Betelguese fades a full magnitude

Chronological Encyclopedia of Discoveries in Space cover

After being in print for twenty years, the Chronological Encyclopedia of Discoveries in Space, covering everything that was learned on every single space mission in the 20th century, has finally gone out of print.

I presently have my last four hardback copies available for sale. The book sold new for about $90. To get your own autographed copy of this now rare collector's item, please send a $120 check (which includes shipping) payable to Robert Zimmerman to

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"The Chronological Encylopedia of Discoveries in Space is no passionless compendium of information. Robert Zimmerman's fact-filled reports, which cover virtually every spacecraft or probe to have ventured into the heavens, relate the scientific and technical adventure of space exploration enthusiastically and with authority." -- American Scientist

Long term observations of the red giant star Betelguese have found it to have faded a full magnitude in the past few months, dropping it from 6th brightest in the sky to the 21st.

You will see a lot of bad journalism related to this story, hyping the fact that Betelguese is considered one of the top nearby stars to someday in the far future go supernovae. However, the recent change in brightness is unlikely related to this and is nothing unusual, as the star fluctuates regularly.

The current faintness of Betelgeuse appears to arise from the coincidence of the star being near the minimum light of the ~5.9-yr light-cycle as well as near, the deeper than usual, minimum of the ~425-d period.

The star is definitely interesting, because it is so large (if placed in our solar system its surface would be around the orbit of Jupiter) and so defuse, more like a partly filled gasbag. However, the odds of it going supernovae in the near future is quite unlikely.



  • Phill O

    Thanks for the critique!

  • David

    Clearly, the dimming was actually caused by the smoke from the attack ships on fire off the shoulder of Orion. This is 2019 after all!

  • David – nice!

    I thought the ‘bad journalism’ might be stories that Betelguese is an ‘indicator star’, and a warning that humans are harming the galaxy.

  • Ken

    David, very nice!

    Blair Ivey, it’s likely related to retreating glaciers /sarc

  • wayne

    excellent cultural reference!

    Rutger Hauer
    Bladerunner (original)
    {-Incept date 1/23/44. 75 year life span.}
    “I’ve seen things…..”

  • M

    The stars are going out.

  • Milt

    “Overhead, without any fuss, the stars were going out.”

    Arthur C. Clarke, The Nine Billion Names of God, 1953

    One factual question: As Betelguese dims, is it also getting redder? This would not be atypical, but I have not seen any
    discussion of this.

  • wayne

    “What Will It Look Like When Betelgeuse Goes Supernova?”
    V101 Science 2018

  • Col Beausabre

    I first read the “Nine Billion Names of God” as a teenager and it knocked my socks off as I discovered that Science Fiction was more than Space Opera. Further in the paperback was “The Star” – which I consider the most horrifying Christmas Story of all time. The combination caused JBS Haldane to tell him that if he had been more consistent in his religious views as expressed in his stories, he would have been a serious public menace.

    Both stories are available on line

  • Col Beausabre

    “him” is Arthur C Clarke

  • Diane Wilson

    Also quoting Blade Runner,
    “If only you could see what I’ve seen with your eyes.”

  • wayne

    F16 Guy–
    Yow, Hilarious! I about spewed my coffee all over the keyboard.

    Good stuff!

    “I’ve done…questionable things.”
    (nothing the God of bio-mechanics wouldn’t let you into heaven for)

  • Lee S

    The constellation of Orion is my favourite, and spectacular here in the winter, in a reasonable dark area the nebula is clearly visible with the naked eye.
    Unfortunately so far this winter the sky has been overcast every time I have been outside in the evening, but when we finally get a clear sky it will be interesting to see if the dimming is noticeable… I actually hope so.. of course we see the planets change position, and the phases of the moon etc… But to see with the naked eye another star change would be kinda cool.
    ( And if course we should all keep fingers crossed it does go Nova… Then I could show my daughter what she is named after…)

  • Paul Sventek


    Learn to find the star Algol (Beta Persei) in the constellation of Perseus. It is an eclipsing binary star with an orbital period of 2.86 days. It’s not hard to find predictions for the middle of the eclipse when the star is a little more than 2.5 times fainter than when it isn’t in eclipse. There’s a star near it which is about the same brightness as when Algol is in maximum eclipse so it’s easy to tell when Algol is normal brightness or not. The difference is quite striking even to the naked eye. It’s been called the Demon Star for thousands of years.

  • Lee S

    @ Paul Sventek, thank you my friend!!! I’m mostly into planetary viewing.. I only have a hodgepodge 4″ refractor built from a Soviet era extremely huge telescopic photo lens, an interesting combination of prisms and some old microscope lenses… But it works…
    Now I have something extra solar to get excited about, and a project for the kids to at the very least get kudos in science about!!
    A very good year to you my friend… And thank you once more!!!

  • pzatchok

    Its another one of those extra-terrestrial constructs that blocks out some of the light coming from a few stars.

    They are building fleets. Fleets the size of solar systems.

    Or someone forgot to pay the power bill.

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