Period length over time for Mira stars

These period diagrams is based on the O-C diagrams at http://var.astronet.se/mirainfooc.php and calculated with data from the organizations AAVSO, AFOEV, VSOLJ and BAAVSS 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: 409.71, Mean epoch: 2453810.0
GCVS period: 409.2, GCVS epoch: 2453820
GCVS spectral type: S3,5e-S8,8e(M7e)


T And
Mean period: 280.80, Mean epoch: 2450816.3
GCVS period: 281, GCVS epoch: 2450854
GCVS spectral type: M4e-M7.5e


U And
Mean period: 346.25, Mean epoch: 2449566.6
GCVS period: 347.7, GCVS epoch: 2449564
GCVS spectral type: M6e


V And
Mean period: 257.88, Mean epoch: 2451538.2
GCVS period: 256.4, GCVS epoch: 2451528
GCVS spectral type: M2e-M3e


W And
Mean period: 395.98, Mean epoch: 2448674.9
GCVS period: 397.3, GCVS epoch: 2448654
GCVS spectral type: S6,1e-S9,2e


X And
Mean period: 345.77, Mean epoch: 2449639.2
GCVS period: 343.4, GCVS epoch: 2449620
GCVS spectral type: S2,9e-S5,5e


Y And
Mean period: 220.83, Mean epoch: 2449496.2
GCVS period: 220.5, GCVS epoch: 2449489
GCVS spectral type: M3e-M4.5e


RR And
Mean period: 327.92, Mean epoch: 2449630.7
GCVS period: 330.6, GCVS epoch: 2449644
GCVS spectral type: S6.5,2e


RW And
Mean period: 429.96, Mean epoch: 2453382.2
GCVS period: 430, GCVS epoch: 2453360
GCVS spectral type: M5e-M10e(S6,2e)


RY And
Mean period: 392.65, Mean epoch: 2453416.1
GCVS period: 391.2, GCVS epoch: 2453400
GCVS spectral type: M8


SV And
Mean period: 315.54, Mean epoch: 2453259.0
GCVS period: 313, GCVS epoch: 2453220
GCVS spectral type: M5e-M7e


SX And
Mean period: 332.73, Mean epoch: 2453195.7
GCVS period: 332.8, GCVS epoch: 2453208
GCVS spectral type: M6.5e


SZ And
Mean period: 342.82, Mean epoch: 2453506.1
GCVS period: 344, GCVS epoch: 2453520
GCVS spectral type: M2e


TU And
Mean period: 317.24, Mean epoch: 2453672.2
GCVS period: 316.8, GCVS epoch: 2453700
GCVS spectral type: M5e


UW And
Mean period: 239.87, Mean epoch: 2454023.1
GCVS period: 237, GCVS epoch: 2454024
GCVS spectral type: M5


UZ And
Mean period: 314.42, Mean epoch: 2453989.0
GCVS period: 316, GCVS epoch: 2453990
GCVS spectral type: M7e


YZ And
Mean period: 207.57, Mean epoch: 2454095.7
GCVS period: 207, GCVS epoch: 2454092
GCVS spectral type: M5e


AX And
Mean period: 380.64, Mean epoch: 2451990.5
GCVS period: 378, GCVS epoch: 2451980
GCVS spectral type:


BG And
Mean period: 291.03, Mean epoch: 2454049.2
GCVS period: 289.5, GCVS epoch: 2454045
GCVS spectral type: S6.5,5e


BU And
Mean period: 382.25, Mean epoch: 2453613.6
GCVS period: 378, GCVS epoch: 2453585
GCVS spectral type: M7e


Apus
T Aps
Mean period: 261.24, Mean epoch: 2441105.4
GCVS period: 261.03, GCVS epoch: 2441096
GCVS spectral type: M3e


Aquarius
R Aqr
Mean period: 386.74, Mean epoch: 2454010.9
GCVS period: 390, GCVS epoch: 2454045
GCVS spectral type: M5e-M8.5e+pec


S Aqr
Mean period: 279.20, Mean epoch: 2452074.9
GCVS period: 279.3, GCVS epoch: 2452107
GCVS spectral type: M4e-M6e


T Aqr
Mean period: 201.87, Mean epoch: 2453243.5
GCVS period: 201.1, GCVS epoch: 2453229
GCVS spectral type: M2e-M5.5e


W Aqr
Mean period: 380.64, Mean epoch: 2453957.1
GCVS period: 376.1, GCVS epoch: 2453940
GCVS spectral type: M6-M8e


X Aqr
Mean period: 311.61, Mean epoch: 2452948.9
GCVS period: 311.4, GCVS epoch: 2452951
GCVS spectral type: S6,3e:(M4e-M6.5e)


Y Aqr
Mean period: 381.68, Mean epoch: 2452257.4
GCVS period: 382.34, GCVS epoch: 2452240
GCVS spectral type: M6.5e-M9


RR Aqr
Mean period: 182.44, Mean epoch: 2453960.9
GCVS period: 182.45, GCVS epoch: 2453954
GCVS spectral type: M2e-M4e


RS Aqr
Mean period: 215.70, Mean epoch: 2453874.5
GCVS period: 221.3, GCVS epoch: 2454005
GCVS spectral type: M2e


Aquila
R Aql
Mean period: 301.39, Mean epoch: 2443300.2
GCVS period: 284.2, GCVS epoch: 2443458
GCVS spectral type: M5e-M9e


W Aql
Mean period: 488.06, Mean epoch: 2439045.6
GCVS period: 490.43, GCVS epoch: 2439116
GCVS spectral type: S3,9e-S6,9e


X Aql
Mean period: 346.41, Mean epoch: 2441471.5
GCVS period: 347.04, GCVS epoch: 2441487
GCVS spectral type: M6e


Z Aql
Mean period: 129.48, Mean epoch: 2441949.2
GCVS period: 129.226, GCVS epoch: 2441938
GCVS spectral type: M3e


RR Aql
Mean period: 395.25, Mean epoch: 2441771.5
GCVS period: 394.78, GCVS epoch: 2441764
GCVS spectral type: M6e-M9


RS Aql
Mean period: 409.59, Mean epoch: 2439232.3
GCVS period: 410.12, GCVS epoch: 2439193
GCVS spectral type: M5e-M8


RT Aql
Mean period: 327.78, Mean epoch: 2443302.2
GCVS period: 327.11, GCVS epoch: 2443290
GCVS spectral type: M6e-M8e(S)


RU Aql
Mean period: 274.65, Mean epoch: 2439167.1
GCVS period: 274.24, GCVS epoch: 2439171
GCVS spectral type: M5e


RV Aql
Mean period: 218.62, Mean epoch: 2442625.0
GCVS period: 218.6, GCVS epoch: 2442618
GCVS spectral type: M2e-M7:e


SV Aql
Mean period: 252.44, Mean epoch: 2439124.6
GCVS period: 252.89, GCVS epoch: 2439170
GCVS spectral type: M8


SY Aql
Mean period: 355.72, Mean epoch: 2442647.8
GCVS period: 355.92, GCVS epoch: 2442651
GCVS spectral type: M5e-M7e


TU Aql
Mean period: 270.36, Mean epoch: 2442951.4
GCVS period: 270.39, GCVS epoch: 2442930
GCVS spectral type: M4-M9


EU Aql
Mean period: 325.05, Mean epoch: 2427184.4
GCVS period: 321, GCVS epoch: 2427299
GCVS spectral type: M9


Ara
U Ara
Mean period: 225.12, Mean epoch: 2451984.5
GCVS period: 224.6, GCVS epoch: 2451981
GCVS spectral type: M3IIep


Aries
R Ari
Mean period: 186.83, Mean epoch: 2453650.6
GCVS period: 185.67, GCVS epoch: 2453640
GCVS spectral type: M3e-M6e


S Ari
Mean period: 292.46, Mean epoch: 2453695.2
GCVS period: 291, GCVS epoch: 2453710
GCVS spectral type: M4e-M5e


T Ari
Mean period: 320.51, Mean epoch: 2452534.2
GCVS period: 340, GCVS epoch: 2452600
GCVS spectral type: M6e-M8e


U Ari
Mean period: 371.80, Mean epoch: 2453650.2
GCVS period: 371.1, GCVS epoch: 2453658
GCVS spectral type: M4e-M7.5e


Auriga
R Aur
Mean period: 457.34, Mean epoch: 2444026.6
GCVS period: 457.51, GCVS epoch: 2444004
GCVS spectral type: M6.5e-M9.5e


U Aur
Mean period: 408.50, Mean epoch: 2443586.4
GCVS period: 408.09, GCVS epoch: 2443579
GCVS spectral type: M7e-M9e


V Aur
Mean period: 352.87, Mean epoch: 2443435.1
GCVS period: 353, GCVS epoch: 2443435
GCVS spectral type: C6,2e(N3e)


W Aur
Mean period: 273.81, Mean epoch: 2443154.1
GCVS period: 274.27, GCVS epoch: 2443165
GCVS spectral type: M3e-M8e


X Aur
Mean period: 164.12, Mean epoch: 2444639.9
GCVS period: 163.79, GCVS epoch: 2444604
GCVS spectral type: M3e-M7e


RR Aur
Mean period: 308.71, Mean epoch: 2443072.5
GCVS period: 307.87, GCVS epoch: 2443031
GCVS spectral type: M3e-M7e


RU Aur
Mean period: 469.05, Mean epoch: 2442596.3
GCVS period: 466.47, GCVS epoch: 2442520
GCVS spectral type: M7e-M9e


ST Aur
Mean period: 292.01, Mean epoch: 2438306.6
GCVS period: 291.94, GCVS epoch: 2438302
GCVS spectral type:


SZ Aur
Mean period: 455.46, Mean epoch: 2439069.1
GCVS period: 454.04, GCVS epoch: 2439048
GCVS spectral type: M8e


UV Aur
Mean period: 393.73, Mean epoch: 2441064.5
GCVS period: 394.42, GCVS epoch: 2441062
GCVS spectral type: C6,2-C8,2Jep(Ne)


VX Aur
Mean period: 325.32, Mean epoch: 2438808.1
GCVS period: 322.25, GCVS epoch: 2438673
GCVS spectral type: M5e


VY Aur
Mean period: 398.85, Mean epoch: 2438076.0
GCVS period: 402.1, GCVS epoch: 2438122
GCVS spectral type: M8e


AA Aur
Mean period: 266.75, Mean epoch: 2442927.0
GCVS period: 270.17, GCVS epoch: 2442907
GCVS spectral type: M3e


AZ Aur
Mean period: 415.38, Mean epoch: 2442868.8
GCVS period: 415.92, GCVS epoch: 2442866
GCVS spectral type: C7,1e-C8,2-3(N0e)


GQ Aur
Mean period: 304.97, Mean epoch: 2443920.2
GCVS period: 304.75, GCVS epoch: 2443918
GCVS spectral type: M3


Bootes
R Boo
Mean period: 223.49, Mean epoch: 2444525.2
GCVS period: 223.4, GCVS epoch: 2444518
GCVS spectral type: M3e-M8e


S Boo
Mean period: 271.09, Mean epoch: 2444151.0
GCVS period: 270.73, GCVS epoch: 2444116
GCVS spectral type: M3e-M6e


Z Boo
Mean period: 280.96, Mean epoch: 2441080.8
GCVS period: 281.14, GCVS epoch: 2441096
GCVS spectral type: M5e-M6e


RR Boo
Mean period: 194.75, Mean epoch: 2443044.2
GCVS period: 194.7, GCVS epoch: 2443047
GCVS spectral type: M2e-M6e


RT Boo
Mean period: 272.47, Mean epoch: 2442652.2
GCVS period: 273.86, GCVS epoch: 2442722
GCVS spectral type: M6.5e-M8e


Caelum
R Cae
Mean period: 391.91, Mean epoch: 2440706.9
GCVS period: 390.95, GCVS epoch: 2440645
GCVS spectral type: M6e


Camelopardalis
R Cam
Mean period: 270.32, Mean epoch: 2443967.0
GCVS period: 270.22, GCVS epoch: 2443978
GCVS spectral type: S2,8e-S8,7e


T Cam
Mean period: 373.85, Mean epoch: 2443454.5
GCVS period: 373.2, GCVS epoch: 2443433
GCVS spectral type: S4,7e-S8.5,8e


V Cam
Mean period: 522.87, Mean epoch: 2443389.6
GCVS period: 522.45, GCVS epoch: 2443402
GCVS spectral type: M7e


W Cam
Mean period: 280.93, Mean epoch: 2435357.8
GCVS period: 283.6, GCVS epoch: 2435213
GCVS spectral type: M7


X Cam
Mean period: 143.72, Mean epoch: 2444671.7
GCVS period: 143.56, GCVS epoch: 2444679
GCVS spectral type: K8-M8e


RT Cam
Mean period: 365.78, Mean epoch: 2443801.7
GCVS period: 366.31, GCVS epoch: 2443837
GCVS spectral type: M6e


SU Cam
Mean period: 285.06, Mean epoch: 2444270.8
GCVS period: 285.03, GCVS epoch: 2444265
GCVS spectral type: M5


SW Cam
Mean period: 254.59, Mean epoch: 2443409.2
GCVS period: 252.8, GCVS epoch: 2443419
GCVS spectral type: M5e


Cancer
R Cnc
Mean period: 361.91, Mean epoch: 2444228.0
GCVS period: 361.6, GCVS epoch: 2444231
GCVS spectral type: M6e-M9e


U Cnc
Mean period: 304.93, Mean epoch: 2440645.7
GCVS period: 304.78, GCVS epoch: 2440627
GCVS spectral type: M2e


V Cnc
Mean period: 272.13, Mean epoch: 2443488.9
GCVS period: 272.13, GCVS epoch: 2443485
GCVS spectral type: S0e-S7,9e


W Cnc
Mean period: 393.66, Mean epoch: 2443884.6
GCVS period: 393.22, GCVS epoch: 2443896
GCVS spectral type: M6.5e-M9e


RR Cnc
Mean period: 298.48, Mean epoch: 2441405.0
GCVS period: 298.26, GCVS epoch: 2441400
GCVS spectral type: M3e


Canes Venatici
R CVn
Mean period: 328.53, Mean epoch: 2443571.5
GCVS period: 328.53, GCVS epoch: 2443586
GCVS spectral type: M5.5e-M9e


T CVn
Mean period: 289.97, Mean epoch: 2442741.7
GCVS period: 290.09, GCVS epoch: 2442784
GCVS spectral type: M6.5e


U CVn
Mean period: 345.70, Mean epoch: 2442464.1
GCVS period: 345.65, GCVS epoch: 2442491
GCVS spectral type: M7e


RT CVn
Mean period: 253.80, Mean epoch: 2434409.7
GCVS period: 253.6, GCVS epoch: 2434400
GCVS spectral type: M5e


Canis Minor
R CMi
Mean period: 337.69, Mean epoch: 2441317.4
GCVS period: 337.78, GCVS epoch: 2441323
GCVS spectral type: C7,1Je(CSep)


S CMi
Mean period: 333.06, Mean epoch: 2443876.1
GCVS period: 332.94, GCVS epoch: 2443911
GCVS spectral type: M6e-M8e


T CMi
Mean period: 320.31, Mean epoch: 2441937.9
GCVS period: 328.3, GCVS epoch: 2442045
GCVS spectral type: M4Se-M8


U CMi
Mean period: 411.41, Mean epoch: 2443143.2
GCVS period: 413.88, GCVS epoch: 2443150
GCVS spectral type: M4e


V CMi
Mean period: 366.28, Mean epoch: 2442750.6
GCVS period: 366.1, GCVS epoch: 2442737
GCVS spectral type: M4e-M10