Skyfield

----------------------

* Upgraded to a new version of the ``sgp4`` Python library that, when
possible, uses the fast official C++ implementation of SGP4.

* Added a :meth:`~skyfield.sgp4lib.EarthSatellite.find_events()` Earth
satellite method that finds the times at which a satellite rises,
culminates, and sets.

* Improved the logic behind the :doc:`almanac` routines to avoid rare
situations in which a cluster of nearly identical times would be
produced for what should really be considered a single event.
`333 <https://github.com/skyfielders/python-skyfield/issues/333>`_

* Fixed the :meth:`~skyfield.timelib.Time.utc_strftime()` method so it
does not report that every day in all of recorded history is a Monday.
`335 <https://github.com/skyfielders/python-skyfield/issues/335>`_

-----------------------

* Added basic :doc:`planetary` support, enough to compute the position
of a given latitude and longitude on the surface of the Moon.
`79 <https://github.com/skyfielders/python-skyfield/issues/79>`_
`124 <https://github.com/skyfielders/python-skyfield/issues/124>`_
`258 <https://github.com/skyfielders/python-skyfield/issues/258>`_

* Added :func:`~skyfield.almanac.oppositions_conjunctions()` for finding
the dates when a planet is at opposition and conjunction with the sun.

* Added :func:`~skyfield.trigonometry.position_angle_of()` for computing
astronomical position angles.

-----------------------

* Changed the URL for the Hipparcos catalog, because the VizieR archives
FTP server is no longer responding.
`301 <https://github.com/skyfielders/python-skyfield/issues/301>`_

* Added a :func:`~skyfield.almanac.dark_twilight_day()` function that
not only handles sunrise and sunset but also all three kinds of
twilight.
`225 <https://github.com/skyfielders/python-skyfield/issues/225>`_

----------------------

* Changed the URL from which leap second files are downloaded; the
server that previously provided them is no longer responding.
Thanks to Richard Shaw for the pull request.
`296 <https://github.com/skyfielders/python-skyfield/issues/296>`_
`297 <https://github.com/skyfielders/python-skyfield/issues/297>`_

* Added a :func:`~skyfield.almanac.risings_and_settings()` function for
computing rising and setting times.
`271 <https://github.com/skyfielders/python-skyfield/issues/271>`_

----------------------

* Provided a constellation lookup routine through
:func:`~skyfield.api.load_constellation_map()`.

* Added a ``position_from_radec()`` function.

* Fixed the ``apparent()`` method in the case where a single observer
position is observing an entire vector of target positions.
`229 <https://github.com/skyfielders/python-skyfield/issues/229>`_

-----------------------

* Fix: an exception was being thrown when creating a ``Loader`` pointed
at a Windows directory for which Python’s ``os.makedirs()`` function
returned a spurious error.
`283 <https://github.com/skyfielders/python-skyfield/issues/283>`_

* The internal ``reverse_terra()`` routine can now be given an
``iterations=0`` argument if the caller wants geocentric latitude and
longitude.