Ewia is a tool to calculate the apparent sky position (i.e., azimuth and elevation) of astronomical objects such as stars or planets. It's an ancient project of mine (dates back to 2009) and was almost completely rewritten in 2017. It's quite easy to use:
usage: ewia [-h] [--json] [-c filename] [--no-system-catalog] -l location
[-t timestamp] [-z tzone]
object [object ...]
positional arguments:
object Object under observation. Must refer to the catalog.
optional arguments:
-h, --help show this help message and exit
--json Output data in JSON format.
-c filename, --user-catalog filename
Specifies user catalogs to read after system catalogs
have been read.
--no-system-catalog Do not read system catalogs (by default,
~/.config/ewia/catalog.json and ./.catalog.json are
tried)
-l location, --observer-location location
Observer location on earth. Can be either a reference
to the catalog or actual coordinates.
-t timestamp, --observation-time timestamp
Time at which the observation is conducted. Accepts
the special argument 'now', which reflects the current
time. Otherwise, must be in format YYYY-mm-dd
HH:MM:SS.
-z tzone, --observation-timezone tzone
When a timestamp is given, this parameter influences
at which timezone the timestamp is interpreted to be
in. Can either be a timezone definition such as
'Europe/Berlin' or a static timezone such as 'utc' or
'Etc/GMT+8'. Alternatively, can be set to 'auto' in
order to take the timezone that has been specified in
the catalog for the observing location. Defaults to
auto.
Catalogs are given in JSON format and an example is included in the .catalog.json file. You can easily dump positions of objects:
$ ./ewia -l Böblingen Saturn
Observer location: Böblingen (N48°41′16″, E9°0′17″), at time 2017-08-16 22:40:42 (Europe/Berlin)
Saturn: Altitude 16.1°, Azimuth 203.4° (SSW)
...or more objects at once...
$ ./ewia -l Böblingen Saturn Jupiter Venus Mars "Helix Nebula"
Observer location: Böblingen (N48°41′16″, E9°0′17″), at time 2017-08-16 22:41:18 (Europe/Berlin)
Saturn: Altitude 16.1°, Azimuth 203.6° (SSW)
Jupiter: Altitude -2.5°, Azimuth 263.0° (W)
Venus: Altitude -19.6°, Azimuth 354.7° (N)
Mars: Altitude -17.4°, Azimuth 324.6° (NW)
Helix Nebula: Altitude 6.2°, Azimuth 131.7° (SE)
and also of course dump everything as JSON:
$ ./ewia -l Bamberg --json M17
{'observer': {'lat': 49.884559, 'lon': 10.888149, 'tz': 'Europe/Berlin'},
'timezone': 'Europe/Berlin', 'timestamps': [{'timet': 1535186887, 'ts_utc':
'2018-08-25 08:48:07', 'ts_local': '2018-08-25 10:48:07'}], 'observations':
[{'obj_name': 'M17', 'positions': [{'apparent': {'altitide': {'deg':
-52.158318500088335, 'pretty': '-52°9′30″'}, 'azimuth': {'deg':
34.639970963487116, 'pretty': '+34°38′24″'}}, 'equatorial': {'ra': {'hrs':
18.346666666666668, 'deg': 275.2, 'pretty': '18:20:48'}, 'dec': {'deg':
-16.183333333333334, 'pretty': '-16°11′0″'}}}]}]}
It can also calculate the position of the sun:
./ewia -l Böblingen Sol
Observer location: Böblingen (N48°41′16″, E9°0′17″), at time 2018-08-25 10:48:43 (Europe/Berlin)
Sol: Altitude 39.9°, Azimuth 125.7° (SE)
Ewia was written by Johannes Bauer JohannesBauer@gmx.de and is released under the terms of the GNU General Public License v2 (included in the LICENSE file).