Questions tagged [right-ascension]
Questions regarding the second ordinate of the equatorial celestial system.
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Measuring misalignment between two positions on sky
Let's say I have the (RA,Dec) for two positions on the sky. I want to measure the position angle between these two positions. In other words, if I had the Cartesian coordinate vectors for these two ...
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Right Ascension to Zodiac House
At the moment (01-04-2020 09:36) the Moon is situated in Gemini:
"The Moon is currently in the constellation of Gemini. The current Right Ascension is 06h 37m 56s and the Declination is +23° 42' 09”."...
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What's the difference between minutes and arcminutes?
I read in trigonometry class that 1 minute is equal to 1/60 degrees. So, 'minute' is an angular unit. But also 'arcminutes' are used to measure seperation between celestial objects and also equals to ...
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Position of Hamal (alpha Arietis) between 1582 and 1588
Between 1582 and 1588, Tycho Brahe observed $\alpha$ Arietis from Uraniborg (55°54′28″N 12°41′48″E) on at least 27 separate occasions and made a record of the right ascension of the star (see Opera ...
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how to plot sky map like www.nakedeyeplanet.com with dates tags with planetary motion path
I am curious how to plot planetary motion star chart with date tags like on www.nakedeyeplanets.com by Martin J. Powell.
Is there any way to generate images similar like that. What software should ...
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Help with Converting Right Ascension and Declination into 3D Vectors
Using the Right Ascension and Declination values from the HYG Database from The Astronomy Nexus:
Right ascension is measured in hours and declination is measured in degrees.
1 - Convert right ...
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What exactly is a Right Ascension clock and how was one (mounted on a telescope) used in practice, historically?
@MikeG's answer to Why does this Lowell Observatory telescope have so many knobs? What do they all do? explains that item #6 labeled in the image there (and cropped version here) is likely to be a "...
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What is the opposite of the vernal point?
The equator and the ecliptic cross at two nodes. One of those nodes is the vernal point. What is the other one called?
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When does a star rise with the sun?
Problem: Suppose an observer's latitude is 45 S and a star's RA/DEC is
3h15min/41S. On what date will the sun set with the star.
I have been stuck on this problem for a while.
I found out that the ...
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Correct units to use while plotting mollweide projection of sky chart with RA and Dec values, matplotlib
I am trying to plot a mollweide projection of a sky chart in Python using the matplotlib package. I am using the RA and Dec values from a database containing all stars in Hipparcos, Yale Bright Star, ...
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