Questions tagged [declination]
Questions regarding one of the two main angles(coordinates) of an object perceived by an observer on Earth.
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How do we derive the sun's declination using right ascension?
It appears that there are 2 formulas to derive the sun's declination.
One is: $declination \approx 23.5 \times sin(\alpha)$ from the answer here
and another which is similar $\delta=−23.45°×cos(\frac{...
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Apparent RA-Dec value with geocentric observer didnt match between Skyfield and Horizons
When I trying to match between Skyfield and Horizons JPL data (with observer in geocentric), I found that the both value have differences. Here's configurations I have:
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The Moon's topocentric position
I followed The Moon's topocentric position to lern how to calculate the moon's position.
I have calculated topocentric RA and Decl, but I don't know how to convert it to the moon's horizon ...
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Know the right ascension and declination of a star in the past using the Hipparcos catalogue
I'm using the Hipparcos catalogue in a software that I'm developing and I'm wondering if it is possible to know the RA and DEC of a star in the past or in the future. Maybe using the Parallax value.
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What's the name of the projection onto the celestial sphere of the tropic of cancer?
The projection of earth's equator is the celestial equator. The ecliptic oscillates above and below it in a year, and the furthest north it goes is the projection onto the celestial sphere of the ...
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calculate declination and right ascension with limited information
I'm trying to make a game with high accuracy moon position so I followed some equations on geoastro.de Basics of Positional Astronomy and Ephemerides and with some help from the questions answers, I ...
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How does azimuth of moonrise/moonset vary by longitude?
I found a useful formula for calculating the azimuth of moonrise/moonset, which can be found in this post:
How does moonrise/moonset azimuth vary with time?
However the formula refers to the fixed ...
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Sidereal time of rising and setting of the sun on the arctic circle
$$
cos(h)= -tan(\delta)tan(\phi)
$$
$$
\Theta = h + \alpha
$$
if these two equations are the correct equations to solve the following question why doesnt it yield the same answer for the sideral ...
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How to even approach this type of question
Can someone tell me how one would approach this type of question. is there an equation we would use or something of the sort.
Ths solution to this question is given below but I just want to understand ...
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Definition for Day Angle
I am searching for a proper definition for day angle.
The day angle $\Gamma$ is calculated as follows:$$\Gamma = 2\pi\cdot \frac{n_{day} - 1}{365}$$
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Plotting galactic latitude in Ra vs Dec plane
I have an open cluster with calculated percentage of polarization and position angle. I want to have it's scatter plot in Ra vs Dec plane and superimpose a galactic parallel on it. How to plot the ...
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Does RA/Dec vary with the Earth's orbit around the Sun?
I think the RA and Dec of a celestial object should change (ever so slightly) with the Earth's position in its orbit. So do we ignore this in general?
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Right ascension and declination visible at that local time and location
If I know the local time of an observer and her/his latitude and longitude, how can I know which stars are visible?
I'm developing a planetarium software using the Hipparcos Catalogue. I have also ...
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Figuring out camera pitch and roll given RA and DEC of center of image, as well as lat,long of camera and time taken
What I am trying to figure out is how to get the camera pitch and roll, as described in this image (the green yaw line is where the camera sensor is pointing
if given a RA, DEC (of center of image,ie ...
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Why isn't Amplitude the same as Declination?
From the way I understand Amplitude and Declination, it seems to me that they should always be the same, yet they are not, why?
P.S. In the picture I am imagining that the declination remains constant ...
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