Mira
catalogues and names
catalogues and names | Mira, o Cet, omi Cet, 68 Cet, HR 681, HD 14386, SAO 129825, BD -3 353, WDS 02193-0259Aa |
constellation | Cetus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
note (category: star names): | MIRA. |
position, motion, parallax:
position (J2000) | RA: 2h 19min 20.7sec | DEC: -2° 58' 39'' | ||
position (2000.72) | RA: 2h 19min 23sec | DEC: -2° 58' 27'' | ||
position (B1900) | 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 |
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trigonometric parallax | 0.024 arcsec | |||
galactic coordinates | longitude: 167.75° | latitude: -57.98° |
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 | |
IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
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 |
position (2000.72) | RA: 2h 19min 23sec | DEC: -2° 58' 28'' | JD: 2451806.35 | |
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 arcsec | ±0.002 arcsec | source: 25 | |
galactic coord. (B1950) | longitude: 167.76° | latitude: -57.98° |
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:
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:
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 (B1950) | RA: 2h 16min 49.045sec | DEC: -3° 12' 13.39'' | ±0.009 arcsec |
position (2000.72) | RA: 2h 19min 23sec | DEC: -2° 58' 16'' | JD: 2451806.35 |
position (J2000) | RA: 2h 19min 20.729sec | DEC: -2° 58' 39.42'' | |
proper motion B1950 (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 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
position (B1900) | RA: 2h 14.3min | DEC: -3° 26' |
magnitudes, spectral classes, orbital elements:
author: | P. Baize |
date of observation: | 1976 |
spectral class component B: | gM7e |
spectral class component B: | gM7e |
period [y]: | 400 |
semi-major axis [arcsec]: | 0.85 |
inclination [deg]: | 111.3 |
node [deg]: | 118.5 |
eccentricity: | 0.66 |
time of periastron passage: | 2001.5 |
dates of ephemeris: | 1975-2000 |
grade: | indeterminate |
reference: | Astron. Astrophys. Suppl. 39, 83; 1980. |
notes | The primary is Mira Ceti. The companion is probably also variable. |