Some questions about Polaris (the pole star)

remcot · Jun 19, 2006

Hello,i have some questions about the pole star. 1 What kind of star is Polaris? I always thought it was a (Sun)like star. 2 What will be the difference to be at 1 AU away from Polaris and 1 AU away from the Sun? Will it be cooler or warmer? 3 Our Sun is shining at (about) magnitude -26.50 here on Earth ,if a planet orbits Polaris at a distance where it shines (also) at magnitude -26.50 will it give less ,the same or just more heat and radiation? Can somebody answer this questions? A lot of thanks. remcot

vogon13 · Jun 19, 2006

1. It was observed as a cepheid, but the brightness oscillations have died out. 2. Drastically warmer! <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

qso1 · Jun 19, 2006

The links below should help out. http://www.jimloy.com/astro/polaris.htm http://en.wikipedia.org/wiki/Polaris <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

3488 · Jun 20, 2006

Polaris is 2,200 times more luminous than our sun, has a mass 6 times greater than the sun (about two million times the mass of the Earth) has a diameter 30 times that of the Sun, has a spectrum of F7 as against G2 for the sun. It is thought to be only about 200 million years old as against 4.6 billion for the Sun. It is 431 light years away, so we are seeing Polaris today as it was in 1545. Concerning the detailed physics, á UMi A is an F7 supergiant (Ib) or bright giant (II). The two smaller companions are: á UMi B an F3V main sequence star, orbiting in 2700 AU distance, and C a very close dwarf on a 20 AU orbit (must be kept hot by the radiation form the supergiant). If a planet orbits Polaris at 1 AU, it will be vapourized. Even at 50 AU (Pluto's maximum distance from our sun), it would still be far hotter than Mercury or Venus. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

leopold · Jun 20, 2006

<blockquote>In reply to:<hr />Many, if not most, of your questions on the many threads you start sound suspiciously like homework questions. I hope you are not taking advantage of the eagerness many of us here have for answering astronomy-related questions just to get an easy grade in an astronomy class. <hr /></blockquote> My thoughts exactly...those questions set off my internal 'homework' alarms. Sad if it's true <img src="/images/icons/frown.gif" /> By the way, Polaris is 431 LY away, so the light we see now was emitted in 1575, not 1545. Big difference <img src="/images/icons/laugh.gif" />

3488 · Jun 21, 2006

Sorry about that, a silly typo error, I meant 1575. Anyway this does seem to be like a homework question. Anyway I have included an artist impression of the Polaris system. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

3488 · Jun 21, 2006

Sorry about that, a silly typo error, I meant 1575. Anyway this does seem to be like a homework question. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

vandivx · Jun 21, 2006

at least some of us onlookers got some information that we can file away, who knows but it can come usefull sometimes being more forward looking, I am wondering what people in year 2437 will see and if some will discuss on their interplanetarynet forum that they see the pole star as it really was back in the year 2006 and the number will seem to them so dated, same as we look back now on year 1575, how about that for perspective vanDivX <div class="Discussion_UserSignature"> </div>

sponge · Jun 22, 2006

Here you go here is the size difference at roughly the same distance <div class="Discussion_UserSignature"> SPONGE </div>

sponge · Jun 22, 2006

Sorry people i can only improve on the way i post pics on this forum and yes i agree the white surround hurts my eyes aswell <div class="Discussion_UserSignature"> SPONGE </div>

3488 · Jun 22, 2006

I tried to find something like this myself, to demonstrate the size difference between Polaris & the Sun from 1 AU. I think your illustration backs up my point that any planet orbiting 1 AU from Polaris would not survive. Your luminosity figure is slightly higher than the one I quoted (your 2,400 sun power as against my 2,200 sun power) but our size measurements agree however (Polaris just over 19 degrees wide at 1 AU as against the Sun's half a degree, 38 times wider or some 53 million kilometres across as against 1.39 million kilometres across for the sun). Would be interesting to know what the rotational period of Polaris is & wether or not it has star spots & what period of cycle they follow. I believe (from an article a while back) that Polaris may have been ejected from the cluster of stars surrounding Alpha Persei (Mirphak), as Alpha Aurigae (Capella) has been ejected from the Hyades in Taurus & that Alpha Canis Majoris (Sirius) & Beta Aurigae (Menkalinan) are part of the Ursa Major moving group. I wonder if our own sun is part of a large scattered group?? <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

remcot · Jun 23, 2006

Thanks for the very beautifull and interesting images and for the information. I have one last question, 1 At which distance from Polaris do you need to be to get the same heat as we have here at 1 AU distance from the Sun? The Suns magnitude here is about -26.60 and what will be the difference in heat and radiation here on Earth at 1 AU distance from the Sun ,and when you are at a (large) distance from Polaris where it shines at (also) magnitude -26.60? Can somebody answer this last (interesting) question? Thanks for all your great help.

remcot · Jun 24, 2006

Can somebody (try) to answer my last question please? Thanks

silylene old · Jun 24, 2006

remcot, I really think you should do your own homework and your own research, instead of asking others to do it for you. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

bonzelite · Jun 24, 2006

??? who cares if he is asking a homework question or not ??? what does it matter? if there is an information stream available on a specific topic, how is it, and why is it, a blasphemy to ask? what is one supposed to do, then? go to a chat forum on cake baking to ask an astronomy related question? asking questions to others more experienced in astronomy is cheating, then?! and is not allowed?? this is not considered an aspect of research? some of you need to get a life and chill out. this is not some sacred bastion of information and intercommunication between special people. it's an information forum. but i guess i'm wrong in assuming this.

silylene old · Jun 24, 2006

<blockquote>In reply to:<hr />??? who cares if he is asking a homework question or not ??? what does it matter? if there is an information stream available on a specific topic, how is it, and why is it, a blasphemy to ask? what is one supposed to do, then?go to a chat forum on cake baking to ask an astronomy related question? asking questions to others more experienced in astronomy is cheating, then?! and is not allowed?? this is not considered an aspect of research? <hr /></blockquote> How about he uses google, finds some of the score of very excellent websites which discuss astronomy, read up about stars including Polaris, and write about what he has learned on his own? Certainly, if I wanted to know more about Polaris and answer his questions, this is exactly how I would've approached finding the answer. And I am certain that the nice guys who did respond back to him found the data they were looking for, plus those nice pictures, by expending their own effort into doing the research that I just described. Unless his teacher told him to interview experts(he never said this), I think it is a safe assumption that his teacher expected him to do his own research on stars, learn something, and report what he learned. Chrissakes, this is the PROBLEM with American teens progressing into science and engineering nowdays, that they are too damn lazy to make the effort to pursue their own learning, they want everything spoon-fed to them. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

Swampcat · Jun 24, 2006

"...this is the PROBLEM with American teens progressing into science and engineering nowdays, that they are too damn lazy to make the effort to pursue their own learning, they want everything spoon-fed to them." Good point. The general ability to do the research is often more important than the particular subject of the research. Consider all the things one learns while looking for specific answers. <div class="Discussion_UserSignature"> ------------------------------------------------------------------- "I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccessful rebellions, indeed, generally establish the encroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions as not to discourage them too much. It is a medicine necessary for the sound health of government."Thomas Jefferson </div>

bonzelite · Jun 24, 2006

asking enthusiasts and knowledgeable others about polaris, on "space.com," is not a part of doing research and is to be disdained and frowned upon. and when someone does ask something, that one should be scolded for their curiosity and questions. ok, got it. asking questions is not, i repeat, is not part of the learning process on space.com. and anyone inclined to answer someone's question is merely spoon-feeding somebody. and the questioner is lazy and a moral travesty. got it. check. we ought to, then, have nobody else join up on space.com because the information here is not to be read or disseminated. and information not yet posted should not be asked to be posted or requested. check, good buddy. 10/4.

silylene old · Jun 24, 2006

<blockquote>In reply to:<hr />asking enthusiasts and knowledgeable others about polaris, on "space.com," is not a part of doing research and is to be disdained and frowned upon. and when someone does ask something, that one should be scolded for their curiosity and questions. <hr /></blockquote> Let me rephrase your statement: asking enthusiasts and knowledgeable others about polaris, on "space.com," instead doing their own homework as the teacher intended, and looking up the information for themselfis not a part of doing research and is to be disdained and frowned upon. and when someone does ask something, that one should be scolded for their curiosity and questions if they are taking advantage of the generosity of others as a substitute for doing their own work./safety_wrapper> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

sponge · Jun 24, 2006

silylene says: remcot, I really think you should do your own homework and your own research, instead of asking others to do it for you. silylene, your statement go against all discussion forums and especially when remcot posted the thread. If you do not want to answer his questions go to another thread, i myself have asked alot questions on this forum , thats why they have a subject named "Ask the Astronomer" and I have also found that people more educated than myself on particular subjects are more than willing to reply, so dont try and mould other peoples posts with your own rules this is a discussion forum, so just chill out and respect the other members this is not a scientific research centre(That last statement might not be entirely true) <div class="Discussion_UserSignature"> SPONGE </div>

bonzelite · Jun 25, 2006

so what are you saying? this should be a pay-per-question site? this way, the questioner is not "taking advantage" of the one who has the answer? let's enact a new policy, then: no more asking of any questions to anybody who may possess knowledge of the answer. not here. not on SDC. go to another site and ask it. but not here. all memebers who ask others for answers are free-loading immoral slackers and do not deserve an answer for any reason, at any time. let the Shadow know of any errant or rogue questioner, and have them banned. here here. let's see a show of hands for all in favor.

CalliArcale · Jun 25, 2006

I think you're being sarcastic there. I don't think it would be appropriate to do that. After all, asking questions is the number one pursuit of science, and is what draws a great many people over here. Naturally, there is a risk that people will use this site to cheat on their homework, but I try not to think too much about that. After all, why assume the worst of someone you've just met for the very first time? There are lots of reasons people might ask a collection of questions. I also would not want to discourage people from seeking help with homework, although I'd encourage any students to let folks know if you're looking for homework help. If you tell people that you want help with your homework, you'll probably get a more in-depth response. Folks may even share their own stories of school, tips for how to do good research, and explanations to help you get something that you're just not understanding yet from the teacher. I know I've learned a lot here, and I'm not about to stop asking questions myself. <img src="/images/icons/wink.gif" /> Folks, I realize it's a bit irritating to be used by a potential homework cheater. But you don't know this person is a homework cheater. It's worth making a brief post to the effect of what silyene and others so eloquently stated, that it's basically rude to take advantage of people and won't help you out at all in school (especially if your teacher happens to be an Uplink member -- hey, it could happen!). But let's avoid belaboring the point, because just as it's rude to take advantage of the generosity of Uplink members, it's also rude to spurn someone who has just built up a bunch of questions on the fear that they might be homework cheaters. Besides, even if they are a homework cheater, their thread will probably start a very stimulating discussion, and in that case, Uplink is the real winner. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

qso1 · Jun 25, 2006

The questions raised are quite good ones and knowing how little elementary thru high schools pay attention to space travel or astronomy nowadays. If these are homework questions, they are quite advanced astronomy questions. I would encourage a student to ask questions here. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

Swampcat · Jun 25, 2006

bonz, your sarcasm is unbecoming. You have a good point, but your method of expressing it can get old. I have no problem with people using Uplink as an aid in doing their homework, especially if they state that's what they're doing. There are a couple of points, however, that need to be considered. 1) An important skill is learning how to do your own research. As the old adage puts it, give a man a fish and you feed him for a day. Teach him how to fish and you feed him for a lifetime. 2) Uplink is one possible and useful source for research, but there is the question of the qualifications of those giving the answers. There is absolutely no guarantee that the answers you get on Uplink have any scientific basis or are just someone's feelings, beliefs or guesses. There is no snobbery or elitism here, unless you feel challenged in some way by those who have spent more time and effort researching in a disciplined way. There is also the point I made before that getting pat answers often does not provide for the greater understanding that comes while doing the research. If that means going to alternative science websites as well as those of a more traditional approach (or even reading a book or two) then so be it. Only in that way can a person truly judge the truth for themselves. <div class="Discussion_UserSignature"> ------------------------------------------------------------------- "I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccessful rebellions, indeed, generally establish the encroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions as not to discourage them too much. It is a medicine necessary for the sound health of government."Thomas Jefferson </div>

doubletruncation · Jun 25, 2006

1 At which distance from Polaris do you need to be to get the same heat as we have here at 1 AU distance from the Sun? The Suns magnitude here is about -26.60 and what will be the difference in heat and radiation here on Earth at 1 AU distance from the Sun ,and when you are at a (large) distance from Polaris where it shines at (also) magnitude -26.60? Can somebody answer this last (interesting) question? Thanks for all your great help. Hi remcot, You've had a bunch of questions of a similar nature, so I think it might be helpful to go over how you can actually find the answer to this question (and many similar ones). It's quite straightforward really, and I think just as interesting as knowing the actual answer. And once you know how to do it, I think you should be able to find answers by yourself for any of these interesting questions. So the question is: at what distance from Polaris do you need to be to get the same heat as we have here at 1 AU distance from the Sun? This is really an inverse square law question - any question involving what magnitude different stars would appear from different distances is an inverse square law question, because the amount of light that you receive drops off as the square of the distance to the source. So the flux is equal to f = L / (4*pi*d^2) where L is the luminosity of the star (say in Watts), and d is the distance to the star. In practice astronomers use magnitudes for brightnesses since in some sense they're easier to measure than actual fluxes (what I mean is it's a lot easier to measure the brightness relative to another star than it is to measure the flux in say watts/square meter. magnitudes are basically the brightness measured relative to the star Vega, you then take -2.5*log10 of the relative brightness just for kicks, or historical reasons). Ok, so since flux falls off as 1/d^2, we can see how magnitudes behave. If a star has m <div class="Discussion_UserSignature"> </div>

Some questions about Polaris (the pole star)

remcot

Guest

vogon13

Guest

qso1

Guest

3488

Guest

leopold

Guest

3488

Guest

3488

Guest

vandivx

Guest

sponge

Guest

sponge

Guest

3488

Guest

remcot

Guest

remcot

Guest

silylene old

Guest

bonzelite

Guest

silylene old

Guest

Swampcat

Guest

bonzelite

Guest

silylene old

Guest

sponge

Guest

bonzelite

Guest

CalliArcale

Guest

qso1

Guest

Swampcat

Guest

doubletruncation

Guest

Similar threads

TRENDING THREADS

Latest posts

Share this page