Can we tell when a Star has died the moment it happens?

  • Context: High School 
  • Thread starter Thread starter GKDAIR
  • Start date Start date
  • Tags Tags
    Moment Star
Click For Summary

Discussion Overview

The discussion centers around the concept of observing the death of stars, particularly whether we can know immediately when a star has died or if there is a delay due to the time it takes for light to travel from the star to Earth. The scope includes theoretical implications of light travel time and observational astronomy.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that when observing distant stars, such as those in the Andromeda Galaxy, we are seeing light that was emitted millions of years ago, meaning we are looking into the past.
  • It is suggested that if a star like Andromeda were to die today, we would not know until the light from that event reaches us, which could take millions of years.
  • Participants note that even for our own Sun, there is an 8-minute delay in perceiving changes, as the light takes that long to reach Earth.
  • One participant clarifies that the process of a star becoming a red giant is gradual and takes thousands to millions of years, rather than being an instantaneous event.
  • Anecdotal reference to a SciFi story highlights the difference in visibility of events at different distances, suggesting that effects closer to us are observed immediately, unlike distant stars.

Areas of Agreement / Disagreement

Participants generally agree on the concept that there is a delay in observing the death of stars due to light travel time. However, there are nuances in understanding the processes involved, particularly regarding the gradual nature of stellar evolution and the implications of such delays.

Contextual Notes

Participants express assumptions about the nature of light travel and the time it takes for changes in stars to be observed, but do not delve into the mathematical details or specific definitions of terms used.

GKDAIR
Messages
7
Reaction score
0
Light just now reaching us from Andromeda Galaxy was created literally millions of years ago, around 2.5 to be in the ballpark.

When you look at a star, you're literally looking at the past.

That means tonight, when we look up, The light that let's us see Andromeda was created when the genus Homo first appeared here on Earth.


Is it possible that Andromenda, or any other star for that matter, could be dead and gone, but we don't know about it because the light hasn't traveled far enough yet?

Like for example, if Andromeda just suddenly died today, would we know about it? Or would we not find out until 2.5 million years from now and suddenly realize we can't see it anymore

Hopefully I'm phrasing my question correctly.
 
Astronomy news on Phys.org
Yes we only see the light that was emitted 2.5 million years ago, if andromeda or anyother star went supernova today we won't know until enough time has past for that light to reach us. The time in years is the same as the number of light years away the object is. Even for our own Sun the light is 8 minutes old by the time we see it here on earth.
 
Trollcast basically summed it up. Even when our Sun becomes a red giant, we will not be able to tell until about 8 minutes after the actual event. But at the point we find it out. We will all be killed so it really won't matter.
 
Ah, that's what I figured. Thanks for clearing that up.
 
ConnorL0404 said:
Trollcast basically summed it up. Even when our Sun becomes a red giant, we will not be able to tell until about 8 minutes after the actual event. But at the point we find it out. We will all be killed so it really won't matter.

Well... to be clear, becoming a red giant is a continual process that takes thousands to millions of years once it's started, not an event that just suddenly happens.

But yes, it takes 8 minutes for any changes in the sun to reach us.
 
I remember reading a very short SciFi story about a mage who told his emperor he discovered how to make a star disappear. Emperor pointed to some star and asked the mage to do his trick. And the mage did, but the star was still twinkling...

If memory serves me well story didn't end up good for the mage. Emperor had some disappearing tricks ready too, and because of the much smaller distance their effects were visible instantly.
 

Similar threads

High School Why does the Andromeda galaxy appear so tiny from our perspective?
  • · Replies 81 ·
3
Replies
81
Views
16K
High School Can the "Dark Energy" concept be wrong?
  • · Replies 13 ·
Replies
13
Views
3K
High School Distance of Stars / Size of the Universe calculation
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad How Can We Measure Properties of Distant Planets and Stars?
  • · Replies 12 ·
Replies
12
Views
3K
High School Question About The Stars -- Can they have died before we see their light?
  • · Replies 5 ·
Replies
5
Views
2K
High School How do we know the stars are not our own light falling back.
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad What do high-mass X-ray binaries, or HMXBs, tell us?
  • · Replies 1 ·
Replies
1
Views
2K
High School What Would We See When Traveling to a Star at Light Speed?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Where can I find publicly accessible data from observatories in Europe?
  • · Replies 5 ·
Replies
5
Views
2K
High School Transferring information faster than the speed of light
  • · Replies 24 ·
Replies
24
Views
3K