iiinova — where your digital self keeps evolving

Thomas Karlsson @thomaskarlsson.bsky.social · 22/09/2026

R CVn is a fairly ordinary Mira variable with a period of 300 days. Historically, the period has varied between 322 and 336 days. The star was discovered in 1888 by Thomas Espin. The phase diagram shows visual observations made within SAAF since 1990.

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Thomas Karlsson @thomaskarlsson.bsky.social · 14/09/2026

Berkeley Earth global temp. to August 2026 + trend forward, compared to 1850-1900. Current temperature: 1.45 (August 1.71) Rate of increase: 1970-2026: 0.21 deg/decade 1970-2009: 0.19 2010-2026: 0.36 2015-2026: 0.31 With current trend, 1.5 degrees will be reached in 2028, 2.0 in 2044.

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Thomas Karlsson @thomaskarlsson.bsky.social · 07/09/2026

MetOffice HadCRUT5 global temp. to July 2026 + trend forward, compared to 1850-1900. Current temperature: 1.43 (July 1.45) Rate of increase: 1970-2026: 0.20 deg/decade 1970-2009: 0.19 2010-2026: 0.32 2015-2026: 0.26 With current trend, 1.5 degrees will be reached in 2029, 2.0 in 2047.

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Thomas Karlsson @thomaskarlsson.bsky.social · 04/09/2026

From my database of maxima for mira variables. T Cep is on my list of meandering miras. It is a long-period mira where its period has varied between 375 and 401 days with a cycle of about 60 years. The star was discovered in 1878 by Vitold Ceraski More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 28/08/2026

IY Dra is a mira among SAAF's 50 forgotten miras. It is a fairly new mira, discovered by Kesao Takamizawa in 1998. Before SAAF began observing it, it had no known period. From our data, the period has now been determined to be 373.8 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 15/08/2026

MetOffice HadCRUT5 global temp. to June 2026 + trend forward, compared to 1850-1900. Current temperature: 1.42 (June 1.42) Rate of increase: 1970-2026: 0.20 deg/decade 1970-2009: 0.19 2010-2026: 0.32 2015-2026: 0.26 With current trend, 1.5 degrees will be reached in 2029, 2.0 in 2047.

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Thomas Karlsson @thomaskarlsson.bsky.social · 13/08/2026

Berkeley Earth global temp. to July 2026 + trend forward, compared to 1850-1900. Current temperature: 1.47 (July 1.56) Rate of increase: 1970-2026: 0.21 deg/decade 1970-2009: 0.19 2010-2026: 0.36 2015-2026: 0.30 With current trend, 1.5 degrees will be reached in 2027, 2.0 in 2044.

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Thomas Karlsson @thomaskarlsson.bsky.social · 11/08/2026

R And is a classic mira and has been observed by SAAF/V for a long time. Here is a phase diagram with our observations since 1971. The average period from our data is 409.74 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 02/08/2026

From my database of maxima for mira variables. R Nor is on my list of miras with period changes. R Nor is special in several ways. It is one of the few that has double maxima, and it has both a meandering and increasing period. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 24/07/2026

AM Dra is one of the brightest mira among the SAAF's collection of 50 forgotten miras. The brightness of our observations varies between magnitude 9.3 and 16.6 and with a period of 329.1 days. The star was discovered in 1955 by Edward H. Geyer at the Bamberg Observatory.

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Thomas Karlsson @thomaskarlsson.bsky.social · 16/07/2026

Berkeley Earth global temperature to June 2026 + trend forward, compared to 1850-1900. Current temperature: 1.47 (June 1.49) Rate of increase: 1970-2026: 0.21 deg/decade 1970-2009: 0.19 2010-2026: 0.36 2015-2026: 0.30 With current trend, 1.5 degrees will be reached in 2028, 2.0 in 2044.

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Thomas Karlsson @thomaskarlsson.bsky.social · 04/07/2026

MetOffice HadCRUT5 global temperature to May 2026 + trend forward, compared to 1850-1900. Current temperature: 1.42 (May 1.37) Rate of increase: 1970-2026: 0.20 deg/decade 1970-2009: 0.19 2010-2026: 0.32 2015-2026: 0.26 With current trend, 1.5 degrees will be reached in 2029, 2.0 in 2047.

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Thomas Karlsson @thomaskarlsson.bsky.social · 01/07/2026

R Ari is a short-period mira discovered by Friedrich Wilhelm Argelander in 1857. Here is a phase diagram with SAAF/V observations since 1990, with my observations in yellow. Based on our data, its period is calculated to be 186.45 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 23/06/2026

From my database of maxima for mira variables. S Sex is the brightest mira in Sextans. It is also on my list of meandering miras. Since 1890 its period has varied between 251 and 269 days with 40 to 60 year intervals. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 15/06/2026

Berkeley Earth global temperature to May 2026 + trend forward compared to 1850-1900. Current temperature: 1.41 (May 1.35) Rate of increase: 1970-2026: 0.21 deg/decade 1970-2010: 0.19 2010-2026: 0.36 2015-2026: 0.29 With current trend, 1.5 degrees will be reached in 2029, 2.0 in 2046.

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Thomas Karlsson @thomaskarlsson.bsky.social · 12/06/2026

WZ Del is another star among the SAAF's 50 forgotten miras. It was discovered in 1930 by Cuno Hoffmeister. Not much observational history exists for the star before SAAF began observing it in 2012. Its period, currently 259.1 days, is quite short and appears to be stable.

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Thomas Karlsson @thomaskarlsson.bsky.social · 03/06/2026

R Tri is a short-period and bright mira. It was discovered in 1890 by the English amateur astronomer THEC Espin and independently by Williamina Flemming at Harvard. The phase diagram shows 569 observations made by SAAF/V from 1990 onwards. From these observations the average period is 265.16 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 22/05/2026

From my database of maxima for mira variables. T Scl is on my list of miras with changing period. It is also an example of their unpredictability. 1890-2010 it had an increasing period. But after 120 years the pattern has changed and now the period is decr. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 14/05/2026

Berkeley Earth global temperature to April 2026 + current trend forward. Current temperature: 1.41 Rate of increase: 1970-2026: 0.21 deg/10 years 1970-2010: 0.19 2010-2026: 0.36 2015-2026: 0.30 With current trend, 1.5 degrees will be reached in 2030, 2.0 in 2047.

Red line: One year moving average. Blue Line: 21 year moving average + confidence interval and current trend forward.

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Thomas Karlsson @thomaskarlsson.bsky.social · 13/05/2026

WX Del is one of the SAAF's 50 Forgotten Miras. It was discovered by Cuno Hoffmeister in 1930. WX Del is the longest-period mira of the 50 on the SAAF's list. The current period is 528.8 days, close to the average period since 1897 of 528.3 days. The diagram shows SAAF observations 2012-2026.

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Thomas Karlsson @thomaskarlsson.bsky.social · 05/05/2026

R Boo is a bright and fairly short-period mira. Here is a phase diagram with observations made within SAAF/V 1990-2025. Most are visual (black) but also some photometric with V-filter (green). The star's period is quite stable with a variation between 222 and 226 days during the observed time.

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Thomas Karlsson @thomaskarlsson.bsky.social · 24/04/2026

From my database of maxima for mira variables. AF Car is on my list of meandering miras. Its period has since 1896 varied between 425 and 456 days. The star has not been observed much before the 1970s so much of its older history has been taken from #DASCH. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 17/04/2026

V2330 Cyg is a mira among the SAAF's 50 forgotten miras. Discovered by Mike Collins, UK, in 2000 and independently by Lennart Dahlmark, Sweden, in 2001. The average period since 1899 is 382.5 days. Its current period is similar, 383.6 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 07/04/2026

Alpha Ori or Betelgeuse, the orange-red supergiant in Orion that could go supernova any day in the next 100,000 years. In 2020, the star had a sharp dip in brightness. Below are SAAF's visual observations of Betelgeuse since 2018.

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Thomas Karlsson @thomaskarlsson.bsky.social · 26/03/2026

V2331 Cyg is an deep eclipsing binary that was misclassified as an irregular variable. In 2012, members of SAAF/V discovered its true nature. After a few months of observations, the correct period could be determined. We also wrote a short article in JAAVSO about the star.

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Thomas Karlsson @thomaskarlsson.bsky.social · 18/03/2026

From my database of maxima for mira variables. T UMi is a former mira that is now classified as semi-regular. Until 1970 it was a normal mira with a period of 315 days. Then its period quickly dropped to under 200 days before it stopped pulsating regularly. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 05/03/2026

Here is a graph showing Swedish solar observations since 2020. Gray crosses are individual observations, the blue line shows the mean value per month and the red line is a moving average over 12 months. Maximum solar activity was reached in October 2024.

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Thomas Karlsson @thomaskarlsson.bsky.social · 26/02/2026

V2072 Cyg is another mira among SAAF's 50 Forgotten Miras. The variable was discovered by the Swedish amateur astronomer Lennart Dahlmark in 1982 with the designation LD 55. The period has been fairly stable since 1895 with a mean value of 318.6 days. Since 2012 it is 316.8 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 13/02/2026

I have used data from Berkeley's new climate model with 0.25 deg resolution and made a new temperature forecast. The temp in this model is slightly lower than in their previous 1 deg model. The global temp now reaches +1.5 deg in 2028, +2 in 2044, if the temp increase continues at the same rate.

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Thomas Karlsson @thomaskarlsson.bsky.social · 11/02/2026

From my database of maxima for mira variables. T Peg is on my list of meandering miras. The star was discovered in 1863 by John Hind. According to my calculations, its period has varied between 360 and 386 days or 7.1%. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 03/02/2026

V742 Lyr is an R Coronae Borealis, or RCB, variable. A rather unusual type characterized by irregular, sudden and very deep drops from the star's normal brightness. V742 has been observed within SAAF since 2012 and is now recovering from its most recent decline.

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Thomas Karlsson @thomaskarlsson.bsky.social · 25/01/2026

V750 Cyg is one of the SAAF's 50 Forgotten Miras. Discovered 1938 by the Russian astronomer Pavel Parenago. The average period is 428.4, but the current period is more like 421 days. This makes the phase diagram quite fluffy and the maximum point shifted. It also has a hump on the ascending branch.

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Thomas Karlsson @thomaskarlsson.bsky.social · 14/01/2026

Berkeley has just released temperature data for 2025. From their data, my own calculation of the Earth's average temperature with a 21-year moving average and a forecast to 2050. +1.5 degrees is now predicted to occur in 2027, one year later than the forecast showed last year.

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Thomas Karlsson @thomaskarlsson.bsky.social · 12/01/2026

From my database of maxima for mira variables. Z Vir is on my list of stars with continuously changing periods. Since 1881 its period has decreased from 310 to 298 days or 4.1%. The star was discovered in 1880 by Johann Palisa. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 02/01/2026

For the 510 miras in my database there are now new mean light curves. These are constructed from all, 100+ years, observations. Many curves are similar to each other while others, like U CMi, deviate with its double maximum. The curves can be found via var.saaf.se/mirainfotot....

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Thomas Karlsson @thomaskarlsson.bsky.social · 30/12/2025

TT Aur is an eclipsing binary of subtype EB. The star was discovered in 1907 by Henrietta Leavitt at Harvard. The phase diagram shows my observations from 2009-2018 from images I took with my DSLR camera of epsilon Aurigae during its eclipse.

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Thomas Karlsson @thomaskarlsson.bsky.social · 21/12/2025

V673 Cyg is a mira among the SAAF's 50 Forgotten miras. It was discovered in 1943 by Cuno Hoffmeister at Sonneberg. Since SAAF began observing it in 2012, its period has been 327.0 days. Since 1890, the average period has been almost the same, 326.4 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 10/12/2025

From my database of maxima for mira variables. R Lep, or Hind's Crimson Star, is a carbon star that is on my list of meandering miras. The star has a deep red color, beautiful to watch but harder to observe. Since 1853 its period has varied 417-447 days. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 01/12/2025

V718 Tau is a red carbon-mira (B-V=4.5) observed within SAAF since 2011. In recent years it has become noticeably brighter by 1.5 magnitudes. Its period from SAAF data is 405 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 24/11/2025

On the evening of Nov 21, a big bolide passed over eastern Sweden. It was visible for a long time, more than 20 sec. According to Erik Stempels at Uppsala University, it was probably a very unusual earth-grazing meteoroid that only bounced off the Earth's atmosphere. www.youtube.com/watch?v=otnC...

youtube.com

Bolid över Västerås 22/11 2025

YouTube video by VARF Akesta

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Thomas Karlsson @thomaskarlsson.bsky.social · 19/11/2025

V663 Cyg is another mira among the SAAF's 50 forgotten miras. Discovered in 1949 by Cuno Hoffmeister at Sonneberg. The current period is 361.5, about the same as it has been historically. The fact that the period is close to a year means that observations are missing at the same phase in the diagram

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Thomas Karlsson @thomaskarlsson.bsky.social · 10/11/2025

From my database of maxima for mira variables. V Del is a long period mira that is on my list of miras with a decreasing period. Since 1890, its period has decreased by 22 days, although with great variation over time. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 30/10/2025

T Mon is a bright Cepheid with a fairly long period. Here is a phase diagram with my observations of the star from 2010 to 2023. The light curve has a rapidly rising phase over 7 days and a slow decline over 20 days. Its period has a small continuous increase of about 13 seconds/year.

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Thomas Karlsson @thomaskarlsson.bsky.social · 24/10/2025

V462 Cyg is a mira star among the SAAF's 50 Forgotten Miras. It also has a meandering behavior where the period has varied between 362 and 381 days. This is visible through the large spread in the phase diagram.

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Thomas Karlsson @thomaskarlsson.bsky.social · 17/10/2025

SX Aur is an eclipsing binary of type EB that I observed from 2008 to 2018. The star is a bycatch in the images I took with my DSLR camera when I followed the eclipse of epsilon Aurigae. The phase diagram contains 379 observations.

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Thomas Karlsson @thomaskarlsson.bsky.social · 10/10/2025

From my database of maxima for mira variables. RU Sco is on my list of meandering mira stars. Since 1889, the period has varied between 351 and 377 days. The star was discovered in 1895 at Harvard by Williamina Fleming. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 03/10/2025

V363 Cyg is a mira among the SAAF's 50 Forgotten Miras. The star was discovered in 1928 by Frank E. Ross at Yerkes Observatory. The phase diagram shows observations made by SAAF members 2012-2025. From DASCH data, the average period since 1899 is 358.9 days. Since 2012, the period is 360.5 days.

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Thomas Karlsson @thomaskarlsson.bsky.social · 23/09/2025

KUV 18217+6419 is a variable quasar, 3 billion light-years away, in the constellation Draco that I have been following photometrically since 2016. In the past year it has been unusually bright and close to its maximum stated brightness.

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Thomas Karlsson @thomaskarlsson.bsky.social · 12/09/2025

‪‪From my database of maxima for mira variables. SU Vir is on my list of miras with continuously changing periods. SU Vir has a behavior similar to the previously presented stars WX Her and DO Her. Since 1897, its period has decreased from 213 to 206 days. More miras at var.saaf.se/mirainfooc.php

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Thomas Karlsson @thomaskarlsson.bsky.social · 03/09/2025

GS Cyg is one of the longer-period miras among the SAAF's 50 Forgotten Mira Stars. The star was discovered in 1927 by Frank E. Ross at Yerkes Observatory. Since 1891 the average period has been 413.6 days. The current period is 412.9 days. The phase diagram shows 284 observations 2012-2025.

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