Can Polaris be seen from the Australian tropics?

Question

According to The Flat-Earth Conspiracy By Eric Dubay , Polaris can be seen, up to approximately 23.5 degrees South latitude.

That latitude is the Tropic of Capricorn which crosses through (the Northern part of) Australia.

Setting aside the bigger question of whether the Earth is flat, is it true that Polaris can be seen from a latitude that far south - e.g. in Northern parts of Australia?

Well, first, ask them for their evidence. Those books (either Dubay's or Rowbotham's) don't count. As for this question, what kind of evidence would you accept as a good answer? I know there are several Australian users on this site, but unfortunately we can't just ask them to look outside tonight and tell us what they see, as that would be original research which is not acceptable on this site. — Reinstate Monica -- notmaynard, Apr 27 '17 at 21:56
The bottom line is "No, Polaris is not visible from Australia because the Earth is round and Australia is on the wrong side of it.". Seems pretty straightforward to me. — DJClayworth, Apr 27 '17 at 22:06
@DJClayworth I think that's wrong: part of Australia is above the tropic of Capricorn, so Polaris is visible there for part of the year. — ChrisW, Apr 27 '17 at 22:52
Same question elsewhere on network: [Can you still see Polaris even if you are in the south pole?](https://astronomy.stackexchange.com/questions/16427/can-you-still-see-polaris-even-if-you-are-in-the-south-pole) — Batman, Apr 27 '17 at 22:54
@ChrisW The Tropic of Capricorn is too far south. There are no confirmed sighting of Polaris more than 1 degree south (atmospheric refraction and terrain give some leway, but normally you can't see it even at the equator, because it is too dim that low on the horizon). The book either lies or talks about false claims. — Batman, Apr 27 '17 at 23:01
Oh you're right: the Earth is titled relative to its orbit round the sun, not relative to Polaris. — ChrisW, Apr 27 '17 at 23:04
The Earth isn't flat, because you can't see Polaris from Australia, because the Earth isn't flat - that is circular reasoning and is inappropriate for an answer. — Oddthinking, Apr 28 '17 at 02:40
@Oddthinking a) That's why I made it a comment, but b) The OP specifically didn't ask about the flat earth, so it's not circular reasoning. It's absolutely reasonable to take a known and provable fact (The Earth is round) and deduce from it that Polaris cannot be seen from Australia. — DJClayworth, Apr 28 '17 at 17:54

David Hammen · Accepted Answer · 2018-08-31T11:25:40.723

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The current night sky as seen from Nairobi, Kenya (1°17′ south latitude) and from Darwin, Australia (12°27′ south latitude) are shown below.

Nairobi, Kenya night sky:

Darwin, Australia night sky:
^{Sources: https://www.fourmilab.ch/cgi-bin/Yoursky}

Nairobi, Kenya is just south of the equator, so at the right time of the year (this is the right time of the year), Polaris is barely visible in the Nairobi nighttime sky. It's the star just above the "N" (for "North") at the very bottom of the first image. Polaris would not be visible from Nairobi if the Earth had no atmosphere. But it does have an atmosphere. Atmospheric refraction enables us to see objects 34 arc minutes below the horizon. This below the horizon viewing is built-in in modern star chart software.

A tiny bit of Ursa Minor (the Little Dipper) is visible at this time of year from Darwin, Australia. Polaris is not a part of the picture as seen from Darwin. While parts of Ursa Minor can indeed be seen from the northern portions of Australia, Polaris cannot. At a bit over 12 degrees south latitude, all one can see of Ursa Minor are the bright stars Kochab and Pherkad -- but not Polaris.

Polaris can be seen, however, up to approximately 23.5 degrees South latitude.

This was a lie 160 years ago when first issued by Samuel Rowbatham. It remains a lie to this day. It would have been hard 160 years ago to find someone had been to Australia and came back to tell the tale. That's not the case nowadays. You don't even have to fly around the globe. The internet is good enough.

People all over the world use tools such as the site referenced above to look at the night sky. They see exactly what those star charts suggest they will see. I myself have seen Polaris very high in the nighttime sky in Stockholm, and the Southern Cross very high in the nighttime sky in Buenos Aires. I did not see the Southern Cross in Stockholm, nor did I see Polaris from Buenos Aires.

edited Aug 31 '18 at 11:25

answered Apr 28 '17 at 05:53

David Hammen

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For those of use unfamiliar with this, can you tell us where to find Polaris on the first chart? – Oddthinking Apr 28 '17 at 06:08
@Oddthinking at the bottom just above the N – Rigop Apr 28 '17 at 08:00
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@Oddthinking -- I edited Rigop's comment into my answer 18 minutes before he made it. – David Hammen Apr 28 '17 at 08:08
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Uh, are you sure? Astronomy clearly isn't my strong suit, but isn't that star just above the N actually [Yildun/Delta Ursae Minoris](https://en.wikipedia.org/wiki/Delta_Ursae_Minoris). I don't think Polaris is on the top map, but I am ready to shown wrong - a reference would help. – Oddthinking Apr 28 '17 at 14:22
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I think that @Oddthinking is correct - Polaris is the 3rd star in the handle of the little dipper. The top map cuts off after the 2nd star in the handle. Polaris appears to be just below the horizon this time of year even in Nairobi, a good deal more north than Australia. – KAI Apr 28 '17 at 14:34
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The 23.5 degrees number has got to correspond to a spherical cow model of a spherical Earth with no atmospheric effects and no obstructions on the horizon. It is immediately clear that some has to be deducted for the oblateness of the Earth, atmospheric effects and so on. But I find myself surprised that it amounts to 12 degrees. Do you know, off hand, what is the largest contributions? – dmckee --- ex-moderator kitten Apr 30 '17 at 18:42
@Oddthinking is right. Sources: https://upload.wikimedia.org/wikipedia/commons/c/cb/Ursa_Minor_IAU.svg https://en.wikipedia.org/wiki/Delta_Ursae_Minoris – jcsahnwaldt Reinstate Monica Aug 30 '18 at 21:08
Regarding the proposed edit that says that Polaris is not observable, even from Nairobi: It ignores atmospheric refraction, which enables one to see objects about 34 arc minutes below the horizon. This means that at the right time of year, Polaris apparently is just above the horizon. – David Hammen Aug 31 '18 at 11:07
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@DavidHammen - Thanks for the clarification about atmospheric refraction! But the image for Nairobi does not show Polaris. The star just above the N is [Yildun/Delta Ursae Minoris](https://en.wikipedia.org/wiki/Delta_Ursae_Minoris), as Oddthinking correctly pointed out. Polaris is the third star in the "handle" of the Little Dipper and would be slightly to the right of the N - just outside the image. – jcsahnwaldt Reinstate Monica Aug 31 '18 at 11:34
Polaris can only be visible in Nairobi when most of Ursa Minor isn't. [View on theskylive.com](https://theskylive.com/planetarium?localdata=-1.28333%7C36.8167%7CNairobi%2C+Kenya%7CAfrica%2FNairobi&obj=&aobj%5B%5D=sun&aobj%5B%5D=moon&aobj%5B%5D=mercury&aobj%5B%5D=venus&aobj%5B%5D=mars&aobj%5B%5D=jupiter&aobj%5B%5D=saturn&aobj%5B%5D=uranus&aobj%5B%5D=neptune&aobj%5B%5D=pluto&h=23&m=40&date=2018-08-30#ra|0.380581472649041|dec|86.70299297215793|fov|28) – jcsahnwaldt Reinstate Monica Aug 31 '18 at 11:48
@jcsahnwaldt - You chose the wrong time of year. Use [February](https://theskylive.com/planetarium?localdata=-1.28333%7C36.8167%7CNairobi%2C+Kenya%7CAfrica%2FNairobi&obj=sun&aobj%5B%5D=sun&aobj%5B%5D=moon&aobj%5B%5D=mercury&aobj%5B%5D=venus&aobj%5B%5D=mars&aobj%5B%5D=jupiter&aobj%5B%5D=saturn&aobj%5B%5D=uranus&aobj%5B%5D=neptune&aobj%5B%5D=pluto&h=00&m=40&date=2019-02-01#ra|0.380581161280368|dec|86.70299274716784|fov|27.850000000000005) instead. – David Hammen Aug 31 '18 at 12:00
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In any case, Polaris is never visible from any part of Australia. – David Hammen Aug 31 '18 at 12:03
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@DavidHammen The point is that Polaris is not shown on your image for Nairobi. The statement "It's the star just above the N" is wrong. The link to theskylive.com was only an example to prove that some software *does* show Polaris as visible from Nairobi. – jcsahnwaldt Reinstate Monica Aug 31 '18 at 12:17
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In your February link, the center of Polaris is below the horizon. But maybe my statement was not quite correct. I should have said something like "height above horizon of Polaris in Nairobi is negatively correlated to height above horizon of most of Ursa Minor". Anyway, that's not the point. The point is that your answer is not quite correct and it would be easy to fix it. :-) – jcsahnwaldt Reinstate Monica Aug 31 '18 at 12:19

Can Polaris be seen from the Australian tropics?

1 Answers1