Period length over time for Mira stars

These period diagrams is based on the O-C diagrams at http://var.saaf.se/mirainfooc.php and calculated with data from the organizations AAVSO, AFOEV, VSOLJ, BAAVSS and ASAS-SN and various published maxima. The diagrams shows the development over time of the stars mean period or cycle length.
The difference between the mean period and the period at a certain time can be calculated as the slope of an O-C diagram at that time. To get the O-C diagram more smooth and thus the period less jumpy a moving average O-C for each cycle was first calculated. The moving average is the mean of the O-C for the current cycle together with 3 O-C values before and after the current.
The period for cycle i was then calculated as: Mean period + (avg O-Ci+1 - avg O-Ci-1) / 2.

Each diagram is also clickable to get a table with the underlying data.



Constellations
And - CMi
Cap - Cyg
Del - Hyi
Ind - Ori
Pav - Vul



Andromeda
R And
Mean period: 409.73, Mean epoch: 2453811.4
GCVS period: 409.2, GCVS epoch: 2453820
GCVS spectral type: S3,5e-S8,8e(M7e)


T And
Mean period: 280.77, Mean epoch: 2450814.0
GCVS period: 281, GCVS epoch: 2450854
GCVS spectral type: M4e-M7.5e


U And
Mean period: 346.19, Mean epoch: 2449562.6
GCVS period: 347.7, GCVS epoch: 2449564
GCVS spectral type: M6e


V And
Mean period: 257.91, Mean epoch: 2451540.7
GCVS period: 256.4, GCVS epoch: 2451528
GCVS spectral type: M2e-M3e


W And
Mean period: 396.04, Mean epoch: 2448677.9
GCVS period: 397.3, GCVS epoch: 2448654
GCVS spectral type: S6,1e-S9,2e


X And
Mean period: 345.80, Mean epoch: 2449641.0
GCVS period: 343.4, GCVS epoch: 2449620
GCVS spectral type: S2,9e-S5,5e


Y And
Mean period: 220.89, Mean epoch: 2449502.2
GCVS period: 220.5, GCVS epoch: 2449489
GCVS spectral type: M3e-M4.5e


RR And
Mean period: 327.92, Mean epoch: 2449630.9
GCVS period: 330.6, GCVS epoch: 2449644
GCVS spectral type: S6.5,2e


RW And
Mean period: 429.99, Mean epoch: 2453383.8
GCVS period: 430, GCVS epoch: 2453360
GCVS spectral type: M5e-M10e(S6,2e)


RY And
Mean period: 392.51, Mean epoch: 2453409.1
GCVS period: 391.2, GCVS epoch: 2453400
GCVS spectral type: M8


SV And
Mean period: 315.46, Mean epoch: 2453253.5
GCVS period: 313, GCVS epoch: 2453220
GCVS spectral type: M5e-M7e


SX And
Mean period: 332.71, Mean epoch: 2453195.2
GCVS period: 332.8, GCVS epoch: 2453208
GCVS spectral type: M6.5e


SZ And
Mean period: 342.77, Mean epoch: 2453503.7
GCVS period: 344, GCVS epoch: 2453520
GCVS spectral type: M2e


TU And
Mean period: 317.18, Mean epoch: 2453667.0
GCVS period: 316.8, GCVS epoch: 2453700
GCVS spectral type: M5e


UW And
Mean period: 239.83, Mean epoch: 2454019.2
GCVS period: 237, GCVS epoch: 2454024
GCVS spectral type: M5


UZ And
Mean period: 314.60, Mean epoch: 2454001.2
GCVS period: 316, GCVS epoch: 2453990
GCVS spectral type: M7e


YZ And
Mean period: 207.54, Mean epoch: 2454092.3
GCVS period: 207, GCVS epoch: 2454092
GCVS spectral type: M5e


AX And
Mean period: 380.56, Mean epoch: 2451988.1
GCVS period: 378, GCVS epoch: 2451980
GCVS spectral type:


BG And
Mean period: 292.08, Mean epoch: 2454048.2
GCVS period: 289.5, GCVS epoch: 2454045
GCVS spectral type: S6.5,5e


BU And
Mean period: 382.57, Mean epoch: 2453624.3
GCVS period: 378, GCVS epoch: 2453585
GCVS spectral type: M7e


Antlia
V Ant
Mean period: 302.17, Mean epoch: 2452777.4
GCVS period: 303, GCVS epoch: 2452772
GCVS spectral type: M7IIIe


X Ant
Mean period: 161.90, Mean epoch: 2453450.2
GCVS period: 164.1, GCVS epoch: 2453458
GCVS spectral type: M2-M6e


Apus
T Aps
Mean period: 261.26, Mean epoch: 2441105.9
GCVS period: 261.03, GCVS epoch: 2441096
GCVS spectral type: M3e


Aquarius
R Aqr
Mean period: 386.77, Mean epoch: 2454013.6
GCVS period: 390, GCVS epoch: 2454045
GCVS spectral type: M5e-M8.5e+pec


S Aqr
Mean period: 279.26, Mean epoch: 2452080.7
GCVS period: 279.3, GCVS epoch: 2452107
GCVS spectral type: M4e-M6e


T Aqr
Mean period: 201.89, Mean epoch: 2453246.7
GCVS period: 201.1, GCVS epoch: 2453229
GCVS spectral type: M2e-M5.5e


W Aqr
Mean period: 380.58, Mean epoch: 2453953.1
GCVS period: 376.1, GCVS epoch: 2453940
GCVS spectral type: M6-M8e


X Aqr
Mean period: 311.60, Mean epoch: 2452948.2
GCVS period: 311.4, GCVS epoch: 2452951
GCVS spectral type: S6,3e:(M4e-M6.5e)


Y Aqr
Mean period: 381.76, Mean epoch: 2452262.4
GCVS period: 382.34, GCVS epoch: 2452240
GCVS spectral type: M6.5e-M9


RR Aqr
Mean period: 182.46, Mean epoch: 2453962.8
GCVS period: 182.45, GCVS epoch: 2453954
GCVS spectral type: M2e-M4e


RS Aqr
Mean period: 215.94, Mean epoch: 2453900.9
GCVS period: 221.3, GCVS epoch: 2454005
GCVS spectral type: M2e


Aquila
R Aql
Mean period: 299.40, Mean epoch: 2443167.0
GCVS period: 284.2, GCVS epoch: 2443458
GCVS spectral type: M5e-M9IIIe


W Aql
Mean period: 487.95, Mean epoch: 2439042.9
GCVS period: 490.43, GCVS epoch: 2439116
GCVS spectral type: S3,9e-S6,9e


X Aql
Mean period: 346.33, Mean epoch: 2441468.0
GCVS period: 347.04, GCVS epoch: 2441487
GCVS spectral type: M6e


Z Aql
Mean period: 129.44, Mean epoch: 2441945.6
GCVS period: 129.226, GCVS epoch: 2441938
GCVS spectral type: M3e


RR Aql
Mean period: 395.47, Mean epoch: 2441778.3
GCVS period: 394.78, GCVS epoch: 2441764
GCVS spectral type: M6e-M9


RS Aql
Mean period: 410.05, Mean epoch: 2439243.5
GCVS period: 410.12, GCVS epoch: 2439193
GCVS spectral type: M5e-M8


RT Aql
Mean period: 327.73, Mean epoch: 2443299.9
GCVS period: 327.11, GCVS epoch: 2443290
GCVS spectral type: M6e-M9p(S)


RU Aql
Mean period: 274.68, Mean epoch: 2439168.1
GCVS period: 274.24, GCVS epoch: 2439171
GCVS spectral type: M5e


RV Aql
Mean period: 218.55, Mean epoch: 2442621.2
GCVS period: 218.6, GCVS epoch: 2442618
GCVS spectral type: M2e-M7:e


SV Aql
Mean period: 252.41, Mean epoch: 2439123.5
GCVS period: 252.89, GCVS epoch: 2439170
GCVS spectral type: M8


SY Aql
Mean period: 355.80, Mean epoch: 2442651.1
GCVS period: 355.92, GCVS epoch: 2442651
GCVS spectral type: M5e-M7e


TU Aql
Mean period: 270.34, Mean epoch: 2442950.8
GCVS period: 270.39, GCVS epoch: 2442930
GCVS spectral type: M2e-M9


EU Aql
Mean period: 323.29, Mean epoch: 2427299.7
GCVS period: 321, GCVS epoch: 2427299
GCVS spectral type: M9


Ara
U Ara
Mean period: 225.11, Mean epoch: 2451983.3
GCVS period: 224.6, GCVS epoch: 2451981
GCVS spectral type: M3IIep


Aries
R Ari
Mean period: 186.82, Mean epoch: 2453649.5
GCVS period: 185.67, GCVS epoch: 2453640
GCVS spectral type: M3e-M6e


S Ari
Mean period: 292.49, Mean epoch: 2453698.1
GCVS period: 291, GCVS epoch: 2453710
GCVS spectral type: M4e-M5e


T Ari
Mean period: 320.53, Mean epoch: 2452536.6
GCVS period: 340, GCVS epoch: 2452600
GCVS spectral type: M6e-M8e


U Ari
Mean period: 371.83, Mean epoch: 2453652.1
GCVS period: 371.1, GCVS epoch: 2453658
GCVS spectral type: M4e-M7.5e


Auriga
R Aur
Mean period: 457.31, Mean epoch: 2444025.8
GCVS period: 457.51, GCVS epoch: 2444004
GCVS spectral type: M6.5e-M9.5e


U Aur
Mean period: 408.31, Mean epoch: 2443579.2
GCVS period: 408.09, GCVS epoch: 2443579
GCVS spectral type: M7e-M9e


V Aur
Mean period: 352.97, Mean epoch: 2443439.5
GCVS period: 353, GCVS epoch: 2443435
GCVS spectral type: C6,2e(N3e)


W Aur
Mean period: 273.76, Mean epoch: 2443151.5
GCVS period: 274.27, GCVS epoch: 2443165
GCVS spectral type: M3e-M8e


X Aur
Mean period: 164.17, Mean epoch: 2444645.1
GCVS period: 163.79, GCVS epoch: 2444604
GCVS spectral type: M3e-M7e


RR Aur
Mean period: 308.78, Mean epoch: 2443072.8
GCVS period: 307.87, GCVS epoch: 2443031
GCVS spectral type: M3e-M7e


RU Aur
Mean period: 468.79, Mean epoch: 2442597.8
GCVS period: 466.47, GCVS epoch: 2442520
GCVS spectral type: M7e-M9e


ST Aur
Mean period: 292.23, Mean epoch: 2438309.7
GCVS period: 291.94, GCVS epoch: 2438302
GCVS spectral type:


SZ Aur
Mean period: 455.52, Mean epoch: 2439068.8
GCVS period: 454.04, GCVS epoch: 2439048
GCVS spectral type: M8e


UV Aur
Mean period: 393.83, Mean epoch: 2441064.9
GCVS period: 394.42, GCVS epoch: 2441062
GCVS spectral type: C6,2-C8,2Jep(Ne)


VX Aur
Mean period: 325.17, Mean epoch: 2438799.1
GCVS period: 322.25, GCVS epoch: 2438673
GCVS spectral type: M5e


VY Aur
Mean period: 399.97, Mean epoch: 2438050.9
GCVS period: 402.1, GCVS epoch: 2438122
GCVS spectral type: M8e


AA Aur
Mean period: 266.98, Mean epoch: 2442936.1
GCVS period: 270.17, GCVS epoch: 2442907
GCVS spectral type: M3e


AZ Aur
Mean period: 415.53, Mean epoch: 2442869.6
GCVS period: 415.92, GCVS epoch: 2442866
GCVS spectral type: C7,1e-C8,2-3(N0e)


GQ Aur
Mean period: 305.07, Mean epoch: 2443925.4
GCVS period: 304.75, GCVS epoch: 2443918
GCVS spectral type: M3


Bootes
R Boo
Mean period: 223.50, Mean epoch: 2444526.9
GCVS period: 223.4, GCVS epoch: 2444518
GCVS spectral type: M3e-M8e


S Boo
Mean period: 271.08, Mean epoch: 2444150.0
GCVS period: 270.73, GCVS epoch: 2444116
GCVS spectral type: M3e-M6e


Z Boo
Mean period: 280.93, Mean epoch: 2441080.6
GCVS period: 281.14, GCVS epoch: 2441096
GCVS spectral type: M5e-M6e


RR Boo
Mean period: 194.74, Mean epoch: 2443043.0
GCVS period: 194.7, GCVS epoch: 2443047
GCVS spectral type: M2e-M6e


RT Boo
Mean period: 272.51, Mean epoch: 2442651.4
GCVS period: 273.86, GCVS epoch: 2442722
GCVS spectral type: M6.5e-M8e


Caelum
R Cae
Mean period: 391.99, Mean epoch: 2440709.3
GCVS period: 390.95, GCVS epoch: 2440645
GCVS spectral type: M6e-M9e


Camelopardalis
R Cam
Mean period: 270.30, Mean epoch: 2443965.0
GCVS period: 270.22, GCVS epoch: 2443978
GCVS spectral type: S2,8e-S8,7e


T Cam
Mean period: 373.91, Mean epoch: 2443456.8
GCVS period: 373.2, GCVS epoch: 2443433
GCVS spectral type: S4,7e-S8.5,8e


V Cam
Mean period: 522.62, Mean epoch: 2443385.3
GCVS period: 522.45, GCVS epoch: 2443402
GCVS spectral type: M7e


W Cam
Mean period: 284.37, Mean epoch: 2435164.9
GCVS period: 283.6, GCVS epoch: 2435213
GCVS spectral type: M7


X Cam
Mean period: 143.70, Mean epoch: 2444670.0
GCVS period: 143.56, GCVS epoch: 2444679
GCVS spectral type: K8-M8e


RT Cam
Mean period: 365.67, Mean epoch: 2443798.1
GCVS period: 366.31, GCVS epoch: 2443837
GCVS spectral type: M6e


SU Cam
Mean period: 285.16, Mean epoch: 2444272.4
GCVS period: 285.03, GCVS epoch: 2444265
GCVS spectral type: M5


SW Cam
Mean period: 254.77, Mean epoch: 2443403.2
GCVS period: 252.8, GCVS epoch: 2443419
GCVS spectral type: M5e


UZ Cam
Mean period: 232.46, Mean epoch: 2443837.0
GCVS period: 225.64, GCVS epoch: 2443773
GCVS spectral type: M3


Cancer
R Cnc
Mean period: 361.88, Mean epoch: 2444226.1
GCVS period: 361.6, GCVS epoch: 2444231
GCVS spectral type: M6e-M9e


U Cnc
Mean period: 304.99, Mean epoch: 2440649.8
GCVS period: 304.78, GCVS epoch: 2440627
GCVS spectral type: M2e


V Cnc
Mean period: 272.13, Mean epoch: 2443488.6
GCVS period: 272.13, GCVS epoch: 2443485
GCVS spectral type: S0e-S7,9e


W Cnc
Mean period: 393.43, Mean epoch: 2443875.3
GCVS period: 393.22, GCVS epoch: 2443896
GCVS spectral type: M6.5e-M9e


RR Cnc
Mean period: 298.35, Mean epoch: 2441399.8
GCVS period: 298.26, GCVS epoch: 2441400
GCVS spectral type: M3e


Canes Venatici
R CVn
Mean period: 328.59, Mean epoch: 2443574.3
GCVS period: 328.53, GCVS epoch: 2443586
GCVS spectral type: M6e-M9e


T CVn
Mean period: 290.29, Mean epoch: 2442755.8
GCVS period: 290.09, GCVS epoch: 2442784
GCVS spectral type: M6.5e


U CVn
Mean period: 345.55, Mean epoch: 2442458.2
GCVS period: 345.65, GCVS epoch: 2442491
GCVS spectral type: M7e


RT CVn
Mean period: 253.78, Mean epoch: 2434408.4
GCVS period: 253.6, GCVS epoch: 2434400
GCVS spectral type: M5e


Canis Minor
R CMi
Mean period: 337.70, Mean epoch: 2441317.9
GCVS period: 337.78, GCVS epoch: 2441323
GCVS spectral type: C0ev


S CMi
Mean period: 333.07, Mean epoch: 2443876.9
GCVS period: 332.94, GCVS epoch: 2443911
GCVS spectral type: M6e-M8e


T CMi
Mean period: 320.44, Mean epoch: 2441944.2
GCVS period: 328.3, GCVS epoch: 2442045
GCVS spectral type: M4Se-M8


U CMi
Mean period: 411.51, Mean epoch: 2443147.0
GCVS period: 413.88, GCVS epoch: 2443150
GCVS spectral type: M4e


V CMi
Mean period: 366.30, Mean epoch: 2442752.0
GCVS period: 366.1, GCVS epoch: 2442737
GCVS spectral type: M4e-M10