Setup for Spherical Astronomy Problem

In summary, an observer south of the equator would not be able to see the south celestial pole, even though the latitude is positive.
  • #1
Kelli Van Brunt
11
3
Homework Statement
A full moon occurred on June 19, 2008 at 00h 30m West Indonesian Time (local civil time for western part of Indonesia with reference to geographic longitude of 105° E). Calculate the extreme values of duration of the Moon above the horizon for observers at Bosscha Observatory (longitude: 107º 35' 00″.0 E, latitude: 6º 49' 00″.0 S, Elevation: 1300.0 m). Time zone = UT +7h 00m.
Relevant Equations
None; this is a conceptual question
My apologies for not detailing my attempts at a solution; I'm not sure how to to digitally illustrate or describe the various setups I attempted before looking at the solution to this problem. I am also ONLY asking about the setup, though I included the full question for context.
The solution to this problem has the following setup:
QdDFwYBsCbuvMd7hdNkj_j9_Nu4roFXWSE6Sgcd_filFjsOrkw.png


Where Z = zenith, P = south celestial pole, and M = moon (I assume represented by the path of the little blue spheres). SP is the latitude of the observing site and PM is 90º - declination of Moon. My main question is, why is P above the horizon/NESW plane when the latitude of the observing site is positive? Shouldn't an observer in the north not be able to "see" the south celestial pole? I drew a diagram of the situation in the equatorial plane below and am wondering why this is not the correct setup. The horizontal analogy to this would, I assume, be the above diagram but with the moon's path, celestial equator, and celestial south pole shifted clockwise so that M is to the right of the zenith and P is below the horizon. I apologize for my very bad graphic design skills. Can anyone clarify this for me?
pixil-frame-0 (3).png

EDIT: Sorry for posting this twice - that was an accident.
 
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  • #2
Kelli Van Brunt said:
My main question is, why is P above the horizon/NESW plane when the latitude of the observing site is positive? Shouldn't an observer in the north not be able to "see" the south celestial pole?
Bosscha Observatory is south of the equator. Although the latitude was given as an unsigned value, you know that it's south of the equator by the "S" at the end of ... latitude: 6º 49' 00″.0 S.
 
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  • #3
collinsmark said:
Bosscha Observatory is south of the equator. Although the latitude was given as an unsigned value, you know that it's south of the equator by the "S" at the end of ... latitude: 6º 49' 00″.0 S.
I can't believe I missed that, thank you so much. That cleared up everything.
 
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FAQ: Setup for Spherical Astronomy Problem

What is the setup for a spherical astronomy problem?

The setup for a spherical astronomy problem involves using spherical coordinates to map out the position of celestial objects in the sky. This includes using the celestial sphere, which is an imaginary sphere that surrounds the Earth, and using coordinates such as declination and right ascension to pinpoint the location of objects.

Why is spherical astronomy important?

Spherical astronomy is important because it allows us to accurately measure and track the positions of celestial objects in the night sky. This is essential for astronomical observations and calculations, as well as for navigation and timekeeping.

What tools are needed for a spherical astronomy problem?

The main tools needed for a spherical astronomy problem include a telescope, a star chart or app, and knowledge of spherical coordinate systems. Additionally, a good understanding of trigonometry and geometry is important for solving spherical astronomy problems.

How do you convert between spherical and Cartesian coordinates?

To convert between spherical and Cartesian coordinates, you can use the following formulas:

x = r * sin(θ) * cos(φ)

y = r * sin(θ) * sin(φ)

z = r * cos(θ)

Where r is the distance from the origin, θ is the polar angle, and φ is the azimuthal angle.

What are some common applications of spherical astronomy?

Spherical astronomy has a wide range of applications, including celestial navigation, timekeeping, and astronomical calculations. It is also used in fields such as astrophysics, aerospace engineering, and satellite navigation. Additionally, spherical astronomy is important for understanding and studying the motions and positions of celestial objects in our universe.

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