Today Sirius, the brightest star in the night sky is an unmistakable blue-white in colour although it does twinkle a lot and can appear to change colour. However no one would think of describing it as red.It is thus a source of confusion that many ancient writers describe the star as red or  ruddy. Assuming that colour blindness wasn’t rampant in the distant past this discrepancy is a puzzle that has exercised the minds of modern astronomers and other interested parties, including myself in recent weeks.

I have come to the conclusion that Sirius was never red, based on

(a) what I consider to be unreliable use of the ancient sources,

(b) the evidence from Chinese records that unfailingly refer to the star as white and

(c) the fact that if we accept that Sirius was red roughly 2000 years ago then we have to seriously question modern accepted thinking on the life cycle of star

Image of Ptolemaeus

Claudius Ptolemy probably didn't look much like this depiction from 1400 years after his death (image credit: via


One of the most oft quoted sources of this alleged red colour of Sirius is the ancient Greek astronomer Claudius Ptolemy (A.D. 90 to 168). Around 150 AD, in his famous Almagest, he described Sirius as reddish, along with five other stars, Betelgeuse, Antares, Aldebaran, Arcturus, and Pollux, all of which are clearly of orange or reddish hue. So he was 60 years old and could have had cataracts or been colour blind!  Or, as we only have copies of what Ptolemy wrote there is room for error in copying. A sleepy and overworked scribe might easily have made a slip of the quill (pen) which then got carried into all future copies.  Also apparently there is a version of Ptolemy that does not include Sirius in that list of red stars. Maybe a scribe added it in as a joke; an April Fool’s joke that has lasted almost 2000 years!! But the problem is, according to much of the literature on this subject, Ptolemy (and I will return to him later) was not on his own; many other ancient writers also described Sirius as red, some even writing prior to Ptolemy.

The Greek poet Aratos (3rd century BC) is often listed in support of the ancient red hue of Sirius.  In his poem Phaenomena (326-34), Aratos uses the term poikilos when describing Sirius. This word can be translated as ‘many coloured’.  Where is red coming from? In translating the said poem into Latin Cicero (106-43 BC), the famous Roman orator used the words’ rutilo cum lumine claret fervidus ille Canis’,  which translate to English as ‘with ruddy light fervidly glows that dog’. We must remember that neither Aratos or Cicero were astronomers and true meaning can be lost in translation especially when poetry is the subject matter.

Pliny the Elder (23-79 AD) writing in his monumental work Natural History highlights many astronomical facts. He is often quoted as describing Sirius as reddish. He cites three heavenly bodies as ardens or igneus: the rising Sun, Mars, and Sirius. (Nat. Hist. II 18 47.)  A quick look at a translation (etymology) of these words reveals several meanings including burning, shinning, brilliant and fiery. I do not see that we can rely on this source for the actual colour of Sirius. Pliny could have been referring to the undisputed brightness and brilliance of Sirius.

The narural philosopher Columella (4-70 AD) is invoked as support for the ‘red’ Sirius theory.  Writing about roses he likens their hue to Tyrian purple, the rising Sun, Sirius, and Mars. (De Cultu Hortorum X 286.) He could well be referring to different varities of  roses. And there are all manner of colour of roses. I am not convinced that Columella really intended to tell us anything about the colour of the Dog Star.

Image of Sirius_A_and_B

An artist's impression showing how the binary star system of Sirius A and its diminutive white dwarf companion, Sirius B, might appear to interstellar travellers. (Image credit: NASA, ESA, G. Bacon (STScI) )


Returning to Ptolemy, his evidence is the big hurtle to overcome in this debate.He is of course a formidable ally quoted by many in support of the ancient red colour of Sirius.If Ptolemy said it was red then it must have been so.It would be difficult to argue with an intellect as great as Ptolemy’s.I do not argue with Ptolemy but I do take issue with how he is invoked/used to lend credence to the red theory.

In a very interesting article Lynn, W. T. (1887) suggests that Sirius was never red; the whole notion was founded on a mistake. He calls attention to Professior Schjellerup’s detailed translation of Al Sûfi’s account of the heavens in which the famous Arab astronomer used Ptolemy’s Almagest , but doesn’t render Sirius ‘red’.  There is reference here also to the idea that Ptolemy only named five stars as being red, the addition of Sirius to the list being based on a transcription error. I am convinced by the argument and information in this article that the origin of ‘red’ Sirius hypothesis is indeed a red herring. This article is well worth a read; don’t be put off by the French, it is not essential to the basic argument. With Ptolemy discredited as a reliable source for the ‘red’ colour of Sirius I think we should but this debate to bed.

But let’s not be too hasty, there is further support for a white Sirius in Chinese records. Jiang Xiao-yuan of Shanghai Observatory gives an excellent overview and argument on the Chinese perspective.

The Heavenly Wolf as it was known to the Chinese was actually used as a benchmark for the colour white.It is consistently referred to as being white by ancient Chinese writers.No records claim any redness whatsoever. Jiang Xiao-yuan concludes that Ptolemy was simply wrong (… it may be noted that SIMA Qian predated Ptolemy by some two hundred years and since Sima Qian took Sirius as standard for white star, it is quite impossible for the star to have changed into red in the interim. It is therefore obvious that Ptolemy’s statement that Sirius is red cannot be given credence.)  whereas I think that it is more likely that there has been a mistake which has been perpetuated. In other words though I agree with his conclusion, I favour the explaination put forward in W.T. Lynn’s article.

Ancient Chinese sources stating unequivocally that Sirius was all the time white  combined with the toppling of Ptolemy as a proponent of ‘red Sirius’ by Prof Schjellerup really weakens the ‘red’  Sirius theory. It is further undermined by the fact that it is  inconsistent with current  stellar evolutionary theory.


image of sirius by HST

This Hubble Space Telescope image shows Sirius A along with its faint, tiny stellar companion, Sirius B. The cross-shaped diffraction spikes and concentric rings around Sirius A, and the small ring around Sirius B, are artifacts produced within the telescope's imaging system. ( Image credit: NASA, ESA,H. Bond (STScI) and M. Barstow (University of Leicester))


Let’s consider if Sirius maybe was red in colour 2000 odd years ago. What we see as the brightest star in the night sky is actually a binary star comprising Sirius A, a main sequence star and Sirius B, a white dwarf. The red giant phase of a star, when a star does actually appear red, is a prerequisite to becoming a white dwarf.The possibility that Sirius B could be responsible for ‘red Sirius’ has been rejected by astronomers on the grounds that the timescale of thousands of years is too short and there is no sign of the expected nebulae. A more detailed account of Sirius can be found here . While we always have to keep an open mind I think that the current theory of stellar evolution is safe.

(Aerticle by Mary Bulman, Education Support Officer)


Francis Saturn Mendiola · March 31, 2019 at 17:46

Seriously? Accusing the great Ptolemy of Cataract? What do you mean? When Ptolemy write the Almagest he just look up and saw the red Sirius? As astronomer they observing the stars their whole life and saw Sirius in RED! This is the proof that star cycle is wrong, so be it. Let us find another theory and that is science do.

pokerclub88 · December 18, 2018 at 04:12

This site is one of the best I have found.

poker terbaik · December 5, 2018 at 08:35


Steve · December 29, 2016 at 20:51

In early October 2016 Sirius appeared much larger than normal (approximately one third the size of a full moon). It was bright orange / dull red and flickering. Initially I thought something was ablaze in the village but it remained circular and I realised atmospheric conditions were making Sirius appear much larger than normal. This was at 3:10 am and when I looked 10 minutes later it couldn’t be seen at all. The next morning I looked again at 3 am and it was there in exactly the same position but much smaller, and flickering with the same orange light. I had set up a camcorder hoping it would appear at a similar size but in the event it was hardly worth recording. Location : South Yorkshire, with Sirius low on the horizon.

Carol Schrum · November 14, 2016 at 06:33

I saw Sirius sparkling magenta red, white and blue little over an hour this evening, an hour after rising. Clear cool night, never saw it that colorful before. That is what landed me here now. The red is fading but is still sparking, less intensely.

Daniel Sobers · March 30, 2015 at 05:26

I’m convinced based on much research and consideration, that Sirius the great Egyptian or should I say the human race’s mother Goddess of our Earth and Solar System, is the centre point or orbital central mass for our Sun. Our Sun or Son (Christos Helios/Anointed Sun/Jesus Christ), is the Binary Star to Sirius and when viewed in the past was seen moving away from us and our Sun, but since the end of the Mayan cycle and the Sun’s journey up through the Galactic plain out of the dark ages, towards the Golden age of enlightenment, we now seen Sirius as white or Blue as it is moving towards us as we head towards it. This sheds more light (enlightenment) on all human beings (increased magnetism and consciousness). The orbital cycle will take between 24-26,000 years as does the precession or wobble of our planet Earth. So basically Sirius was moving away from the earth causing a red field and is now moving towards earth creating a blue/white field. Sirius, Isis or Mother Merry is our Sun’s, Sol’s (Christ’s) binary star. 🙂

    admin · March 30, 2015 at 08:48

    Dear Daniel, thank you for your comment but I must point out that the Sun and Sirius are completely unrelated; they do not make up a binary system.

      Lee Hogan · May 2, 2016 at 20:38

      hi admin, can you prove that then? Id like to know. I was going to try work it out in redshift.
      you could save me some time. thanks.

        admin · May 3, 2016 at 08:59

        Dear Lee, thank you for your question, but I am not sure what you are asking. Are you asking me to prove that the Sun is not part of a binary system?

          lee hogan · June 13, 2018 at 15:21

          Yes.. how can we prove our sun is not in a binary system with sirius or another star? If we are in a 24-26000 year cycle it would be so slight over time surely. Lot of things point to us being in a binary system.

    Lee Hogan · May 2, 2016 at 20:36

    ive been researching this lately Daniel. I, at moment, have the same view. Ive just come to same conclusion then ive arrived here and read your comment. and the one below. hmm

    John · September 20, 2016 at 12:35

    Good one david me too I am convinced

xenubarb · January 21, 2015 at 12:20

I don’t indulge in astronomy, because I have really poor night vision. Plus, I live in a city in southern California, where light pollution is severe.

So imagine my surprise to notice a star the other night, brighter than all the others, twinkling ferociously, and flashing blue and red. Seriously, I thought it was a police helicopter hovering over Mission Bay. Only it was there the next night. And the next night. I concluded it was not a helicopter, and posted to Facebook about it.

There, I was told the red and blue flashing star was Sirius. It may not have ever been red, but it certainly has flashes of it. I seen ’em!

So last night I was going to get my little telescope out and look at it. Wouldn’t you know, it’s been overcast for the past two nights. I really want to get a better look at this thing.

D Lumb · December 8, 2014 at 20:56

Isn’t this just the same as the well-know controversy about the “wine dark sea” of Homer. It is not that the Greeks really thought the sea to be red – just they didn’t have blue in the vocabulary. (Then you get into lingo-psychological studies about whether inability to express a concept actually modifies you perception !) So maybe Ptolomey and the other greeks knew Sirius to be blue-white and had not the vocabulary to say so !!

Blodwyn Flowers · January 24, 2014 at 00:03

I have filmed the sirius star flashing red, its lovely, seems like its an atmospheric effect.

    admin · January 24, 2014 at 10:02

    Hi, any possibility you could share this with us?

Blodwyn Flowers · December 23, 2013 at 23:18

Hello, I live in west wales uk and have always enjoyed the winter sky’s and a favorite of mine has been Sirius, I have observed sirius for years with a reasonable pair of binoculars, and have introduced the colourful wonder to many friends,
I tell them that the star shines Red White and Blue, we look and true as the star exists, it flashes Red White and Blue, it always has done.

Who Cant See The Red ?

    EUnderhill · April 28, 2014 at 01:49

    The color changes you observe is due to your high latitude location and Sirius would be low on the horizon in your location. I live in the Phoenix Metro Area which is located at the 33 degree parallel and Sirius does pulsate red, white and blue when it is located low on the horizon shortly after rising. When it gets high enough in the sky away from the horizon, it only twinkles white.

      Stephen · January 26, 2016 at 02:06

      Yes, I am from Canada and often called it the “Pepsi” star because it would flash red and blue when it was low on the horizon.

    Justin · November 11, 2016 at 19:20

    Are you sirius?

DrP · February 15, 2013 at 17:42

“(c) the fact that if we accept that Sirius was red roughly 2000 years ago then we have to seriously question modern accepted thinking on the life cycle of star”

Of course that would impossible!!! Then you might become an other Galilea, right?!
Don’t you understand you’re not really objectif, thinking you’re smarter then all these historian writers ?…. Let’s see if you will be still well known after 2000 years!

Mark Gustafson · June 21, 2012 at 20:21

Ancient color is very interesting, but more interesting are the NASA “photos” – not just these of Sirius but all recent NASA photos. Start by inverting and zooming, dispel what your mind assumes it will see, and really look at the images. Do the same for all current images everywhere. Familiarize yourselves with ancient symbols as those disseminating images certainly are familiar – it would not surprise me if they have familiars.

    admin · July 16, 2012 at 10:51

    Do make sure you are looking at the originals and not compressed web versions!

Paul · June 3, 2012 at 21:57

there are some observations of red flares near Sirius even in recent history

The Life of John Louis Emil Dreyer | Astronotes · March 10, 2016 at 16:34

[…] by Professor Schjellerup  (who in my opinion put to bed a long time ago the argument about ‘red’ Sirius […]

Leave a Reply

Avatar placeholder

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.