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# izubiaurre

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1. ## Solar Longitude to JD

Exactly. Thank you!
2. ## Solar Longitude to JD

If I'm understanding correctly what you've said, no. Solar Longitude is the position (angle, 0º-360º) in the elliptic orbit around the sun starting at the vernal equinox. Also, it differs in the number of days each range 0º-90º, 90º-180º, 180º-270º and 270º-360º. Wikipedia
3. ## Solar Longitude to JD

Hi, I'm trying to figure out if it's a way to calculate the date and time (JD) in a year for a solar longitude. I mean, I want to make a function that makes the calculations something like that: double SolarLongitudeToJD(int year, double solarLongitude) { // Here goes the code return JD; } I have searched in Jean Meeus book but found nothing about it (maybe it's the first time I haven't found any solution for my calculations in the book). I think that in the 24th chapter, there are the reverse calculation for what I trying to find: for a given date, various solar coordinates calculations, with the solar longitude between them. Thank you for advance.
4. ## Two rises in the same day. Calculation

Same happens here.
5. ## Two rises in the same day. Calculation

Thanks! Never heard of it before
6. ## Two rises in the same day. Calculation

Sometimes speaking and taking a little breath helps to get the results, even if they're not the expected ones. Thanks for everything. Now I have to test more deeply if this is a correct result by chance or if the algorithm is correct for every case.
7. ## Two rises in the same day. Calculation

Which library was that? I'm currently using AAplus for C#, but astro rising/setting functions are mine and I'm gettting nuts trying to find a solution fot this case. I'm getting these results: And this NO visible at 2019 Apr 21 is caused by the two risings in the same day 1st : 0:01 2nd: 23:57 The first one is before the nighttime of Apr 21th, so I'm calculating for the next day that gives 23:53, BUT the gap between Apr 21 0:01 and Apr 22 23:53 is more than 24h, my functions is returning wrong result. Maybe I should try to look this direction, if the gap between the results are bigger than 24h, treat as a special case.
8. ## Two rises in the same day. Calculation

Hi, I have a curious case that calculating some random astro rising and setting times, I was getting erroneus results that for certain day (only one in the whole year) this astro wasn't rising despite I know that was otherwise. After some debug with the results for every single day of the year calculating rising times, I realized that this wrong result was caused by the fact of having two rising times in the same day. The first one at 0:01 and the second one must be at 23:57 (I'm calculating 23:57 value following the results of the next days and previous days). I'm following the Astronomical Algorithms from Jean Meeus book formulas for calculations. I think that the algorithms from the book are not prepared for these cases. ¿Do you know any way to solve this problem? Thank you in advance
9. ## Stellarium - select star by galactic coordinates

Never thought of that. But, how I can do that? I mean, create some custom objects and put on selected coordinates for testing.
10. ## Sunrise/sunset duration

Thank you as always furrysocks2 for your response.
11. ## Sunrise/sunset duration

If I'm not wrong, the amount of sunlight is never equal to zero, even in the darkest of the night, there's a slight light in the sky coming across the atmosphere. The end of twilight is set by the elevation of the sun, that is -18º o 18º below horizon. Then, we have other sun's moments that are very apreciatted by photographers and film makers... Golden hour and blue hour. Golden hour is more or less from 6º to -4º. Blue hour from -4º to -6º. Twilight -6º to -18º. And belowe is night. So, I want something like for the duration or elevation range for sunrise/sunset.
12. ## Sunrise/sunset duration

Ok, but coul be taken the range between sun's upper limb touching the horizon and the bottom touching the horizon as sunrise?
13. ## Sunrise/sunset duration

Hi, I have a doubt about the duration of the sunrise/sunset. If sunrise is defined as a moment, is the moment when the sun is -0.8333º below horizon (upper limb appears on the horizon). But if we take as a duration, will be from this point to when lower limb touches the horizon? Which could be the sun's elevation at this moment? +0.8333º ? Or this value is related to other calculations? Thanks in advance
14. ## Stellarium - select star by galactic coordinates

I'm not using Stellarium as a telescope controller, only for calculations purposes. (using Stellarium 0.15.2 and all the stars DB downloaded). As you can see in the attached image, I've found a pretty close star to the point I was looking, but there's no name for the star, so I cannot get the proper motions and so on for my calculations. Even the other stars in the view have no name. Any idea how I can get the name for certain stars and the look in Symbad or another online star DB.
15. ## Stellarium - select star by galactic coordinates

Hi SoonyE, the telescope icon from the bottom isn't for changing the type of mount from equatorial to azimuthal and backwards?
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