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	h Ori, eta Ori, 28 Ori, HR 1788, HD 35411, SAO 132071, BD -2 1235, WDS 05245-0224A
constellation	Orion

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

position, motion, parallax:

position (J2000)	RA: 5h 24min 28.6sec	DEC: -2° 23' 49''
position (B1900)	RA: 5h 19min 26.9sec	DEC: -2° 29' 21''
proper motion (J2000)	RA: 0.002 arcsec/a	DEC: 0 arcsec/a
radial velocity	20 km/s note: spectroscopic binaries, double lined spectra note: orbital data avaible
rotational velocity	46 km/s (uncertain) (variable)
trigonometric parallax	0.007 arcsec
galactic coordinates	longitude: 204.87°	latitude: -20.39°

note (category: radial and/or rotational velocities):

Expanding circumstellar shell.

note (category: dynamical parallaxes):

0.005".

magnitude

visual magnitude

3.36 (V on UBV Johnson system)

spectral / color information

spectral class	B1V+B2e
B-V-magnitude	-0.17
U-B-magnitude	-0.92
R-I-magnitude

variability information

variable star identification

Eta Ori

note (category: variability):

EA + Beta C 3.31 - 3.60V, 3.14 - 3.35B, 7.989268d. Also sinusoidal pulsation period, amp. 0.05V, 0.30197 or 0.30145d.

double/multiple star system information

number of components of multiple star system	5
separation	1.5 arcsec
mag difference (of double or brightest multiple)	1.4
component ID	AB

note (category: double and multiple data):

ADS 4002A is SB triple system, abc with periods 9.2y and 7.989d. Speckle interferometry gives 9.219y, a = 0.036" for for ab x c. Visual components AB, binary, 3.8, 4.8v, sep. 1.650"; C, 9.4v at 115". The total mass of the quintuple system exceeds 50 solar masses, the most massive component being about 17 solar masses.

note (category: spectroscopic binaries):

ab, 7.9841d, K 145.2k/s, V0 +35.9k/s, asini 15.9. abc, 9.2y, K 17.5k/s, V0 +19.5k/s, asini 805. Resolved by speckle interferometry at 4-meter Mayall telescope, sep. 0.04"; vsini secondary 39k/s.

miscellaneous information

note (category: group membership):

Ori OB1a; Orion belt; cluster CR 70.

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

position, motion, parallax:

position (J2000)	RA: 5h 24min 28.633sec	DEC: -2° 23' 49.38''	±0.43 arcsec	source: 16
proper motion (J2000)	RA: 0.0001 arcsec/a	DEC: 0.001 arcsec/a		source: 25
radial velocity	20 km/s			source: 25
trigonometric parallax	0.007 arcsec		±0.001 arcsec	source: 25
galactic coord. (B1950)	longitude: 204.87°	latitude: -20.39°

magnitude:

visual	3.3 (observed)	source: 31
photovisual	3.4	source: 2
photographic	3.2	source: 2

spectral information:

spectral class	B1		source: 96
Morgan-Keenan	B1V+B2e		source: 25
B-magnitude	3.19 ±0.05	B-V-magnitude	-0.17
U-magnitude	2.27 ±0.05	U-B-magnitude	-0.92

variability information:

source of data: 30

variability type	10
var. amplitude	0.29
var. period	7.99
var. epoch	2415762 12. January 1902, 12:00:00 UT
next max light	2452220.37 6. November 2001, 20:52:48 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	1.7 arcsec
magnitude difference between brightest and second brightest component	1
position angle	78 °

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
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 (B1950)	RA: 5h 21min 57.676sec	DEC: -2° 26' 29.58''	±0.014 arcsec
position (J2000)	RA: 5h 24min 28.638sec	DEC: -2° 23' 49.38''
proper motion B1950 (FK4)	RA: -0.0002 arcsec/a	DEC: 0.001 arcsec/a	±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0001 arcsec/a	DEC: 0 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	3.4 (accuracy: 2 decimals)
source of visual magnitude data	Combined magnitude of component stars.

spectral information:

spectral class	B1
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: 200
Durchmusterung	BD-02 1235
Boss General Catalogue	6655
Henry Draper Catalogue	35411

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

position and proper motion:

position (J2000)	RA: 5h 24.5min	DEC: -2° 24'
proper motion (J2000)	RA: 0.003 arcsec/a	DEC: -0.001 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	1975	16	134°	0.1''	3.36	-	B1V+B2e	MCA 18
	1988		116°	-
Aa-B	1848	often	87°	1''	3.8	4.8	B1V+B2e	DA 5
	1989		78°	1.7''
Aa-C	1904	3	51°	115.1''	3.4	9.4	B1V+B2e	H 67
	1977		52°	116.1''

discoverer information:

discoverer code	discoverer	reference
MCA 18	McAlister, H.A.	(Astron. J. 106, 1639; 1993.)
DA 5	Dawes, W.R.	-
H 67	Herschel, W.	-

notes:

note	Eta Ori. A is a spectroscopic and eclipsing binary, P = 7.99d. A has been resolved into a third component by speckle interferometry. A spectroscopic period of 9.51y has been determined. H VI 67.

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

position:

position (B1900)

RA: 5h 19.4min

DEC: -2° 29'

magnitudes, spectral classes, orbital elements:

author:	H.A. McAlister
magnitude of component A:	3.8
magnitude of component B:	3.8
spectral class component B:	B1V
spectral class component B:	B1V
period [y]:	9.219
semi-major axis [arcsec]:	0.036
inclination [deg]:	90
node [deg]:	312.1 (ascending)
eccentricity:	0.43
time of periastron passage:	1906.687
grade:	indeterminate
reference:	Pub. Astron. Soc. Pacific 88, 957; 1976.

notes

Quintuple; the primary is a double-lined spectroscopic triple with periods 7.99 d (Aab) and 9.2 yr (Aab-c). The close pair eclipses, and shows an 8-hour pulsation in one of the components. Using the elements P, T, e, and the longitude of periastron for the 9-year orbit, from a spectroscopic orbit by E.R. Ziska and W.R. Beardsley (Astron. J. 86, 1944; 1981), and assuming the orbit edge-on, the semi-axis major and the node are based on a single speckle observation. The ascending node has been reversed. The visual companions are star B (mag. 4.8, 1.5") in slow retrograde motion, and C (mag. 9.4, 115").

other name(s)

Eta Ori

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

position:

position (equinox 1950.0)

RA: 5h 21min 57.7sec

DEC: -2° 26' 30''

variability informations:

variability type	EA+BCEP:	close binary eclipsing system pulsating variable star
magnitute at max. brightness	3.31
magnitute at min. brightness	3.6
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2415761.826 12. January 1902, 07:49:26 UT
period [d]	7.989268
next maximum light [JD]	2452224.845152 11. November 2001, 08:17:01 UT

spectral information

spectral class

B0.5Vea+B3V

references

to a study	Vol. II GCVS
to a chart/photograph	Vol. I GCVS (see Kholopov et al. 1985-1988)

miscanellous

ID in the GCVS catalogue	60/9007
constellation	Orion
notes on existence	The star is equivalent to '06090151omi 1'.
There are notes in published catalog.

variability type description

variability type	description
EA	Eclipsing binary systems. These are binary systems with orbital planes so close to the observer's line of sight (the inclination i of the orbital plane to the plane orthogonal to the line of sight is close to 90 deg) that the components periodically eclipse each other. Consequently, the observer finds changes of the apparent combined brightness of the system with the period coincident with that of the components' orbital motion. EA Algol (Beta Persei)-type eclipsing systems. Binaries with spherical or slightly ellipsoidal components. It is possible to specify, for their light curves, the moments of the beginning and end of the eclipses. Between eclipses the light remains almost constant or varies insignificantly because of reflection effects, slight ellipsoidality of components, or physical variations. Secondary minima may be absent. An extremely wide range of periods is observed, from 0.2 to >= 10000 days. Light amplitudes are also quite different and may reach several magnitudes. EB Beta Lyrae-type eclipsing systems. These are eclipsing systems having ellipsoidal components and light curves for which it is impossible to specify the exact times of onset and end of eclipses because of a continuous change of a system's apparent combined brightness between eclipses; secondary minimum is observed in all cases, its depth usually being considerably smaller than that of the primary minimum; periods are mainly longer than 1 day. The components generally belong to early spectral types (B-A). Light amplitudes are usually <2 mag in V. EW W Ursae Majoris-type eclipsing variables. These are eclipsers with periods shorter than 1 days, consisting of ellipsoidal components almost in contact and having light curves for which it is impossible to specify the exact times of onset and end of eclipses. The depths of the primary and secondary minima are almost equal or differ insignificantly. Light amplitudes are usually <0.8 mag in V. The components generally belong to spectral types F-G and later.
BCEP	Variables of the Beta Cephei type (Beta Cep, Beta CMa), which are pulsating O8-B6 I-V stars with periods of light and radial-velocity variations in the range of 0.1 - 0.6 days and light amplitudes from 0.01 to 0.3 mag in V. The light curves are similar in shape to average radial-velocity curves but lag in phase by a quarter of the period, so that maximum brightness corresponds to maximum contraction, i.e., to minimum stellar radius. The majority of these stars probably show radial pulsations, but some (V649 Per) display nonradial pulsations; multiperiodicity is characteristic of many of these stars.