Mira
68 Cet
Observable Variable Star
Showpiece (76/100)
Range: 2.0 - 10.1, Period: 332.0d, Type: M
HIP 10826; 68 Cet
VariableStar
Cet
Visible
Level 1
Naked eye / Binoculars - Monitor brightness changes
Physical Properties
Magnitude
3.04
Range
2.0 - 10.1
Period
332.000 days
Variable Type
Mira (Long-period Pulsating)
Spectral Type
M5/6 IIIe
Star Color
Red
(B-V 1.42)
Temperature
2943 K
Radius
370.1 R☉
Distance
418.5 ly
Position & Identifiers
RA
02h 19m 20.7s
Dec
-02° 58' 39.0"
Constellation
Cet
HR
681
HIP
10826
Flamsteed
68 Cet
Variable ID
Omi Cet
Double Cat
1778
Querying VizieR catalog...
Visibility
Set a location in User Settings to see visibility data.
Light Curve
Comparison Stars for Mira (2.0–10.1)
Nearby stable stars for estimating brightness (AAVSO)
Loading comparison stars…
Multiple Star System
Components
4
Component IDs
AC
Separation
71.5″
Companion Mag
14.1
Position Angle
68°
Star Colors
A: Red
Discoverer
BU 1371
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
Sep: 71.5″ · PA: 68° · N up, E left
Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 3.1″
Size Comparison
Stellar Lifecycle
Spectral Classification
Hertzsprung-Russell Diagram
Loading HR diagram…
Blackbody Spectrum
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
Stellar Notes
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.
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.
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.
Stratoscope II observations indicate infrared H2O bands. SiO maser source. Technetium found in spectrum. Also | classified M5e-M9e.
0.0058". Masses A 15.7, P 4.0 solar.
MIRA.
Survey Image
Loading survey image…