April

As declared by the Astronomers Without Borders (AWB), April is the Global Astronomy Month (GAM). But wait, it gets even better than that! Also in April, an entire week is dedicated to the International Dark Sky Week! April is full of stars. 

Look for brights stars in the evening sky and for the Galactic Centre, which is now rising in the east anytime between midnight at the beginning of the month and 10PM at the end of the month.

If you are on the hunt for meteor showers, you can check them all out in here: List of Meteor Showers. The Lyrids, Pi-Puppids and Eta Aquariids in Lyra (low on the horizon from Wellington and Wairarapa), Puppis and Aquarius (visible early in the morning in the east) are the listed meteor showers occurring around April.

Check out the Milky Way in April, it looks amazing as it stretches almost horizon to horizon. As the dense star fields and dust lanes of the Galactic Centre become more visible, our galaxy creates quite a spectacle this month. Those of you with a keen eye will be able to spot the dark silhouette of the Milky Way Kiwi rising in the early morning at the start of the month.

And join us for the Galaxy hunting season, which is opening now with amazing objects in Leo and Virgo coming into our viewfinders.

A bit about April

Is autumn again in New Zealand, the grapes have been harvested, awaiting to be transmuted into wine and while we wait, we finally can enjoy long beautiful nights in which the galactic centre climbs to the Zenith.

On the other hemisphere, however, is spring. April’s etymology points to springtime. A Latin name — mensis Aprilis (the month of April), has the same root as aperire meaning “to open”(Dictionary.com) — a reference to the opening or blossoming of flowers and trees, which is a common occurrence throughout the month of April in the Northern Hemisphere . April could also be the mispronounced name of the Greek goddess Aphrodite (Etimonline)

The origin of the names used today for the months of the year in English and Latin countries go as far as Ancient Rome and Greece. Knowing the geographical location of the places where these legends and names come from, and looking at weather patterns in those place at the time they were institutionalised, can provide meaning to many of the ancient myths and names that we inherited. For instance, March is the month of Mars, the god of war. Could it be because in March, in the temperate zones of Europe, war is waging between the snow and the plants coming back to life again? March is notorious for its late snowfall that freeze and damage the fragile plants that just came back to life. April is the month when Nature is putting up a spectacle in these temperate zones of the Northern Hemisphere. Imagine most flowers blooming at once — that’s how beautiful April is. Who could it be a better patron for this month, then Aphrodite – Venus, the goddess of love and beauty?

Night on Venus in Infrared from Orbiting Akatsuki  Image Credit & Copyright: ISAS, JAXA

In ancient Rome the first of April was dedicated to Venus and the celebration of Veneralia observed. Little did they know about the hellish world Venus is.

Can you spot Venus in the night sky this year? Follow this link to see where it is and if you can see it.

In the meantime, Zeelandia might get the first taste of winter as the odd southerly front roars up from the Southern Ocean to remind everyone what’s on the way. Not always a bad omen, the roaring southerly fronts also remind us of the super clear, cool and stable air that often sits behind those fronts and makes for cool evenings of amazing seeing. Those closer to the tropics start seeing a bit less humidity as the dry season starts.

What’s the Sun up to?

From Wellington, the Sun rises at about 7:36AM at the beginning of the month and sets around 7:12PM and rises at about 7:07AM and sets about 5:28PM on the 30th of April. Yes that is correct – in April daylight saving ends. Towards the end of the month beautiful and long nights await.

In April, the Sun transits first the zodiacal constellations of the fish, Pisces, and later, after 20th of April, the Ram, Aries. And it doesn’t matter which side of the world you are, in the case of the zodiacal constellations, we can observe them in both hemispheres, however, here in the south are upside-down to what we know in the north. That throws Orion’s legs in the air. In this hemisphere night sky he’s always performing a cartwheel – albeit slowly, through the night. Orion is not a zodiacal constellation but is neighbouring them and also marks the edge of our galaxy. Zodiacal constellations are stars that are visible behind the plane of our solar system, and form a band in the sky, called the Zodiacal Band. What’s a constellation?

Zodiacal predictions

Since the Sun is transiting both the space we call Pisces and Aries it means we cannot see the stars in these constellations, behind the Sun they are washed out by it besides it’s dangerous to look into the Sun. Of course, if you have solar telescope, that is well maintained and is designed for looking at the Sun, then you can look at the Sun.

The Sun in Aries means only one thing: opposite the Sun (that 180 degrees on the other side of the zodiacal band) is Scorpius. This means, Scorpius will be visible all night long! Scorpius is quite high in the late evening by the end of the month – meaning that Sagittarius and the galactic centre is also following.

You are not who you think you are ...
This is the Zodiacal band, an awesome drawing by Eugene Georgiades. The position of the Sun as it transits the Zodiacal constellations is different than what it was 1000 years ago so the newspaper Western zodiacal signs are out of sync with the real position of the Sun with about half a month.

The Milky Way

…the most spectacular feature of the Southern Hemisphere’s sky … and to say this is such an understatement… The Milky Way is so striking here in New Zealand, that in the absence of a polar star, we tell everyone that we can and should find directions by it.

River versus Octopus’ arm

Milky Way has many names but most of them indicate something like a river in the sky. The reason for it being likened to a river is because in the Northern Hemisphere, our Galaxy looks like one. There, when the galaxy is at its highest in the sky, the constellation of Cygnus — which marks its edge, climbs at Zenith. Because we look towards the edge of the Milky Way, we see less stars. Likened to a river, or a band of stars stretching through the sky like a road that has equal dimensions throughout – via lactea (Milky Way in Latin). From New Zealand, in April, the Milky Way looks like one of the arms of an octopus. The centre of The Galaxy and with it the fat galactic bulge is slowly rising on the eastern horizon and its thin edge it setting on the western horizon. From the rising core, all the way to its setting edge — from Scorpius to Taurus all is one glorious panorama.

The octopus is a very special symbol here in New Zealand, as it is said that one of them, Te Feke o Muturangi, was the reason why some explorers ended up in Aotearoa – they followed it here.

You can see the Milky Way galaxy stretching across the sky in April, with the galactic bulge rising in the south-east. Map created with Carte du Ciel.

To find directions, just follow the Milky Way. Where is starting to thicken, you will find the Southern Cross. Then use the Southern Cross to find South.

Scorpius and Orion

Mortal enemies in ancient Greece, hence they’ve been placed in opposite parts of the sky – or at least that was their mnemonic, Scorpius and Orion look here like noting that would indicate they can symbolise a scorpion or a human.

At the antipodes, Scorpius looks like a scorpion, slithering around the horizon. Because of Earth’s tilt, the constellation only rises 30 degrees or so above the horizon. Just like a scorpion, the asterisms is crawling around the horizon from southeast to southwest and then disappears into Mother Earth again, like scorpions would do in the desert.

Sagittarius at the antipodes of New Zealand looks like a teapot.

Sagittarius the teapot and Scorpius the Scorpion in the Northern Hemisphere view.

In Aotearoa, the Māori name for Scorpius this time of the year is Manaia Ki Te Rangi – the guardian of the heavens – you can see why. The name we are accustomed to is Te Matau A Maui – the fishhook of Maui. It is often that Māori have a few names for the same stars in different configurations throughout the year, which are linked to indicating seasons.

Scorpius as Manaia Ki Te Rangi in April

Orion the hunter is upside down in our sky. Perhaps that’s why everyone’s calling it a pot here. Talking about calling names… But you can see why, the stars of Orion’s Belt and sword resemble to a pot that you put on a celestial stove.

So what can we see? – Ropes of Stars

A rope of stars is our romantic definition of Gould’s Belt. These are bright stars associated with star forming regions that exist in galaxies. This Belt includes Orion, Scorpius-Centaurus, Cepheus, Perseus and the Taurus-Auriga region. A January 2020 paper included the Gould Belt into a wave of interconnected stellar nurseries called the Radcliffe Wave.

Sky in April

It is a great time of the year to get the telescope out in the early evening, now that daylight saving has finished, and just browse the star fields, catching glimpses of nebulae and star clusters.

Bright stars on the Ecliptic

Through the northeastern sky runs the ecliptic, which marks the plane of our solar system, bearing the zodiacal constellations. These intersect the Milky Way in Scorpius and Sagittarius, which are either side of the centre of the Milky Way and Taurus and Gemini, which flank the edge. The ecliptic is “a great circle on the celestial sphere representing the Sun’s apparent path during the year, so called because lunar and solar eclipses can only occur when the moon crosses it.”

To see things on the ecliptic one should simply turn towards that part of the sky that carries the memory of the path of the Sun or of the Moon, for that matter.

From west to east these bright stars are:

Stars in the Milky Way

Outside of the Ecliptic are a bunch of other bright stars including the famous Betelgeuse, red giant and Rigel, a blue giant, both in Orion. Then the Dogs of the Celestial River, because they are guarding it each from one side of it, are yellowish- white Procyon – in the Small Dog 0.34 and Sirius – in the Big Dog. @-1.46. Sirius, a blue giant, is the brightest star in the sky. The big dog constellation finally looks the right way up heading also to the western horizon too. From it, turn your gaze left.

Nearby comes Canopus -0.72, the second brightest star in the sky. Canopus is not in the white band of the Milky Way. Standing tall, Canopus is high in the sky as it likes to be at this time of the year after sunset. Canopus is a circumpolar star from Wellington. Which means that it goes around in circles in 23 hours and 56 minutes, riding something that is like a pod on the celestial Ferris Wheel of the Southern Skies, a giant wheel that never stops, with the South Celestial Pole at the centre and a bunch of other stars that look like a circle.

Circumpolar objects to New Zealand

There are some stars that will always be in our skies. These are called circumpolar. From Wellington, they cover declinations from – 50 degrees to 90 although they would be too close to the horizon to be seen at -50 so more realistically you will see stars around -55, for instance Achernar is -57 and very bright.

Circumpolar stars rotate in 23 hours and 56 minutes thus they appear to be in different positions in the sky – so take that into account when you look for the Southern Cross.

 

This time of the year, the Southern Cross to Sirius region is great to observe. Find out here what’s in that region of the sky.

Binocular objects in April

have a look at our videos on how to find these objects:

Telescope Objects in April

nice and high

April 2020 in the sky

If you are stuck inside the house this April, we are bringing you the Universe. Also some space News and what’s going on in the world of space and astronomy. Come stargazing in our podcast as we look at the stars of April 2020!

by The Science Team