Skyfield

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* Bugfix: minor planets and comets in Skyfield 1.44 would raise an
exception if asked for a position in the half of their orbit where
they are inbound towards their perihelion.

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

* Skyfield’s internal table for the ∆T Earth orientation parameter has
been updated, so that instead of including measurements only through
December 2021 it now knows Earth orientation through September 2022.

* Distance and velocity objects can now be created by calling their unit
names as constructors, like ``d = Distance.km(5.0)`` and
``v = Velocity.km_per_s(0.343)``.

* Updated the URL from which the Hipparcos database ``hip_main.dat`` is
downloaded, following a change in the domain for the University of
Strasbourg from ``u-strasbg.fr`` to ``unistra.fr``.

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

* An attempt at overly clever scripting resulted in a Skyfield 1.43
release without a ``setup.py`` in its ``.tar.gz``; within an hour, a
Python 2.7 user had reported that Skyfield could no longer install.
This release is identical to 1.43 but (hopefully) installs correctly
for everyone!

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

* Fixed :func:`~skyfield.magnitudelib.planetary_magnitude()` so it works
for Saturn even when the time is an array rather than a single time;
also, improved its calculation slightly with respect to Uranus.
`739 <https://github.com/skyfielders/python-skyfield/issues/739>`_

* Improved :func:`~skyfield.data.mpc.load_comets_dataframe()` so that
parsing ``CometEls.txt`` with the most recent version of Pandas
doesn’t stumble over the commas in the final field of (for example)
Halley’s Comet and give the error ``ParserError: Error tokenizing
data. C error: Expected 12 fields…saw 13``.
`707 <https://github.com/skyfielders/python-skyfield/issues/707>`_

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

* Added two new position methods
:meth:`~skyfield.positionlib.ICRF.phase_angle()`
and
:meth:`~skyfield.positionlib.ICRF.fraction_illuminated()`
that, given an illuminator (usually the Sun) as their argument,
compute whether the observer is looking at the bright side or the dark
side of the target body.
They replace a pair of old functions in the almanac module.

* The almanac routine :func:`~skyfield.almanac.moon_nodes()` would
sometimes skip nodes that were closer together than 14.0 days. It has
been tightened down and should now detect all lunar nodes.
`662 <https://github.com/skyfielders/python-skyfield/issues/662>`_

* Time objects now feature a :meth:`~skyfield.timelib.Time.to_astropy`
method.

* The position method :meth:`~skyfield.positionlib.ICRF.to_skycoord` now
sets the ``frame`` attribute of the sky coordinate it returns, and for
now only supports barycentric and geocentric positions.
`577 <https://github.com/skyfielders/python-skyfield/issues/577>`_

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

* Times now support arithmetic: you can add or subtract from a time
either a number representing days of Terrestrial Time (TT) or a Python
``timedelta`` which Skyfield interprets as TT days and seconds.
`568 <https://github.com/skyfielders/python-skyfield/issues/568>`_

* Fixed the ``.itrs_xyz`` vector of the geographic position returned
by the :meth:`~skyfield.toposlib.Geoid.subpoint_of()` method.
`673 <https://github.com/skyfielders/python-skyfield/issues/673>`_

* Skyfield now uses HTTPS instead of FTP to download JPL ephemeris files
like ``de421.bsp``. This does risk raising an error for users whose
machines have out-of-date root certificates. But it protects the
connection from outside tampering, and will keep working if the
``ssd.jpl.nasa.gov`` FTP service is ever shut down — as happened
earlier this year to FTP on NASA’s ``cddis.nasa.gov`` server.
`666 <https://github.com/skyfielders/python-skyfield/issues/666>`_