Polaris being bright

[Odinoneeye]

The other night I was out on the beach with my wife, her cousin and some friends. My wife mentioned that the North Star was the brightest star in the sky. I told her it wasn't, then her cousin chimed in saying she had always heard that too.

Well my wife my argue with me about mowing the lawn, but when it comes to science, she knows not to argue with me. I ever explained to her that it was on Badastronomy under "misconceptions"

Anyway, my question is, does anyone know where this myth came from? I've always known it wasn't, so I don't know why so many people would think it was.

Any ideas?

[Hamlet]

The other night I was out on the beach with my wife, her cousin and some friends. My wife mentioned that the North Star was the brightest star in the sky. I told her it wasn't, then her cousin chimed in saying she had always heard that too.

Well my wife my argue with me about mowing the lawn, but when it comes to science, she knows not to argue with me. I ever explained to her that it was on Badastronomy under "misconceptions"

Anyway, my question is, does anyone know where this myth came from? I've always known it wasn't, so I don't know why so many people would think it was.

Any ideas?

I've encountered this a few times myself. I've never read or been taught that Polaris was the brightest star and I've always known that it wasn't. I'm not sure where this myth originates. I wonder if it is possibly a psychological effect? Most people know that Polaris has been used for centuries as a navigation aid and that the other stars seem to rotate about it. It may be that people simply think that a star that is important must also be bright.

It is interesting too that the people who thought Polaris was the brightest didn't have a clue as to how to find it in the sky. I wonder if folks find a bright star and think that it must be Polaris and that sticks in their minds from then on?

I would be very interested to know where this myth originated.

[aporetic_r]

Most people know that Polaris has been used for centuries as a navigation aid and that the other stars seem to rotate about it. It may be that people simply think that a star that is important must also be bright.

At some point when I was a little kid it came into my head - for whatever reason - that the North Star (I didn't know its real name) was the brightest star in the sky. Perhaps one of my parents told me. In any case, for quite a while I simply looked for the brightest star in the sky and figured that must be Polaris. Then at some point I realized that that couldn't possibly be the case, because the star was definitely not acting like a pole star should - not that I knew anything about anything at this point (I was probably around 10 at the time), but I did know that a pole star wouldn't be moving around like the rest of the stars, since that is what makes a pole star so useful.

Aporetic
www.polisci.wisc.edu/~rdparrish

[Matherly]

From personal experience...

I find I know more about astronomy than my wife, even though she is intelligent and inqusitive. I think the biggest problem she has is that she grew up in Houston, and I grew up in the midwest (Omaha... but I spent a lot of weekends at my grandfather's farm). At the farm, I could see a whole mess of stars, while in Houston you can't see many at all. When my dad showed me how to find Polaris, it was painfully obvious that it was no where close to being "the brightest star". While I don't know if my wife ever had that misconception, I can see how someone who can't see the stars worth a spit could think some odd things about them.

[Hamlet]

From personal experience...

I find I know more about astronomy than my wife, even though she is intelligent and inqusitive. I think the biggest problem she has is that she grew up in Houston, and I grew up in the midwest (Omaha... but I spent a lot of weekends at my grandfather's farm). At the farm, I could see a whole mess of stars, while in Houston you can't see many at all. When my dad showed me how to find Polaris, it was painfully obvious that it was no where close to being "the brightest star". While I don't know if my wife ever had that misconception, I can see how someone who can't see the stars worth a spit could think some odd things about them.

I think this may very well explain some peoples perceptions. Folks who grew up in the bright lights of the city may never have seen Polaris and just assumed that one of the bright stars they could see was it.

[gethen]

About a year ago, when I first started visiting here, it was because a group of rather intelligent, reasonably educated people that I had recently met were all thoroughly convinced that Polaris had "burned out" and that the star I was calling Polaris was something else. They treated this as common knowledge, telling me that their kids had learned it in school. I came here looking for the source of such a crazy idea, and the best that anyone came up with was related to this current discussion. Some here suggested that those people might be expecting Polaris to be much brighter than it actually is, so that the star in it's place couldn't be Polaris. Another explanation was related to Polaris' status as a variable star. I eventually convinced the other folks of their error, but was never able to track it down to the original source.
I suspect that people believing that Polaris is the brightest star in the sky is related to the fact that it's the only star most people can name.

[Hamlet]

About a year ago, when I first started visiting here, it was because a group of rather intelligent, reasonably educated people that I had recently met were all thoroughly convinced that Polaris had "burned out" and that the star I was calling Polaris was something else. They treated this as common knowledge, telling me that their kids had learned it in school. I came here looking for the source of such a crazy idea, and the best that anyone came up with was related to this current discussion. Some here suggested that those people might be expecting Polaris to be much brighter than it actually is, so that the star in it's place couldn't be Polaris. Another explanation was related to Polaris' status as a variable star. I eventually convinced the other folks of their error, but was never able to track it down to the original source.

Hmmm. That's very interesting. They actually thought Polaris had burned out? I must have missed that thread or I've forgotten it. How did you finally convince them of their errors? Did you ever find out if the kids had really learned this in school? If you already answered these in the original thread I'll just go and read it.


I suspect that people believing that Polaris is the brightest star in the sky is related to the fact that it's the only star most people can name.

I think there's some truth to that. It may be that they learned about Polaris in school but can't remember why. They may draw the conclusion that it must have been because it was the brightest.

[tracer]

Another explanation was related to Polaris' status as a variable star.
That's a distinct possibility. Polaris A is a Cepheid variable, but its variability is very shallow -- it only brightens and dims by 0.2 magnitudes at most. More importantly, in 1994, its variability vanished altogether. Its variability re-emerged in 1995, but the fact that a Cepheid variable could go through a period of not being variable any more was considered quite significant at the time.

It may have been the "burning out" of Polaris's variability that your buddies conflated with a burning out of the star itself.

[daver]

About a year ago, when I first started visiting here, it was because a group of rather intelligent, reasonably educated people that I had recently met were all thoroughly convinced that Polaris had "burned out" and that the star I was calling Polaris was something else. They treated this as common knowledge, telling me that their kids had learned it in school. I came here looking for the source of such a crazy idea, and the best that anyone came up with was related to this current discussion. Some here suggested that those people might be expecting Polaris to be much brighter than it actually is, so that the star in it's place couldn't be Polaris. Another explanation was related to Polaris' status as a variable star. I eventually convinced the other folks of their error, but was never able to track it down to the original source.
I suspect that people believing that Polaris is the brightest star in the sky is related to the fact that it's the only star most people can name.

My daughter is in summer school (2nd grade); last week she said that she was taught that Quaoar was a newly discovered planet, and the heaviest and the hottest of the lot. She didn't bring home anything printed; i don't know if the school taught it wrong or if she learned it wrong.

[dgruss23]

From my experience, there are very few science teachers and even fewer elementary teachers that are given sufficient training in Astronomy to really be able to teach it. I get questions quite often from elementary teachers in my district regarding astronomy topics. One of the reasons my astronomy course was seen as expendable (and dropped for this upcoming year despite an enrollment of 40 students :evil: ) was that I was the only teacher in my department who could teach it.

Most people get along just fine without knowing any astronomy and since there is limited exposure to the subject in school its not surprising that misconceptions will easily spread.

[AGN Fuel]

The other night I was out on the beach with my wife, her cousin and some friends. My wife mentioned that the North Star was the brightest star in the sky. I told her it wasn't, then her cousin chimed in saying she had always heard that too.

Anyway, my question is, does anyone know where this myth came from? I've always known it wasn't, so I don't know why so many people would think it was.

Any ideas?

I suspect that it is related to the fact that Polaris was crucial for navigation. To the layperson, importance and brightness are two concepts easy to mix-up.

[beskeptical]

I suspect that it is related to the fact that Polaris was crucial for navigation. To the layperson, importance and brightness are two concepts easy to mix-up.

I vote for this option. Folks I teach inf. disease topics to often mix the material up.

[gethen]

As far as the folks thinking Polaris had burned out, I guess what happened was just that I explained to them that if Polaris had "burned out" it would have been pretty big news, and we should have been able to find something about it on the web. Also explained about Polaris being a Ceheid variable, but that it was heading toward losing that designation, which someone might have misinterpreted. I also told them that as Polaris is, I think, a red-supergiant, it probably will not just "burn out," but will have a more spectacular end. Since they'd been accepting this bit of disinfo for a couple of years, they were a little unsure as to the exact child or teacher who got it started.

[ToSeek]

I suspect that it is related to the fact that Polaris was crucial for navigation. To the layperson, importance and brightness are two concepts easy to mix-up.

I vote for this option. Folks I teach inf. disease topics to often mix the material up.

I concur.

[Kaptain K]

As far as the folks thinking Polaris had burned out, I guess what happened was just that I explained to them that if Polaris had "burned out" it would have been pretty big news, and we should have been able to find something about it on the web. Also explained about Polaris being a Ceheid variable, but that it was heading toward losing that designation, which someone might have misinterpreted. I also told them that as Polaris is, I think, a red-supergiant, it probably will not just "burn out," but will have a more spectacular end. Since they'd been accepting this bit of disinfo for a couple of years, they were a little unsure as to the exact child or teacher who got it started.
Polaris is a F7 blue giant/supergiant. Although its brightness variations ceased (or greatly diminished), it continued to vary in diameter and radial velocity. 8)

[tracer]

Since when does F7 qualify as "blue"? That's smack-dab in the middle of yellow-white.

[gethen]

Polaris is a F7 blue giant/supergiant. Although its brightness variations ceased (or greatly diminished), it continued to vary in diameter and radial velocity. 8)

I stand corrected. So how would you expect Polaris to end it's life?

[sol_g2v]

Polaris is a F7 blue giant/supergiant. Although its brightness variations ceased (or greatly diminished), it continued to vary in diameter and radial velocity. 8)

I stand corrected. So how would you expect Polaris to end it's life?

I would expect it to die as a massive white dwarf like Sirius-B.

[tracer]

Ya don't think Polaris has enough mass to go the fusion-of-iron route, or for its core to exceed the Chandrasekhar Limit?

[sol_g2v]

Ya don't think Polaris has enough mass to go the fusion-of-iron route, or for its core to exceed the Chandrasekhar Limit?

According to this (http://arXiv.org/abs/astro-ph/0002406) paper, mass of Polaris is 6.0+or-0.5 solar mass, making it not really massive enough to become a supernova.

[jokergirl]

I think this amounts to a proof of me being an astronomy geek-girl (though I actually don't study this or anything): I remember having a big fight about this with some roommate of mine on a sports camp when I was about 13 or something. The other girl was actually then asking a teacher whether Polaris was the brightest star or not and he agreed with her that it was! Man I was so pissed...

;)

[Hamlet]

I think this amounts to a proof of me being an astronomy geek-girl (though I actually don't study this or anything): I remember having a big fight about this with some roommate of mine on a sports camp when I was about 13 or something.

I remember having fights like this with my best friend when we were teenagers. He didn't have much interest in science but he would occasionally latch on to something he saw on television or read in the newspaper. The problem was he didn't always understand what was being reported or its implications and the conclusions he drew from them were often erroneous. The one argument that stands out was his insistance that the Space Shuttle used its Main Engines during landing. I tried to explain that the shuttle was a glider but he just couldn't conceive how a spacecraft could glide from orbit to the ground and land exactly where we wanted it.


The other girl was actually then asking a teacher whether Polaris was the brightest star or not and he agreed with her that it was! Man I was so pissed...

;)

I would have been upset too! Was this a science teacher?

[Normandy6644]

My daughter is in summer school (2nd grade); last week she said that she was taught that Quaoar was a newly discovered planet, and the heaviest and the hottest of the lot. She didn't bring home anything printed; i don't know if the school taught it wrong or if she learned it wrong.

I think I remember reading about that planet in some magazine awhile back. I'm pretty sure that it is the "heaviest and hottest" planet, though it's OUTSIDE our solar system. Could be that the teacher read that but mistook it for being in our solar neighborhood instead of orbiting whatever star it does. I don't remember the details, but I'm pretty sure that Quaoar is extrasolar.

[kilopi]

I think I remember reading about that planet in some magazine awhile back.
I got it here on the internet somewhere...where did I put that??

Here it is, Quaoar (http://www.gps.caltech.edu/~chad/quaoar/), Kuiper belt object inside our own solar system.

[tracer]

I'm pretty sure that it is the "heaviest and hottest" planet, though it's OUTSIDE our solar system.
At 1250 km in diameter, Quaoar doesn't exactly qualify as the heaviest planet -- and with an orbital radius of 42 AU away from our own sun (and I say radius here, not merely semimajor axis, 'cause its eccentricity is a teeny tiny 0.04), I'd hesitate to guess that it's the hottest planet, either.

Especially since it's not a planet at all but a KBO. :P

[AGN Fuel]

I'm pretty sure that it is the "heaviest and hottest" planet, though it's OUTSIDE our solar system.
At 1250 km in diameter, Quaoar doesn't exactly qualify as the heaviest planet -- and with an orbital radius of 42 AU away from our own sun (and I say radius here, not merely semimajor axis, 'cause its eccentricity is a teeny tiny 0.04), I'd hesitate to guess that it's the hottest planet, either.

Especially since it's not a planet at all but a KBO. :P

I think that by definition you may have trouble arguing that it is outside of our solar system also, given the KBO's orbit the sun. :-s

[Normandy6644]

Especially since it's not a planet at all but a KBO. :P

Well, I knew I read about it somewhere. I guess I didn't remember it all that well. :-? Oh well. Thanks for the info Fuel!

[tracer]

Of course, I always say the same thing about Pluto....

[BobtheEnforcer]

Ya don't think Polaris has enough mass to go the fusion-of-iron route, or for its core to exceed the Chandrasekhar Limit?

According to this (http://arXiv.org/abs/astro-ph/0002406) paper, mass of Polaris is 6.0+or-0.5 solar mass, making it not really massive enough to become a supernova.

I may be wrong here, but I thought that over 3 solar masses = black hole (supernova), 1.4 -3 solar masses = neutron star, and that under 1.4 = white dwarf (Chandrasekhar Limit). ?

[Tobin Dax]

Bob, I don't remember the exact values, but stars do lose mass in their death throes before they go supernova and collapse (if they do). Even sun-like stars blow off the shell of their Red Giant stage to leave the white dwarf core behind.

[sol_g2v]

Ya don't think Polaris has enough mass to go the fusion-of-iron route, or for its core to exceed the Chandrasekhar Limit?

According to this (http://arXiv.org/abs/astro-ph/0002406) paper, mass of Polaris is 6.0+or-0.5 solar mass, making it not really massive enough to become a supernova.

I may be wrong here, but I thought that over 3 solar masses = black hole (supernova), 1.4 -3 solar masses = neutron star, and that under 1.4 = white dwarf (Chandrasekhar Limit). ?

True, but all these objects are the stellar core remnants of stars which have gone through the full cycle of stellar evolution. Stars lose alot of mass after leaving the main-sequence, the bigger the star, the greater the mass loss.

[Charlie in Dayton]

...I remember hearing that Polaris was the brightest star in that general (and rather limited)area. That's why it's kinda eye-catching. But by no means is it the brightest star in the sky. I'm having a senior moment here (I'm old enough to call brain f*rts by that appelation now) -- which one is brightest? Sirius, ain't it?

[AGN Fuel]

...I remember hearing that Polaris was the brightest star in that general (and rather limited)area. That's why it's kinda eye-catching. But by no means is it the brightest star in the sky. I'm having a senior moment here (I'm old enough to call brain f*rts by that appelation now) -- which one is brightest? Sirius, ain't it?

From memory, Polaris is about the 50th brightest star in the night sky, although it is the brightest in Ursa Minor. Sirius is the brightest, followed by Canopus and then our southern hemisphere beacon, Alpha Centauri. 8)

[kilopi]

From memory, Polaris is about the 50th brightest star in the night sky, although it is the brightest in Ursa Minor. Sirius is the brightest, followed by Canopus and then our southern hemisphere beacon, Alpha Centauri.
This list (http://www.astro.utoronto.ca/~garrison/oh.html) says it's 27th, which means it would just not make this list (http://www.astro.wisc.edu/~dolan/constellations/extra/brightest.html), but this list (http://www.astro.wisc.edu/~dolan/constellations/extra/brightest.html) puts it much farther down, around 50th.

PS: Oops, that first list is obviously not ordered by visual magnitude. My bad. Here's a more readable list (http://www.cosmobrain.com/cosmobrain/res/brightstar.html), that places it 48th.

[AK]

PS: Oops, that first list is obviously not ordered by visual magnitude. My bad. Here's a more readable list (http://www.cosmobrain.com/cosmobrain/res/brightstar.html), that places it 48th.

Interesting that that list places Arcturus 3rd and Alpha Centauri 4th... I usually see it listed the other way around.

[AGN Fuel]

PS: Oops, that first list is obviously not ordered by visual magnitude. My bad. Here's a more readable list (http://www.cosmobrain.com/cosmobrain/res/brightstar.html), that places it 48th.

Interesting that that list places Arcturus 3rd and Alpha Centauri 4th... I usually see it listed the other way around.

Yes, that is unusual. The v.mag I normally see quoted for Alpha Centauri is -0.28, which would place it comfortably in third spot. I do note that whoever created that list has only made note of one of the two stars that forms the binary system - maybe that v.mag of -0.01 that he quotes is just for the one star? :-s

[AK]

Yes, that is unusual. The v.mag I normally see quoted for Alpha Centauri is -0.28, which would place it comfortably in third spot. I do note that whoever created that list has only made note of one of the two stars that forms the binary system - maybe that v.mag of -0.01 that he quotes is just for the one star? :-s

Yeah, apparently the -0.01 is for Alpha Centauri A only. B shines at magnitude 1.3 and C at magnitude 11.

From space.com:
When night falls and the skies are clear, the Alpha Centauri system shines at a magnitude of –0.27 low in the southern sky during the summer months. You can find it at the foot of the Centaur in the constellation of Centaurus.

So the -0.27 is for the whole system.

[AGN Fuel]

Yes, that is unusual. The v.mag I normally see quoted for Alpha Centauri is -0.28, which would place it comfortably in third spot. I do note that whoever created that list has only made note of one of the two stars that forms the binary system - maybe that v.mag of -0.01 that he quotes is just for the one star? :-s

Yeah, apparently the -0.01 is for Alpha Centauri A only. B shines at magnitude 1.3 and C at magnitude 11.

From space.com:
When night falls and the skies are clear, the Alpha Centauri system shines at a magnitude of –0.27 low in the southern sky during the summer months. You can find it at the foot of the Centaur in the constellation of Centaurus.

So the -0.27 is for the whole system.

Thanks AK - that explains it. :D Although, it is strange that the author appears to include the combined magnitudes for other multiple star systems in his list, but not for poor old Rigil Kent! :cry:

[kilopi]

Although, it is strange that the author appears to include the combined magnitudes for other multiple star systems in his list, but not for poor old Rigil Kent!
Well, Rigil Kent is treated properly then. Perhaps the author of the list got emails about it, because it was one of the front runners, and is just unaware of the others.

[AGN Fuel]

Although, it is strange that the author appears to include the combined magnitudes for other multiple star systems in his list, but not for poor old Rigil Kent!
Well, Rigil Kent is treated properly then. Perhaps the author of the list got emails about it, because it was one of the front runners, and is just unaware of the others.


I suppose it depends on the purpose of the list. If it is purely the v.mag of the individual stars, then obviously I agree. However, if the list is designed to identify the brightest stars in the night sky as observed by someone wandering out into their back yard & looking up, then the combined v.mag of the stars in the system is appropriate. On that basis, Alpha Cen. should come in third. :wink: