Posted on 09/19/2020 3:49:27 PM PDT by MtnClimber
Explanation: Orion is a familiar constellation. The apparent positions of its stars in two dimensions create a well-known pattern on the bowl of planet Earth's night sky. Orion may not look quite so familiar in this 3D view though. The illustration reconstructs the relative positions of Orion's bright stars, including data from the Hipparcus catalog of parallax distances. The most distant star shown is Alnilam. The middle one in the projected line of three that make up Orion's belt when viewed from planet Earth, Alnilam is nearly 2,000 light-years away, almost 3 times as far as fellow belt stars Alnitak and Mintaka. Though Rigel and Betelgeuse apparently shine brighter in planet Earth's sky, that makes more distant Alnilam intrinsically (in absolute magnitude) the brightest of the familiar stars in Orion. In the Hipparcus catalog, errors in measured parallaxes for Orion's stars can translate in to distance errors of a 100 light-years or so.
For more detail go to the link and click on the image for a high definition image. You can then zoom by moving the magnifying glass over an area and then clicking. The side bars will move the zoomed area over the photograph.
Pinging the APOD List
It has been a long time since I read about magnitudes, but I recall that a difference of 5 magnitudes means 100 times difference in brightness, so Alnilam is about 100 times as bright as Bellatrix.
Betelgeuse (the upper left star) dimmed greatly last year and early this year. It is a variable star so it does that sometimes though not to this extent. I have been trying to find it's current magnitude.
All of this just takes your breath away. What an amazing universe we have.
And this topic is a welcome, double-plus-good diversion from the unrelenting negativity of stuff occuring on Terra Firma.
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I tried explaining this to a stoner UFO freak that said most UFO’s come “from Orion.” I think he thought of it in two dimensions.
Tell him to cut down on the bong hits.
Haven’t seen him for a while. He had dreams that he believed were from God, and was writing a book about them. I had to listen to a bunch of his UFO stories. Oddly, they mostly seemed to happen near AF bases in California, and sounded like afterburner sightings. When they blinked out, he attributed it to the vessel cloaking itself. OK.
Betelgeuse, Betelgeuse, Betelgeuse!......................
Some crisp clear cold winter nights you can almost see Betelgeuse get dimmer and brighter.....................
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