<p>One of us has misread the paper because I think he says he plans to use "Benanaim" which seems to be an alternative name for Alkaid, $\eta$ Ursae Majoris and very much "ultima cauda ursae majoris" and which would, indeed, transit the meridian at around 9pm on that date.</p>

CC BY-SA 3.0
2015-02-12T16:29:11.277Z
2015-02-12T16:29:11.277Z
adrianmcmenamin
<p>I am reading Roobert Hooke's paper <em>An attempt to prove the motion of the earth from observations</em> (1674, <a href="http://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=/mpiwg/online/permanent/library/XXTBUC3U/pageimg&amp;start=11&amp;mode=imagepath&amp;pn=18&amp;ww=0.7142&amp;wh=0.7142&amp;wx=0.0277&amp;wy=0.1065" rel="nofollow">faksimile</a>). Hooke writes</p>

<blockquote>
  <p>The principal dayes of doing which will be about the 4 of April, when our Zenith passeth by the said Star at midnight</p>
</blockquote>

<p>The said star is Gamma Draconis, and the observations are made in London. As far as I see it, the star is closest to the Zenit at 6 in the morning in London at April 4th.</p>

<p>So, why does Hooke say <em>at midnight</em>? Is this an expression of the 17th century? </p>

CC BY-SA 3.0
2015-01-19T09:50:19.743Z
That would be April 4th on the Julian Calendar, should be about the 15th April Gregorian. But Gamma Draconis is at the zenith at midnight around 21st June in London.
Conrad Turner
CC BY-SA 3.0
2015-02-12T16:24:40.910Z
Isn't it eta Ursa Majoris?
adrianmcmenamin
<telescope><positional-astronomy><parallax>
When is Gamma Draconis closest to the zenith in London on April 4th
René Nyffenegger
# When is Gamma Draconis closest to the zenith in London on April 4th

(Asked by: username_0 on 2015-01-17)

I am reading Roobert Hooke's paper *An attempt to prove the motion of the earth from observations* (1674, [faksimile](http://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=/mpiwg/online/permanent/library/XXTBUC3U/pageimg&start=11&mode=imagepath&pn=18&ww=0.7142&wh=0.7142&wx=0.0277&wy=0.1065)). Hooke writes

> The principal dayes of doing which will be about the 4 of April, when our Zenith passeth by the said Star at midnight

The said star is Gamma Draconis, and the observations are made in London. As far as I see it, the star is closest to the Zenit at 6 in the morning in London at April 4th.

So, why does Hooke say *at midnight*? Is this an expression of the 17th century?

**Tags:** telescope, positional-astronomy, parallax
> **Comments:**
> **username_1**: That would be April 4th on the Julian Calendar, should be about the 15th April Gregorian. But Gamma Draconis is at the zenith at midnight around 21st June in London.  
> **username_2**: Isn't it eta Ursa Majoris?  

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## 1 answers

### Answer by username_2 on 2015-02-12. Score: 0

One of us has misread the paper because I think he says he plans to use "Benanaim" which seems to be an alternative name for Alkaid, $\eta$ Ursae Majoris and very much "ultima cauda ursae majoris" and which would, indeed, transit the meridian at around 9pm on that date.


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