Mira


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. The Washington Visual Double Star Catalog, 1996.0

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


catalogues and names Mira, o Cet, omi Cet, 68 Cet, HR 681, HD 14386, SAO 129825, WDS 02193-0259Aa
constellation Cetus

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

note (category: star names): MIRA.

object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

position, motion, parallax:

position (J2000) RA: 2h 19min 20,7sec DEC: -2 58' 39''
position (J1900) RA: 2h 14min 17,6sec DEC: -3 25' 54''
proper motion (J2000) RA: -0,008 arcsec/a DEC: -0,237 arcsec/a
radial velocity 64 km/s
note: variable radial velocity
trigonometric parallax 0,024 arcsec
note (category: dynamical parallaxes): 0.0058". Masses A 15.7, P 4.0 solar.

magnitude

visual magnitude 3,04
(V on UBV Johnson system)

spectral / color information

spectral class M7IIIe+Bep
B-V-magnitude 1,42
U-B-magnitude 1,09
R-I-magnitude 1,9
note (category: spectra): Stratoscope II observations indicate infrared H2O bands. SiO maser source. Technetium found in spectrum. Also classified M5e-M9e.
note (category: colors): The tabulated magnitude and colors refer to a time near maximum. Another determination at 6.99V gives B-V +1.56, U-B +0.12, R-I +3.08.

variability information

variable star identification Omi Cet
note (category: variability): Two variables: Mira and VZ Cet. Mira, ADS 1778A, M 2.0 - 10.1v, 331.96d; var. CO emission from circumstellar envelope. Speckle interferometry indicates large abrupt variation of diameter as a function of wavelength. Hydrogen lines vary on time scale of 1-2 days. Mira was discovered to be variable by Fabricius in 1596, the first such variable discovered. ADS 1778P, Ne "Novoides" class, VZ Cet, 9.5 - 12.0v, dBe.

double/multiple star system information

number of components of multiple star system 4
separation 118,7 arcsec
mag difference (of double or brightest multiple) 7,3
component ID AC
note (category: double and multiple data): AP var. M7IIIe, var. dBe, 400y, a = 0.85". The faint companion was first predicted in 1920 by Joy on the basis of a slightly displaced blue secondary spectrum. First seen by Aitken in 1923. Visible only when Mira is faint. Light variations on scale of hours superimposed by variations of 10-15 min. and rare flares of 2 min. duration. Components B, 13v at 73" and C, optical.

miscellaneous information

note (category: polarization): Polarization possibly due to circumstellar dust scattering.

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

position, motion, parallax:

position (J2000) RA: 2h 19min 20,787sec DEC: -2 58' 39,68'' 0,35 arcsec source: 17
proper motion (J2000) RA: 0,0001 arcsec/a DEC: -0,24 arcsec/a source: 25
radial velocity 64 km/s source: 25
trigonometric parallax 0,024 0,002 arcsec source: 25
galactic coord. (B1950) longitude: 167,76 latitude: -57,98
GCI unit vector (J2000) X: 0,819676 Y: 0,570467 Z: -0,051947

magnitude:

visual 3,04 (observed) source: 25

spectral information:

spectral class M0 source: 96
Morgan-Keenan M5.5-9IIIe+Bep source: 25
B-magnitude 4,46 0,2 B-V-magnitude 1,42
U-magnitude 5,55 0,2 U-B-magnitude 1,09

variability information:

source of data: 30
variability type 180
var. amplitude 8,1
var. period 331,96
var. epoch 2444839
22. August 1981, 12:00:00 UT
next max light 2451810,16
22. September 2000, 15:50:24 UT

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 0,5 arcsec
position angle 116

component magnitude spectral class catalogue(s)/name(s)
A 3,04 M0 Mira, o Ceti, 68 Cet, HR 681, HD 14386, SAO 129825
B 9,33 M0

sources:

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 (J1950) RA: 2h 16min 49,045sec DEC: -3 12' 13,39'' 0,009 arcsec
position (J2000) RA: 2h 19min 20,729sec DEC: -2 58' 39,42''
proper motion J1950 (FK4) RA: -0,0008 arcsec/a DEC: -0,233 arcsec/a 0,002 arcsec/a in RA
0,002 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,0005 arcsec/a DEC: -0,237 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 2 (accuracy: 1 decimal)
source of visual magnitude data Source cited in source catalog introduction.

spectral information:

spectral class M5e
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

catalogues

source catalogue GC, catalogue number: 2796
Durchmusterung BD-03 353
Boss General Catalogue 2796
Henry Draper Catalogue 14386

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

position and proper motion:

position (J2000) RA: 2h 19,3min DEC: -2 59'
proper motion (J2000) RA: 0,002 arcsec/a DEC: -0,24 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 1923 62 132 0,9'' - 9,6 M7IIIe JOY 1
1993 116 0,5''
Aa-B 1878 - 90 74,7'' - 13 - BU 1371
1911 85 73,1''
Aa-C 1782 18 92 114,6'' - 9,3 - H 1
1925 78 118,7''
Aa-D 1921 2 318 148,3'' - 9,3 - STG 1
BC 1911 1 69 45,5'' 13 9,3 - H 1

discoverer information:

discoverer code discoverer reference
JOY 1 - -
BU 1371 Burnham, S.W. -
H 1 Herschel, W. (Mem. R. Astron. Soc. 35, 21; 1867.)
STG 1 Struve, G. -

notes:

note Omicron Ceti. Prototype of the Mira-type variables. "Orbits" have been computed for the visual pair, but are most likely false. All distant companions are optical. B is a Cepheid, VZ Cet. H VI 1. C is BD-03@355.

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

position:

position (J1950) RA: 2h 16min 49sec DEC: -3 12' 13''

variability informations:

variability type M pulsating variable star
magnitute at max. brightness 2
magnitute at min. brightness 10,1
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2444839
22. August 1981, 12:00:00 UT
period [d] 331,96
next maximum light [JD] 2451810,16
22. September 2000, 15:50:24 UT
rising time 38 % of period

spectral information

spectral class M5e-M9e

references

to a study the main characteristics of the star was determined by the authors themselves
to a chart/photograph Vol. I GCVS (see Kholopov et al. 1985-1988)

miscanellous

ID in the GCVS catalogue 21/9015
constellation Cetus
notes on existence The star is equivalent to '0220001 R'.
There are notes in published catalog.

variability type description

variability type description
M Mira (Omicron) Ceti-type variables. These are long-period variable giants with characteristic late-type emission spectra (Me, Ce, Se) and light amplitudes from 2.5 to 11 mag in V. Their periodicity is well pronounced, and the periods lie in the range between 80 and 1000 days. Infrared amplitudes are usually less than in the visible and may be <2.5 mag. For example, in the K band they
usually do not exceed 0.9 mag. If the amplitudes exceed 1 - 1.5 mag , but it is not certain that the true light amplitude exceeds 2.5 mag, the symbol "M" is followed by a colon, or the star is attributed to the semiregular class with a colon following the symbol for that type (SR).