 30
variability type 111
var. amplitude 0,91
var. period 7,18
var. epoch 2436085
3. September 1957, 12:00:00 UT
next max light 2451622,52
19. March 2000, 00:28:48 UT


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
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
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: 19h 49min 55,525sec DEC: +0 52' 33,23'' 0,005 arcsec
position (J2000) RA: 19h 52min 28,373sec DEC: +1 0' 20,25''
proper motion J1950 (FK4) RA: 0,0005 arcsec/a DEC: -0,006 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0007 arcsec/a DEC: -0,008 arcsec/a
source of proper motion data Determined by source catalog


visual 4 (accuracy: 2 decimals)
source of visual magnitude data Arithmetic mean of maximum and minimum magnitudes of a variable star

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


source catalogue FK4, catalogue number: 746
Durchmusterung BD+00 4337
Boss General Catalogue 27517
Henry Draper Catalogue 187929

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


position (J1950) RA: 19h 49min 55,5sec DEC: +0 52' 33''

variability informations:

variability type DCEP pulsating variable star
magnitute at max. brightness 3,48
magnitute at min. brightness 4,39
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2436084,656
3. September 1957, 03:44:38 UT
period [d] 7,176641
next maximum light [JD] 2451622,083765
18. March 2000, 14:00:37 UT
rising time 32 % of period

spectral information

spectral class F6Ib-G4Ib


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'


ID in the GCVS catalogue 5/9007
constellation Aquarius
notes on existence The star is equivalent to '0059018 sig'.
There are notes in published catalog.

variability type description

variability type description
DCEP These are the classical cepheids, or Delta Cep-type variables. Comparatively young objects that have left the main sequence and evolved into the instability strip of the Hertzsprung-Russell (H-R) diagram, they obey the well-known Cepheid period-luminosity relation and belong to the young disk population. DCEP stars are present in open clusters. They display a certain relation between the shapes of their light curves and their periods.