<p>In the answer <a href="https://physics.stackexchange.com/a/26787">https://physics.stackexchange.com/a/26787</a> you can find an example how to convert celestial coordinates to horizon coordinates an than check, if the altitude is above the horizon </p>

CC BY-SA 3.0
2014-07-01T07:48:50.090Z
Thank you for pointing me in the right direction. I'm probably going to use PyEphem for this
Michal Holub
CC BY-SA 3.0
2014-07-10T10:17:15.337Z
I did and it worked great. One comment for future followers - if you're crosschecking alt/az with Stellarium (for example), don't forget that pyephem works in UTC timezone by default while Stellarium uses yours....too me a few hours to realize this
Michal Holub
CC BY-SA 3.0
2014-06-30T17:17:06.197Z
2014-06-30T17:17:06.197Z
2017-04-13T12:40:15.377Z
samcarter_is_at_topanswers.xyz
<p>I have a HYG catalogue and I'd like to filter out stars visible at night and in Europe. </p>

<p>Doesn't have to be exact. I was assuming that it'll be all stars with positive declination, but I wasn't sure about RA values.</p>

<p>Thanks, Michal</p>

<star>
Naive star filter visible at night in certain country
Michal Holub
# Naive star filter visible at night in certain country

(Asked by: username_0 on 2014-06-30)

I have a HYG catalogue and I'd like to filter out stars visible at night and in Europe.

Doesn't have to be exact. I was assuming that it'll be all stars with positive declination, but I wasn't sure about RA values.

Thanks, Michal

**Tags:** star

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## 1 answers

### Answer by username_1 on 2014-06-30. Score: 1 | Accepted answer

In the answer <https://physics.stackexchange.com/a/26787> you can find an example how to convert celestial coordinates to horizon coordinates an than check, if the altitude is above the horizon

> **Comments:**
> **username_0**: Thank you for pointing me in the right direction. I'm probably going to use PyEphem for this  
> **username_0**: I did and it worked great. One comment for future followers - if you're crosschecking alt/az with Stellarium (for example), don't forget that pyephem works in UTC timezone by default while Stellarium uses yours....too me a few hours to realize this  

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