Pushy Orion Nudges Out The Northern Cross On November Nights

In this nearly 360-degree view, the sky is shown at 10 o’clock local time when Orion and the Northern Cross (also known as Cygnus the Swan) are opposite one another. SE stands for the  southeast direction and NW for northwest. Created with Stellarium

Orion the Hunter rises, the Summer Triangle sets. These two opposing groups of stars lie on opposite sides of the sky from one another and represent the great seasonal divide of summer and winter. Nowhere is this more obvious than in the stance of the Northern Cross.

The Northern Cross led by its brightest star Deneb stands above the western horizon Friday night. Photo: Bob King

I noticed it Friday night while out walking the dog. Cygnus the Swan a.k.a. the Northern Cross stood exactly upright in the northwestern sky around 10 o’clock. Meanwhile Vega, the brightest star in the Summer Triangle, required some neck twisting to see, hidden as it was by tree branches to the lower right of the Cross. In the exact opposite corner of the sky Orion and his tri-star Belt led a charge of bright winter stars laying waste to the dim constellations of the fall southern sky.

Brilliant Jupiter (top) and Orion (left), with his three-stars-in-a-row belt, shine through the clouds in the eastern sky Friday night. Photo: Bob King

Despite their seasonal differences, the “alpha” or brightest stars of Cygnus and Orion – Deneb and Betelgeuse – are both supergiants with diameters so large they make the sun look point-like in comparison. Before continuing, you must know that Betelgeuse, is not Orion’s brightest star despite its designation as Alpha Orionis. It’s bested by a few tenths of a magnitude by Rigel in the hunter’s foot. Since Betelgeuse is a pulsating variable star with a diameter and brightness that changes over the months and years, it may at times wax brighter than Rigel.

Astronomers estimate Betelgeuse varies between about 550 and 920 times the size of the sun as it expands and contracts, unable to reach stasis like our more dependable star. These ups and downs are all part of Betelgeuse’s evolution from a red supergiant to potential supernovadom – one winter evening we may look up to find it’s blown its top, outshining every star in the nighttime sky.

Deneb is an enormous blue-white supergiant star some 100-200 times the size of the sun. It appears as a modestly bright 1st magnitude star because it’s over 1,500 light years away. Betelgeuse in comparison is only 642 light years away. Illustration: Bob King

Betelgeuse’s counterpart Deneb in the Northern Cross is likewise a supergiant but a younger, much hotter blue-white star 100-200 times the sun’s diameter. Both these great giants and their respective constellations draw our eye this time of year, when the leaves are down and the stars sparkle between tree branches like stellar tinsel.

11 Responses

  1. Tim Fleming

    I would hate to ruin such a beautiful constellation as Orion – but I would like to see Betelgeuse go supernova one night. I wonder if it has already?

    1. astrobob

      I share your sentiment but would gladly take the trade-off. Now maybe I’d feel differently if we lost one of the belt stars.

  2. havealual

    What is the dim light in the sky just to the right roght of orions top right star its been there a for a few weeks now there’s a super bright star that comes up in the east a little bit after it gets dark before orion comes up and if I look up and to the right of that super bright star I can see a cloudy light I don’t have a telescope but I can see it just wonderining I see it tonight also. Right now its 0130 and its up and to the right of the far right star of orions belt. Please forgive my lack of names as I do not know them any help would be appreciated

  3. havealual

    So the super bright. One is jupiter. So what about the dimmmer light I will try to show u about wher it is.



    I know I am probably missing some thing in orion but at about 120 to 130 the ? Maarks the spot of interest and about an hour after jupiter is nice and awake in the east the ? Can be seen up from and to the south of jupiter sorry for the child like pic;-)

    1. astrobob

      Just to the right of Jupiter is a V-shaped star cluster called the Hyades with one bright reddish-orange star named Aldebaran. Farther to the right and above the Hyades is a dense bunch of stars called the Pleiades or Seven Sisters cluster.

  4. William John Meegan

    I really appreciate your JPEG on PUSHY ORION NUDGING OUT THE NORTHERN CROSS. I was looking for a way to illustrate that these two constellations together inspired the building of the Giza Plateau. That is taking both Robert Bauval’s and Andrew Collins theories and merging them into one. In fact I am writing up a blog at the present moment in which I will air this theory; however, it is about another subject matter altogether: WHAT CAUSES AND BRINGS ABOUT LIFE ON EARTH? I am an esoterist and my research is wholly hone in that direction..

  5. jackie

    Wow, does it look cool on this page? I learnt what the real life northern cross! I am so happy now!!!!!!!!!!! Anyway i am still a child. At my school, the CSIRO person came and talked about the universe.

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