by Anne Holt Sunrise 1st: 06.41 30th: 05.35 Sunset 1st: 19.45 30th: 20.37 Astronomical darkness 1st: 21.51 to 04.33 30th: 23.24 to 02.47 Day length 1st: 13.03.35 30th: 15.02.04 Full Moon: 8th at 03.35 (363511 km). New Moon: 23rd at 03.27 (403817 km) Lunar perigee: 7th at 19.10 (356908 km) Lunar apogee: 20th at 20 02 (406461 km) April's
full Moon is known as the Pink Moon because of the pink flowers which
bloom at this time. Other names are the Sprouting Grass Moon, the Fish
Moon, the Hare Moon, and the Old English/Anglo Saxon Egg Moon or Paschal
Moon. This is the full Moon which is used to calculate the date of
Easter. We
actually have some highlights this month - for those who have a dark
garden to observe from. Having to stay at home is not so good for those
of us who have a street light outside the front garden and neighbours
at the back who seem to leave their lights on all night. Venus
is still dominating the evening sky, reaching its brightest on 28th.
Jupiter, Mars and Saturn are all low in the SE in the morning, though
only Jupiter is bright enough to really stand out. This
month's full Moon is is the biggest Supermoon of the year, occurring
just under eight and a half hours after the year's closest perigee, and
at last we have a promising meteor shower. A newly discovered comet is
brightening nicely and may become a naked eye object by month end. We
have Easter Sunday on 12th. The astronomical connection is that it is
the Sunday after the first full Moon on or after the Vernal Equinox,
which is taken as 21st March even when, as this year, it actually falls
on 20th. In case anyone is interested, the earliest date
for Easter Sunday is March 22nd. This is very rare - the last time was
in 1818, the next won't be until 2285. The latest date, April
23rd, is more common, some people alive now might just manage to see
one or 2 of these - last was in 1943, next in 2038. And the
sequence is not totally random: it begins to repeat itself after
5,700,000 years. If we still used the Julian calendar it would repeat
after only 532 years! Finally, April sees the 50th
anniversary of the Apollo 13 mission, when a near tragedy became what
many people consider to be NASA's greatest triumph. It lifted off on
11th, at 13.13 local time - and we all know what happened 2 days later.
Constellations Now that BST has been forced upon us, we have to wait even longer for the skies to darken each evening. By the time it gets really dark the winter constellations, including the beautiful area around the Winter Hexagon, so rich in bright stars, is sinking slowly in the West. Ursa Major is now high in the sky with the Plough overhead around midnight in the second half of the month. Follow the curve of the handle down to the orange coloured Arcturus, brightest star in the constellation Bootes the herdsman, and the 4th brightest in the night sky. The signature constellation of spring, Leo, is still riding high in the south and the Summer Triangle of Vega (in Lyra), Deneb (Cygnus) and Altair (Aquila) is now rising in the east and visible in the early hours. Planets Mercury: in Aquarius, mag 0.00 A
morning object but too low for observation. On 1st it rises at 06.16
but is still below the horizon when the sky begins to brighten. Its
position gets even worse during the month, it moves into Pisces on 10th,
when it is at mag -0.2, and Aries on 29th, at mag -1.5. On 30th it
rises at 05.32 but appears only 5 degrees from the Sun. Venus: in Taurus, mag -4.4 So
bright that it can easily be seen through the window of a lighted room -
assuming that it faces west. On 1st it is at 36 degrees soon after
20.00 and during the first few days of the month it passes south of the
Pleiades. It continues to brighten, reaching mag -4.5 by 10th, when it
is slightly lower, 28 degrees at around 21.00. On 26th the 3 day Moon
passes south of the planet, closest, 6 degrees, at 16.23. It reaches
maximum brightness on 28th, when it is at mag -4.52, a little short of
the maximum possible of -4.7. On 30th, only marginally fainter, it sets
at 00.52. Mars: in Capricorn, mag 0.8 Very
low in the morning sky, rises about 2 hours before the Sun throughout
April and doesn't get higher than 7 degrees above the horizon as the sky
brightens. On 1st it rises at 04.41. On 16th the Moon passes south of
the planet, separated by 3 degrees at 5am. On 30th it rises at 03.37
and has brightened to mag 0.4. Jupiter: in Sagittarius, mag -2.2 Another
morning object, much easier to see as it is slightly higher and much
brighter than Mars. On 1st it rises at 04.16 and should reach 11 degrees
in the SE before the sky begins to brighten a couple of hours later.
On 15th the 21 day Moon passes south of Jupiter, closest at 00.05 when
they are below the horizon. At 5am the Moon is between Jupiter and
Saturn, with Jupiter 4 degrees NW of the Moon, Saturn 4 degrees NE. On
30th Jupiter rises at 02.30 and should be easily visiible from around
03.50,slightly brighter at mag -2.4. Saturn: in Capricorn, mag 0.7 The
third major planet currently low in the morning sky. On 1st it rises
at 04.34 and only reaches 8 degrees in the SE by dawn. It improves
slightly during April, on 15th when the Moon passes south of the planet,
it will be at about 11 degrees as the sky brightens. The pair are
closest, 2 degrees 27', in daylight at 10.18. On 30th it rises at 02.43,
slightly brighter at mag 0.6, but still only gets to 11 degrees while
the sky is reasonably dark. Uranus: in Aries, mag 5.9 Not
visible this month. On 1st it is only 6 degrees above the horizon at
dusk. Its apparent separation from the Sun decreases still further
during the month as it approaches solar conjunction on 26th, only 26' at
its closest. On 30th it rises at 05.35, just a couple of minutes
before the Sun, and is separated from it by just 2 degrees. Neptune: in Aquarius, mag 8.0 Still
too close to the Sun to be visible. On 1st it rises at 06.15 but is
still 9 degrees below the horizon at dawn. On 30th it rises at 04.23,
more than an hour before sunrise, but still fails to get above the
horizon before the sky begins to brighten. Dwarf Planets Ceres: in Capricorn, mag 9.3 The
closest of the 5 dwarf planets, the only one which orbits in the
Asteroid Belt, is still too low for telescopic viewing or imaging. It
moves into Aquarius on 9th and by month end rises a couple of hours
before the Sun but is still very low in the brightening sky. Pluto: in Sagittarius, mag 15.1 Still too low to be succesfully imaged which, because it moves so slowly round the sky, it will be for many years yet. Haumea,
in Bootes at mag 17.3, and Makemeke, in Coma Berenices at mag 17.2 are
much higher, therefore better targets for the most experienced
astrophotographers. Because their orbits are very inclined to the
ecliptic (28 degrees and 29 degrees respectively) these can be found
quite far from the ecliptic. Haumea reaches opposition on 16th, when it
will be 52 degrees above the southern horizon at 01.52. Makemake
culminates slightly higher, 60 degrees, throughout the month. Both will
be high in the sky for much of the night. Eris: in Cetus, mag 18.8 The
most distant of the 5 officially recognised dwarf planets, the largest known solar system
object which has never been visited by a spacecraft, appears too close
to the Sun this month. Asteroid 3 Juno, the
third to be discovered but only the 13th in order of size, reaches
opposition on 3rd. It's in Virgo, mag 9.7. On this night it culminates
at 01.26, at 38 degrees in the South. Comets C/2019 Y4 (ATLAS) in Camelopardalis, mag 8.7. Discovered
in December 2019, this one is looking very promising. It has been
brightening rapidly recently and is predicted to reach naked eye
brightness by late April. It is a long period comet with a similar
orbit to the Great Comet of 1844 so it is thought that it could be
another fragment of the same parent body. Will it live up to its promise? Will it become another Great Comet? We can but hope. At
the moment it is circumpolar, close to the north celestial pole so
reasonably high in the sky throughout the night. If it continues to
brighten at the current rate it could end the month at mag 4.4. It
should be visible until late May when, if it behaves as predicted, could
have reached mag -3.7. Current estimates give the peak brightness as
-5.5. The bad news is that this is in early June, when it will be below
the horizon in darkness from our latitude. For anyone who
wants to try their luck at imaging it while it's still quite faint,
exact co-ordinates for each night are given in https://in-the-sky.org/ephemeris. C/2017 T2 (PANSTARRS) in Cassiopeia, mag 9.1 Again
circumpolar, so above the horizon all night. Moves into Camelopardalis
on 11th. This one is also predicted to brighten during April but
nowhere near as much - estimated mag for 30th is 8.9 C/2019 Y1 (ATLAS) Another
circumpolar one, but this is fading not brightening. It starts the
month in Andromeda at mag 9.0, then moves into Cassiopeia on 2nd. Not
as high in the sky as the others but still reasonably so for much of the
night. In Cepheus from 26th, when it will have faded, probably to
around mag 10.9. Finishes the month at mag 11.3. Recommended sites for exact positions, finder charts, and more information on all Solar System objects And for comet news Meteor Showers One reasonable shower this month. Lyrids,
active 14th to 30th (or maybe only till 25th - even the IMO doesn't
always agree with itself) ZHR 18, but usually also quite good on the
nights before and after the peak. The shower occasionally shows much
higher rates - in 1982 a ZHR of 90 was recorded, but nothing like that
is predicted for this year. It's likely that this shower was
very much stronger in the past, in 687AD Chinese astronomers reported
that meteors fell like rain. These are medium speed meteors, usually
without trails, but the shower could include some fireballs. They are
best seen in the early hours. The parent comet is C/1810 Thatcher, last seen in 1861, next return 2276. The good news is that the peak is just before New Moon, so no interference. Not much in the way of minor showers, at least not for those of us living in the northern hemisphere. The southern hemisphere has the pi Puppids, active 15th to 28th, peak 23rd, ZHR variable. Here, we may see a few meteors from the antehelion source, the radiant of which moves from SE Virgo into Libra during April. It
is also thought that there could be some activity in the early hours of
24th from the alpha Virginids. The radiant of these is far enough from
that of the ANT for it to be considered a separate shower. Parent body
is minor planet 2010 GE35. |
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