Why certain stars seem to move very little in the sky

[Ittiandro]

OK, that's certainly one of the three stars that forms the summer triangle.

It will not the be same one(s) seen in the winter. In winter the summer triangle is low in the North West, if not below the horizon.
View attachment 265505

Yes, but I have been seeing this object in winter, too, at least for the past two winters. Usually winter skies are a lot more clear and this object is very bright.
I haven't looked at it lately, especially now because the skies are too hazy due to the heat, even though I live relatively outside the city. wave. .
I will try to get a more precise azimuth position of it with the compass as soon as the skies clear up.

Ittiandro

 

[DaveC426913]

Yes, but I have been seeing this object in winter, too, at least for the past two winters.

Alas. 'tis not the same object.

Anything you see high in the South East sky in the summer will be low in the North West sky come winter.

 

[Ittiandro]

FYI, threads like this can be extremely frustrating for the other members because the question should be easy to answer, but isn't due to poor information from you, the OP. You should be able to identify a bright object in the sky yourself, using an app on your computer or smartphone. Alternately, if you gave us an accurate time and rough location in the sky, we could easily identify it for you. But unfortunately your posts have been very difficult to understand.

Please keep it in mind that our ability to help depends strongly on the quality/clarity of information you can provide.

I thank you for your remarks

I do agree with you that the information I provided about that object was insufficient for the FYI to answer easily, if at all and I will soon try to provide more information, following the suggestions I am getting from other members.

If this is what you mean by saying that my posts are difficult to understand, I agree with you. .

Beyond that, I think that a part of your difficulty to understand ( and answer to) my posts may be that some have read too much ( or too little) in what I said when I started the thread.

I do believe that mathematics are, for those who know them, the clearest and the most unambiguous language to be used in science, but I am writing in modern English, neither in or about philosophy, or poetry, or Middle English, just plain, educated ( I hope) modern English.

If this comment of mine, like many others in the same vein, is still so difficult to understand, then I must give up, but it baffles me……

People like me, who, however well educated they may be, are not scientifically trained, can and will make incorrect statements, but it serves no purpose to engage in a display of scientific savvy by dissecting every single word or statement, at the cost of losing perhaps sight of the question and the overall drift of my original post, which was :

why does an obiect in the sky appear to move around very little across the seasons, in spite of the millions of miles traveled by the Earth along its orbit? .. Was this really so difficult to understand?

There were four possible ( but not necessarily right) answers to this question. Some of them have been advanced by other members..:

• An object cannot be visible in the sky year round, so I must be looking at two different objects..
• I am not looking at a star, but at a planet with a very long orbital time, which will make it appear moving very little relative to observers at any point of the Earth’s orbit.
• A star cannot appear to be moving because stars are fixed
• Other explanations of which I may not be aware, confirming that what I see is astronomically plausible and factually correct.

In fact some did understand better than others the drift of my post and offered plausible, if not convincing explanations…Ittiandro

 

[Ittiandro]

Alas. 'tis not the same object.

Anything you see high in the South East sky in the summer will be low in the North West sky come winter.

Alas, you convinced me. I'll still try to identify it as soon as the skies clear up

 

[Drakkith]

People like me, who, however well educated they may be, are not scientifically trained, can and will make incorrect statements, but it serves no purpose to engage in a display of scientific savvy by dissecting every single word or statement, at the cost of losing perhaps sight of the question and the overall drift of my original post

To paraphrase someone I can't remember, "If someone is having trouble understanding you, it is rarely their fault." Everyone here is doing there best to help you.

 

[russ_watters]

People like me, who, however well educated they may be, are not scientifically trained, can and will make incorrect statements, but it serves no purpose to engage in a display of scientific savvy by dissecting every single word or statement, at the cost of losing perhaps sight of the question and the overall drift of my original post, which was :

why does an obiect in the sky appear to move around very little across the seasons, in spite of the millions of miles traveled by the Earth along its orbit? .. Was this really so difficult to understand?

Yes, it really is difficult to understand. There's two big problems with it right off the start, due to the following facts:

1. All bright celestial objects except Polaris move a lot every night, as the Earth rotates.
2. All bright celestial objects except Polaris move a lot over the course of the year, as the Earth revolves around the sun.

(and Polaris really isn't even all that bright)

It is very difficult to reconcile those two facts with what you said/asked. It's not at all clear if you are taking those motions into account or not. It sounds like you are literally saying you can look out your window at the same time every night and see the same object in almost the same position. Unless that object is Polaris, that simply isn't possible. So in my opinion the question isn't answerable except to say what you describe isn't possible.

However, it *is* very easy to tell that if you look southeast at 11pm tonight, low in the sky, you will see a very bright object. It's Jupiter. Yes, this entire thread should have been able to be asked and answered in two sentences. It should have been that easy.

 

[Ittiandro]

To paraphrase someone I can't remember, "If someone is having trouble understanding you, it is rarely their fault." Everyone here is doing there best to help you.

I am convinced that everyone in his own way is doing his her best to help me and I do appreciate it.
However quoting somebody out of context is not the best way to promote understanding and a constructive dialog ..
In fact, I can quote another " somebody" whom I can't remember who said " Quote somebody out of context and I'll have him hanged !"

If you read more carefully, in the next paragraph I summarized, almost verbatim my original question, in an attempt to show that it was in simple and plain enough English for all to understand an to respond without bemuddling the issue with hair-splitting distinctions about parallax, orbital motions, arcseconds, etc. , ,.

These distinctions are absolutely correct, but I also believe they are also, in way, a red herring, irrelevant to my question.
I outlined four possible, logically envisageable ways in which my question could have been answered
Somebody did understand me after all, because I got plausible answers which went a long way to convince me that I was perhaps wrong in my perception,

 

[DaveC426913]

However, it *is* very easy to tell that if you look southeast at 11pm tonight, low in the sky, you will see a very bright object. It's Jupiter. Yes, this entire thread should have been able to be asked and answered in two sentences. It should have been that easy.

Well, except for the part about seeing it in the same place in winter as in summer, as the OP has stated.

 

[russ_watters]

Well, except for the part about seeing it in the same place in winter as in summer, as the OP has stated.

Right, so that part is simply impossible. Which means that it is possible the question is unanswerable.

However, I'd tend to give a pass on memory issues regarding the night sky. I've heard a lot of memories of what was seen that wasn't possible/true. We can't really help with that, but we can identify a bright object seen *today* with nearly absolute certainty, given enough/correct information.

 

[Drakkith]

If you read more carefully, in the next paragraph I summarized, almost verbatim my original question, in an attempt to show that it was in simple and plain enough English for all to understand an to respond without bemuddling the issue with hair-splitting distinctions about parallax, orbital motions, arcseconds, etc. , ,.

Your original post was concerned mainly about a specific object in the night sky and why it didn't noticeable move as the seasons passed. You spent almost the entirety of your first post talking about it. The first paragraph of that post, which is what you re-wrote just above, is not the full question (or, rather, it's a more general question). This is why so much effort has been spent trying to pin down which object you saw.

Everything about parallax and orbital motions is just general information on why and how things move in the sky, which mostly answers your more general question that was the first paragraph of your first post.

 

[Ittiandro]

Yes, it really is difficult to understand. There's two big problems with it right off the start, due to the following facts:

1. All bright celestial objects except Polaris move a lot every night, as the Earth rotates.
2. All bright celestial objects except Polaris move a lot over the course of the year, as the Earth revolves around the sun.

(and Polaris really isn't even all that bright)

It is very difficult to reconcile those two facts with what you said/asked. It's not at all clear if you are taking those motions into account or not. It sounds like you are literally saying you can look out your window at the same time every night and see the same object in almost the same position. Unless that object is Polaris, that simply isn't possible. So in my opinion the question isn't answerable except to say what you describe isn't possible.

However, it *is* very easy to tell that if you look southeast at 11pm tonight, low in the sky, you will see a very bright object. It's Jupiter. Yes, this entire thread should have been able to be asked and answered in two sentences. It should have been that easy.

Point well taken!
I knew, though, that bright objects in the sky ( except Polaris) move, both because of the Earth’s rotation and the Earth’s revolution. In fact, what prompted me to start the thread was that I was surprised not that they move, but that they move so little, especially considering the millions of miles traveled by the Earth in its orbit. !

I think that the only way out of this quandary is for me to admit that perhaps I am not looking at the same object within the span of a few hours during the night. Also, when I say that the very same object appears to be visible in winter and summer with a very little change in its position in the sky, I am told that this is not possible and I begin to realize why.

But then it is not because you don’t understand me..You do understand me pretty well. What you mean is that I am wrong in assuming that it is the same object. It would have been lot better to say this at the onset and show me why at the onset, rather than dwelling on issues like the parallax, angular radius, arcseconds etc …

Ittiandro…

 

[Drakkith]

But then it is not because you don’t understand me..You do understand me pretty well. What you mean is that I am wrong in assuming that it is the same object. It would have been lot better to say this at the onset and show me why at the onset, rather than dwelling on issues like the parallax, angular radius, arcseconds etc

No one knew this until much further along in the thread. Dave started to get an idea of what you meant with post #13, but even then he was still asking questions to make sure that's really what you were saying. Vela was still uncertain even later, as post #18 shows. I still wasn't sure your question had been answered satisfactorily in post #20.

Stop acting like your a victim here.

 

[Vanadium 50]

It would have been lot better to say this at the onset and show me why at the onset, rather than dwelling on issues like the parallax,

You were the one who dragged in parallax.

I'm with Drakkith. Stop acting like a victim.

 

[sophiecentaur]

However, it *is* very easy to tell that if you look southeast at 11pm tonight, low in the sky, you will see a very bright object. It's Jupiter.

. . . . . and, for those of you in Australia ?

But there's nothing worse than when the OP is very unspecific and all the contributors read it differently and then the questioner takes offence. There are some brilliant threads that start off with a well crafted question and are followed by a set of highly relevant and well informed answers. We all go home happy (and better informed) in those cases.

I don't know how many of you have found yourself in a Plumbing or Building forum and seen the rough treatment that 'beginners' get. That's one good thing about PF - no blood gets spilled.

 

[russ_watters]

. . . . . and, for those of you in Australia ?

Fortunately I'm in Philadelphia which isn't far enough from Quebec to matter for this question and example.

I don't know how many of you have found yourself in a Plumbing or Building forum and seen the rough treatment that 'beginners' get. That's one good thing about PF - no blood gets spilled.

Yeah, I'm a registered professional mechanical engineer and I went to a popular electrical forum to ask a question that overlaps the two disciplines and they just hammered me about it -- questioning whether I was fit to be licensed. It was brutal and I haven't been back.

 

[Ittiandro]

Your original post was concerned mainly about a specific object in the night sky and why it didn't noticeable move as the seasons passed. You spent almost the entirety of your first post talking about it. The first paragraph of that post, which is what you re-wrote just above, is not the full question (or, rather, it's a more general question). This is why so much effort has been spent trying to pin down which object you saw.

Everything about parallax and orbital motions is just general information on why and how things move in the sky, which mostly answers your more general question that was the first paragraph of your first post.

I see that we are reaching a common ground..
The confusion arose not so much from a lack of clarity of what I was saying from the point of you of language, as from the very premisses of my post, one of which I now believe it was wrong.
1. I could not identify that object.
2. I assumed that I was seeing the same object throughout the night and throughout the seasons, in spite of the orbital motion of the Earth. The reason for this assumption was that this body seemed to hover around in an almost circular motion with a radius contained within the span of only three or four hands, admittedly a very crude measurement, but I couldn't do better.So I though it was the same object. It didn't certainly help that I couldn't be more precise.

While I couldn't do anything to identify that object, I must admit that I may have been plainly wrong in the 2nd premiss.
I think that I was not looking at the same object. Somebody in this Forum gave me compelling reasons for this and I won't argue . You people know more than me about astronomy.
Perhaps the fact that those two bodies,( which I initially mistakenly took for the same body ) cropped up almost in the same location, was a mere coincidence.

I thank you all for your help

Ittiandro

PS: Just after posting this , I received a comment from somebody asking me to stop acting like a victim.
I didn't even bother to see who sent this comment. Whoever he is , I believe that what I just said in this post proves this contention wrong.

 

[DaveC426913]

Yeah, I'm a registered professional mechanical engineer and I went to a popular electrical forum to ask a question that overlaps the two disciplines and they just hammered me about it -- questioning whether I was fit to be licensed. It was brutal and I haven't been back.

I feel a little better now. I went to a photog forum to get some ideas about how I could extend the ability to do macro work with my point-n-shoot camera and got "if you won't spend the money, just live within your limits". Thanks, guys.

 

[russ_watters]

Point well taken!
I knew, though, that bright objects in the sky ( except Polaris) move, both because of the Earth’s rotation and the Earth’s revolution. In fact, what prompted me to start the thread was that I was surprised not that they move, but that they move so little, especially considering the millions of miles traveled by the Earth in its orbit. !

That's still a very poor description that doesn't make it clear what motions you are or aren't taking into account. On the one hand you are acknowledging that they move due to Earth's rotation and revolution, then you suggest "they move so little" which is basically the exact opposite statement. Other than the circumpolar stars (which are few), *all* stars and planets traverse basically the entire sky every day/night -- and every year, just different timing.

So whatever you mean by "move so little", it doesn't seem to reflect any observational reality that I can tell.

but that they move so little, especially considering the millions of miles traveled by the Earth in its orbit.

In point of fact, all of the observed motion of the stars happens in one day, every day, during which time the Earth moves very little. Take even the sun as an example; it rises in the east in the morning and sets in the west in the evening. All of that motion happens due to Earth's rotation, not due to the motion of Earth in its orbit.

If we eliminate the Earth's rotation, we're left with the Earth's revolution in its orbit, and motions over the course of a year. And, in another important fact: the so-called "motion" of the stars over the course of a year(the fact that you see different stars in winter vs summer) is simply an artifact of our system of keeping time, which has the sun fixed and the stars moving due to the Earth's orbit. Astronomers use a different system, by which the stars don't move at all, and the sun does.

But again, it isn't clear to me if you are accounting for either of those motions or not.

I think that the only way out of this quandary is for me to admit that perhaps I am not looking at the same object within the span of a few hours during the night. Also, when I say that the very same object appears to be visible in winter and summer with a very little change in its position in the sky, I am told that this is not possible and I begin to realize why.

I'm glad you are starting to understand. I would still encourage you to put more effort into your observation in order to reinforce it. If you are indeed seeing different objects at different times of the night or year, the solution to that is to pay more attention. Have you downloaded a sky map program/app yet...? Ultimately, your ability to articulate what you are seeing won't matter much if you have and use an app that you can literally point at the object and it'll tell you exactly what you are looking at.

 

[DaveC426913]

Have you downloaded a sky map program/app yet...?

OP doesn't even need to download anything.

I got all those maps simply by going to this free online skymap: https://stellarium-web.org/ on my computer.
Set location, date and time and poof!

 

[Ittiandro]

Right, so that part is simply impossible. Which means that it is possible the question is unanswerable.

The inference you make in the 2nd part from the 1st part is logically faulty: even though my post raised a question based on the wrong premise ( I was looking at the same body) , this question was fully answerable! How was it answerable? Simply by saying and showing ( as somebody eventually did) that it was IMPOSSIBLE that I was looking at the same body . This came up only much later and I accepted it, without arguing . .

The fact that, in your case, a bunch of scientifically untrained individuals in a popular electrical forum had the brash to question the knowledge of a fully competent, university educated mechanical engineer like you, cannot be brought to bear on our discussion because I ( the scientifically " uneducated" OP) never had the brash ( and, I'd say the stupidity..), to argue back that it must be the same body .
On the contrary I admitted that I was wrong( and I would have readily admitted it) if only this answer was brought up after my first post. .
This discussion has strayed from one about science to one about language and it is very difficult, if not impossible, to keep both feet in one shoe...

 

[Vanadium 50]

You going to keep complaining about people who generously devoted their time to help you? Do you think this will make things more likely or less likely that people will help you in the future.

You brought up parallax. Then complained that we did. Not cool.

Furthermore, you yourself brought up the point that this was not a sensible motion. You said "I’d expect to see this body at almost diametrically opposed points of the compass at the winter and summer solstices." People agreed that this was not a sensible motion over and over until you finally accepted it - two days and 45 messages later. And somehow this is our fault?

 

[berkeman]

Thread closed for Moderation...

Thread will remain closed. Thank you everybody for trying to help the OP.