‘Journey through New Zealand’s skies‘ is also featured on The Jodcast, a volunteer podcast about astronomy set up by astronomers based at the University of Manchester’s Jodrell Bank but aims to cover astronomy carried out all over the Earth and beyond in collaboration with Space Place at Carter Observatory in Wellington New Zealand.
If you wish to find out more about the current week in space, I write a weekly column for Space Place. Find out here what’s in the sky this week.
Welcome to November, my favourite month of the year. The name November comes from Latin, meaning the ninth. In ancient times, it was the ninth month from the beginning of the year, in March.
Three Royal Stars are in the sky of November, and here in Wellington New Zealand we are looking at a Māori asterism called Te Waka O Tama Rereti (or Tamarereti), which is the great canoe that placed the stars in the sky. We are also talking about the circumpolar stars, the Magellanic Clouds and latest research results revealing they collided in the not so distance past, which resulted in a MiniMe Magellanic Cloud hurrying behind one of them. Fomalhaut is my favourite star this month, the loneliest star in the sky as it’s called and the Pleiades are back in the east just in time for Halloween.
Looking towards the southern horizon you should be able to see these asterisms on
- October 15 just before midnight NZDT,
- November 1st at 10:30 PM NZDT
- November 15 at 9:30 PM NZDT
- December 1st at 8:30 PM NZDT
Three Royal Stars hang across the evening sky of November: Aldebaran in Taurus, Fomalhaut in Piscis Austrinus and Antares in Scorpius. According to French astronomer Camille Flammarion, the royal stars were the ancient guardians of the sky in ancient Persia. It is believed that the sky was divided into four districts each guarded by one of the four Royal Stars.
Fomalhaut and the Lonely Fish
My favourite Royal Star has always been Fomalhaut (Haftorang/Hastorang) the Watcher of South. Back in the Northern Hemisphere, Fomalhaut was the southernmost significant star that I could see and we would always look at it as the secret pointer to the South. The rumours were not far off as Fomalhaut, Achernar and Canopus are almost in a straight line and if you can find Achernar you can always find South easily. The home-constellation of Fomalhaut is Piscis Austrinus, south of Capricornus and Aquarius, which is maybe why one of its names was Piscis Capricorni (Goat’s horn fish). Another name is Piscis Solitarius – the lonely fish. Though here in New Zealand we do have The Chocolate Fish that also comes wrapped individually, I wish we could just rename the constellation to that, for obvious reasons. And just saying, if you never had chocolate fish from New Zealand you never lived!
The lonely fish drinks all the water from Aquarius’s stream, says Richard Allen quoting the poets Virgilius and Ovidius who wrote that in their verses a few thousand years ago. Allen also mentions a translation inscripted in an 1340 manuscript almanach naming the constellation ‘Os Piscis Meridiani’, where meridional means southern of course, so just another synonym of Austrinus. According to Ian Ridpath, Eratosthenes called this the Great Fish and said that it was the parent of the two smaller fish of the zodiacal constellation Pisces (also known as “The Fish”).
Te Waka O Tama Rereti (or Tamarereti)
Back to the Eastern Sky, this time of the year, the Pleiades are visible again on the horizon. Harbingers for Halloween in the northern hemisphere where now skies are grey and ravens await for the first snows, for Māori, the Pleiades are now harbingers of summer. Together with the Hyades they make the wake and feathers from the Great Canoe (Waka) of Tama Rereti. November is the month when Milky Way surrounds the horizon like an ocean and the Great Waka was used by Māori to mark the arrival of the warm season when it was safe to travel the ocean. Tama Rereti’s Waka placed the stars in the sky and now lies moored in the wake of the Milky Way. Scorpius is Tauihu, the prow, floating low on the western horizon. Due south sits Te Punga, the anchor (the Southern Cross), with its rope, Te Taura, which is represented by the Pointers (Beta and Alpha Centauri). The latter is actually a multiple star system that holds our closest solar neighbour, the red dwarf Proxima Centauri, at 4.25 light years from Earth. The sails of Tama Rereti’s canoe are Achernar and the beautiful southern dwarf galaxies the Small and Large Magellanic Clouds (SMC and LMC). Canopus/Atutahi is the paramount chief of the skies at vigil in the waka. A source of X-rays and the most luminous close star at 310 light years from the Sun, Canopus is used for navigation by all spacecraft that employ star tracker devices, which determine the orientation (or attitude) of the spacecraft with respect to that star. Te Taurapa, or the stern of the waka is in the Eastern Sky, formed by Orion.
Here is the Māori story of Tama Rereti.
In New Zealand we can see both Scorpius and Orion in the sky in the same time and this is the time of the year to do it.
Circumpolar objects – the Magellanic Clouds
With the Milky Way laying across the horizon, there aren’t so many deep sky objects handy to observe. However, we are in the Southern Hemisphere and the spectacular Magellanic Clouds (or Nubeculae Magellani) are high in the sky at this time of the year. Remember they were the sail of the waka o Tama Rereti and this sail is now set. In my first night here in New Zealand, I printed a map of them and started looking onto the southern sky annoyed by a cirrus cloud I thought, only to discover to my delight that it was the Large Magellanic Cloud I was looking at. It is that spectacular and substantial. The large Magellanic Cloud is about 160,000 light years from us and the Small Magellanic Cloud is about 200,000 light years away. To find them, draw a line from the southern cross to Achernar. Two thirds from the southern cross on each side of the line are the two galaxies. Now far apart, it seems that the Magellanic Clouds collided in the past, as a paper just published in October 2018 in the Astrophysical Journal Letters supports that idea with data from the Gaia satellite.
Inside the Magellanic Clouds are amazing deep sky objects.
The Large Magellanic Cloud was host galaxy to a supernova (SN 1987A), the brightest observed in over four centuries, co discovered independently by Ian Shelton and Oscar Duhalde at the Las Campanas Observatory in Chile on February 24, 1987, and within the same 24 hours by the legendary Albert Jones in New Zealand. Albert Jones was the first astronomer in the world that made 500,000 observations and he could distinguish about one twentieth of a magnitude, whereas most people can distinguish about one tenth of magnitude changes.
The Large Magellanic Cloud is home of Tarantula Nebula that gets its name from its resemblance to a huge spider. Tarantula Nebula is very luminous, so great that if it were as close to Earth as the Orion Nebula, the Tarantula Nebula would cast visible shadows. In fact it is the most active starburst region known in the Local Group of galaxies.
The Small Magellanic Cloud is on the other side of the imaginary line that goes from Achernar to the Southern cross. Recent research suggest a giant piece broke off the Small Magellanic Cloud in South-Eastern part of the galaxy, which goes toward the Large Magellanic Cloud at a speed of 64 kilometers per second and that the Small Magellanic Cloud may in fact be split in two, with a smaller section of this galaxy being behind the main part of the SMC (as seen from Earth’s perspective), and separated by about 30,000 light years. The reason for this might be due to a past interaction with the LMC splitting the SMC, and it is believed now that the two sections are still moving apart. The smaller remnant of the Small Magellanic Cloud is now called the Mini Magellanic Cloud, a MiniMe of a galaxy.
About 15 times closer than the Small Magellanic Cloud but on the same line of sight is my favourite star cluster 47 Tucanae, the most beautiful globular cluster, rival of Omega Centauri.
The Void from the North
Really once you’ve seen the galactic centre at zenith and the southern circumpolar objects, the northern sky seems a bit devoid of stars. Still, having said that, to the North, the great horse of Pegasus is flying through the sky. Andromeda is in the sky too and if we could only see it from Wellington…, but even if we did it would be like a smidgen, since is very close to the horizon.
All the stars that we touched briefly on, will come back in a year’s time in the same formation. We cannot really perceive the proper motion of the stars, it takes them thousands of years to visibly shift positions (well maybe except Barnards’ Star). So we are now looking at the same constellations as our ancestors did thousands of years ago (maybe 3 or 4,000 years ago). That’s the reason why the stars were used to mark seasons and navigate, their patterns remain constant for thousands of years. What changes the sky and makes every year different are mostly the planets, and sometimes other visitors like comets or asteroids.
What’s NOT in the sky
First of all, from Wellington New Zealand we cannot see the northern circumpolar stars. These are the stars that make the Big and Small Dipper, Polaris (which is opposite to the South Celestial Pole) and Casiopeea, which is on the other side of the Milky Way, kind of opposite the Southern Cross.
On the Zodiacal band, the Sun is in Libra from October 30 to November 23 then in Scorpius from November 23 to November 29 and finally in Ophiuchus from November 29 to December 17 (Ophiuchus is not included in the Zodiac).
For the reasons of looking straight into the Sun we predict that the above-mentioned constellations will not be visible after sunset during November even if you try really hard.
If you look on the opposite side to the setting Sun, Taurus should be rising and further dominating the night sky.
This is the Zodiacal band, an awesome drawing by Eugene Georgiades but he names Scorpius Scorpio. What can I say? Eugene… Scorpius, Scorpius, Scorpius, Scorpius!
November 2018, on the planetary realm,
At the beginning of the month Jupiter and Mercury will be low in the west at dusk, setting toward the southwest 1½ hours after the sun. Orange Mars is in Capricornus north of overhead at dusk. Midway between Mars and Jupiter is Saturn in Sagittarius.Jupiter sets earlier each night as we move to the far side of the sun from it. By mid-month it is lost in the twilight. Mercury holds its position in the west before disappearing late in November when it passes between us and the sun. A thin crescent moon will be near Mercury and Jupiter on the 9th. At the end of the month Saturn and Mars are the only naked-eye planets in the evening sky. The moon will be near Saturn on the 11th and 12th and close to Mars on the 16th. Venus rises a little south of east 50 minutes before the sun at the beginning of the month; more than 1½ hours before sunrise at the end. It is a long thin crescent in a telescope and big binoculars.
The month starts with the Moon at Last Quarter, then New Moon is on the 8th, followed by First Quarter on 16 November and full Moon on the 23rd.
And with this, I wish you a great November and clear skies from Space Place at Carter Observatory in Wellington New Zealand. `