Has there been any change in the formation of Orion since measurements could be taken and recorded correctly?

Question

Has there been any pulling away of the stars making Orion larger? Or is this not possible because of the influence the stars have on each other.

Answer 1

There has actually been some change. The brightest star in a constellation is called "alpha". The second brightest is called "beta" etc. In the case of Orion the star called Alpha Orionis, aka Betelgeuse, is not the brightest star in Orion anymore! Beta Orionis A, or Rigel, is. So since Orion was properly mapped and the brightness of its stars were measured one of those stars has either lost luminosity or gained luminosity. The culprit is probably Betelgeuse which is a highly evolved star near its death. A star that big and old would vary in brightness as it readies for its final show: the supernova. When Betelgeuse explodes (could happen any day) it will certainly become the brightest star in Orion one last time as it will be fully visible in daytime for weeks.

Answer 2

Ever notice how big and bright the moon appears when it's just above the horizon. This may be the affect you are noticing, or some similar phenomenon, making things appear bigger. Now imagine yourself at the center of an enormous balloon. Sketch the stars of Orion on the surface of the balloon with a magic marker. Continue inflating the balloon until it becomes twice as large. Does Orion now appear larger to the observer? No, the only difference is now the stars appear dimmer because they're farther away. That said, it is true that the nebulae are drifting apart as witnessed by their spectrographs. Also, all the stars are moving and there's no reason to expect all the stars in Orion to be moving in the same direction. So constellations will become distorted from their original configuration over time.

Answer 3

The answer is yes, they have moved. All stars move to some extent relative to Earth, and each other. However, the movement is so tiny from our viewpoint that over a lifetime we will not see a change. But, over thousand of years many stars will move appreciably. But, from a human lifetime perspective, and indeed since measurements were first taken, there has been some movement but it is so tiny we won't see the difference. Some stars appear to be moving faster than others, usually the fastest movers are closest to us.

Stars, especially in clusters or otherwise in close proximity to each other will influence each other to some extent. In some cases this can cause mergers or stars, in other cases the ejection of a star from a group or cluster. But, from memory, most movement of widely spaced stars is down to the whole lot being part of the galaxy and it merrily spins every 200-odd million years.

Answer 4

The formation that we call orion are not a 2 dimensional dots on a background, they are 3 dimensional and, even though 2 stars may look very close they may be millions of light years apart.

for example we may look at three stars * * * and think they are equally distant. however, if you were to look from a planet which is at 90 degrees you may see something like this
*.. ...... ........... ..... ........ *... ....*

the stars do not have any significant influence or gravitaional pull on each other.

Answer 5

There certainly hasn't been any significant change in recent years but from a retrospective point of view, modern instruments can show how Orion looked in the past and consequently can extrapolate this data to accurately predict how Orion will appear at any time in the future.

This, of course, assumes no unforeseen catastrophe!

Answer 6

Some constellations will look very different in the future but mainly due to the angle we are viewing them at rather than the relative distance of the component stars. The "square" part of the Plough or Big Dipper in 10,000 years time will look distinctly trapezoidal rather than it's almost square appearance now.

Answer 7

Yes they lost their lead singer!