First of all, the great announcement: There is a radio show coming (you may call it podcast too) on Wellington Access Radio. It is called “Wellington, the Centre of the Galaxy” and it’s meant to be a talk show about events that are happening in the sky… and what’s that got to do with us here on Earth… And what’s best, it’s got me in it! So, watch this space!
Why did we call it that? It’s got to do with the night sky in August when from Wellington, looking up (at night) we can gaze straight at the centre of the Galaxy. Providing that the sky is clear of course. And since we live here, of course Wellington is the centre of the Galaxy regardless what’s above our heads or not. And to be fair, it’s actually nice to know that our show name has some support from Above – in the most scientific way.
Back to the night sky, this is an astrophotographer-friendly blog, about what is in the night sky in August. In the Southern Hemisphere, yupee for winter, this is my favourite time of the year. I could totally exist just under the winter sky, even though I am normally found freezing in summertime as soon as a bit of a cloud covers the Sun. Somehow, once I lift my gaze up, all the cold disappears as if through magic.
Here’s why I like winter here so much:
- First of all, in winter evening comes really early, so by 17:00 it’s dark outside. It stays like that until morning time, about 7:00. So there are so many hours of night in which I can admire my favourite thing:
- The galactic centre. It goes here all the way up to Zenith.*
- (1) and (2) are true, providing there’s no Moon to light-pollute the night.
Moon status this month.
(When not to get too excited about deep sky photography).
Everybody knows how much I love the Moon (not) because it casts too much light for my taste. Even when you look at it with a telescope at night, unless you have a Moon filter, you can literally feel your eyeball, as the rhodopsin (as little as it gets) is instantly broken down – the equivalent of your mum turning the light on and dragging you out of bed while you’re fast asleep. So if the eye hurts that much, imagine how ‘impressed’ the ccd of your supersensitive astrophotography camera would be.
A good time to start doing deep sky astrophotography is, from experience, about the second day after the full Moon. So plan your shots accordingly. This month, that would occur around 10th of August, as the Full Moon is on the 8th of August. The Moon rises every day about 50 minutes later, in average. So the first night after Full Moon you have 50 minutes till the Moon comes up. In the same time, you need to wait for the sky to get dark enough, as just after sunset there is twilight first; by the time the twilight ends, the Moon might as well rise, so the second day after seems like a better idea. The second night you have 100 minutes from sunset till moonrise. The third night 150 minutes. And so on. And just point the camera away from it (that is from the rising Moon), and you should be fine even if it’s kinda starting showing up.
The month actually begins with a waxing gibbous Moon, following from First Quarter (which falls around 30th of July). A week into it, on the 8th, it’s changing into “Too Much Light At Night” Full Moon. Another week later, by the 15th, is the Last Quarter and finally the big white thing turns into new Moon on the 22nd when it’s not only new (invisible) but also black. From white to black in two weeks. Confused already?
What’s a black Moon?
Nobody really can tell and you can find out here what people believe it is but one thing is for sure, the black Moon of August 2017 will cause a total eclipse of the Sun. This particular Black Moon, says Timeanddate, is the 3rd New Moon in a season with 4 New Moons, which apparently is a rare combination.
How come there isn’t a solar eclipse every time there is a full Moon?
The Moon’s orbit is tilted about 5 degrees from that of Earth’s (5,15 to be more precise). If it weren’t we would have had a solar eclipse every New Moon (fun, fun, fun), and a lunar one every Full Moon for that matter, but no, it had to be tilted! So then only sometimes the Moon intersects the orbit of Earth at the exact time when there is a New Moon. This great video from the Exploratorium in San Francisco explains in detail how that is.
The total solar eclipse on the 21st of August (22nd – NZST)
I wish everyone could see a total solar eclipse at least once.
This month is exceptional as something spectacular finally happens also in the day-sky – a total eclipse of the Sun. Alas, it is only visible from the United States (lucky them). The eclipse will take place on their August 21, (our 22nd) 2017. For a short while, the Sun will disappear behind the Moon, the day will turn to dusk, silence and temperature will fall rapidly changing everything into an eerie and strange landscape, which I cannot compare to anything as it’s really one of those moments that marked my soul for life and it’s here to stay.
Because this eclipse streaks across the whole of the US they called it the Great American Total Solar Eclipse. It will darken skies all the way from Oregon to South Carolina, along a stretch of land about 113 kilometers wide. Make sure you wear your eclipse glasses if you want to check it out and only look at the Sun with protection. The thing about the eye is that it does not have receptors for pain and so even though the Sun burns the retina when gazing directly at it, the damage is painless, and unfortunately permanent.
What has Alex Conu got to say about this year’s solar eclipse
My good friend and sky colleague Alex Conu who has kindly provided these amazing shots, has already written a great blog where he discusses in detail how to photograph as solar eclipse. You can find there everything you need to know about it, what cameras /gear to use, exposure times, best places to be, not to mention duct tape (my favourite), Allen keys, and how to NEVER ever shot a solar eclipse with new gear. Alex has it all.
Those of us who cannot share the excitement and preparation for the solar eclipse, will have to stay behind at home and find other things to do, such as look at the night sky. Or go to work. Or learn thy stars! That’s the one time that I can think of when the moonlight is actually useful, when you start learning the constellations and all you need to see are the brightest stars.
The sky in NZ is mostly ridiculously dark and there are too many stars anyway so it takes the Moon to wash most stars out to be able to pinpoint the brightest!
Constellations of the evening sky in August
First of all, there are some constellations that will always be visible on a dark sky regardless of the season (from New Zealand), these are the circumpolar constellations. Depending at which latitude you are on Earth, you will be able to see more or less of them. For instance, from the poles you can only see one celestial hemisphere providing that the Sun is set. But at the equator this changes, there are no circumpolar constellations as the cardinal points of celestial north and south are straight on the horizon.
Then there are other constellations that are just behind of the ecliptic, the path of the Sun (and Moon) in the sky. These are the zodiacal constellations and represent humankind’s oldest sidereal (starry) calendar. Every month at sunset there is a new zodiacal constellation rising. They cycle through in 12 months. This month, the Sun is in Cancer and as it sets, on the opposite side you can see Capricornus rising. Just East of Capricornus is Aquila and above it Sagittarius, Ophiucus and Scorpius.
The third type of constellations are those that we cannot see from New Zealand, such as Cassiopeia or the Big Dipper or the Small Dipper and of course we cannot see the star called Polaris either. The Earth would have to be transparent for that to happen as it’s on the opposite side to the Celestial South Pole. I figured out that Cassiopeia is approximately 180 degrees to the Southern Cross – still inside the Milky Way. The remnants of the Northern Sky here in the south are this month Corona Borealis, Hercules, Lyra (with Vega), Cygnus, the Northern Cross (with my favourite star of all times Albireo on one side and Deneb on the other just grazing the horizon, you must not blink in order to see it). Deneb, Vega and Altair make the Northern Summer Triangle (summer, oh my**^**%$#$), we are all freezing in here, especially tonight was a really cold one. These are followed by Pegasus, the flying square horse, and Andromeda, which looks as if she’s throwing herself back into the Northern Hemisphere’s sky. Late in the predawn sky, Perseus’ feet, then M45 and Orion are the last to show up.
But … cold or not, in the evening sky, the Galactic Centre is at Zenith*! So, as I mentioned before, all you have to do from New Zealand (‘s latitude) is to lift up your gaze to look at it. And on a really dark night (that means no Moon please, thanks heaps), you may even be able to see the Milky Way Kiwi (MWK). MWK is not an imaginary thing that gives the name of this blog but also a dark patch that looks just like a Kiwi bird, one of the native birds of New Zealand, and a national icon for us. It also happens that it’s found near the galactic centre. It is truly remarkable how this kiwibird in the sky resembles to the one on Earth, and how funny it is that the first to see it were the NZ’ers – since they were the only ones to recognize such shape: the kiwibird is endemic to New Zealand (see my blog “please stop eating us” if you wish to hear more about kiwibirds). Biased as charged!
* This is extraordinary and unique. We might take it for granted here but we should not. In fact, New Zealand’s latitude is the only place where the centre of the Milky Way goes all the way up to Zenith. Europe and North African latitudes see it only rising at about 30 degrees above the horizon… and it’s upside down… it looks just like a colossal scorpion crawling around Earth’s edge … hence the name. Given by the other extraordinary navigators – through the sand dunes: the Arabs. I love this dichotomy between the sand, holding the memory of the sea, and this dry creature that is the Scorpion, and the waters of the Southern Hemisphere that imagine the ‘fishhook of Maui’ in Maori star lore. And from the zenith, the fishhook pulls the Milky Way down from the heavens. That’s how the ancient Maori explained the rotation of Earth.
Then, it takes an astronomer to recognise it but here is the truth (Frank Andrews told me it): we can see more stars in the Southern Hemisphere – because there are more stars at the centre of the Galaxy. So even though we see it centre in the Northern Hemisphere too, from mid-latitudes it’s half washed away by both the horizon and light pollution. Only here in this part of the world, it’s revealing itself in all its splendor across August’s night sky like a huge arch of silent, cold, and shimmering light. Since the Galaxy is so bright here, it’s easier to see its dark patches.
It is also interesting that the cultures who look at these dark patches are from those places near or below the equator: Inca, Aboriginal, Māori. And of course the latest Culture of Astrophotographers who actually invented the Milky Way Kiwi. Although to be fair, culture means something you do repetitively and in plain sight and it helps you and your offspring to survive. I’m not sure how to reconcile this with the hoards of people freezing to death (it gets very cold at night even in summer) and spending their life savings on gear that they only use at night to take snapshots of the sky. Although they seem to be multiplying, talking about survival… I think that could be because astrophotography is addictive.
Don’t tell me I din’t warn you!
Where to spot the Milky Way Kiwi
I have seen the MWK with my naked eye at Lake Tekapo. But again, I am in love with it so I know exactly what to look for. A really (really) dark sky is required for it so I would suggest that the best thing to do first is to start looking for it in long exposed pictures of the night sky.
The Milky Way Kiwi is in the Scorpius Sagittarius region, holding the centre of the galaxy on its head like a crown.
Binocular objects in August’s Night Sky.
I always said, if you don’t yet have a telescope you might as well forget about getting one until you learn your constellations and your binocular targets. It’s as much fun as deep sky photography. Starhopping is fun too. So learn those directions first and you will see they will come in handy later. Yes I know many telescopes now have goto equipment but nothing compares to the thrill of learning the sky in your head. So since the galactic centre is handy this month let’s abuse it for binocular objects:
The Milky Way is brightest and broadest overhead in Scorpius and Sagittarius. In a dark sky it can be traced down past the Pointers and Crux into the southwest. To the northeast it passes Altair, meeting the skyline right of Vega. The Milky Way is our edgewise view of the galaxy, The thick hub of the galaxy, 30000 light years away, is in Sagittarius. The actual centre is hidden by dust clouds in space. The nearer dust clouds appear as gaps and slots in the Milky Way. Binoculars show many clusters of stars and some glowing gas clouds in the Milky Way. Underneath Sagittarius and Scorpius is Ophiucus, the strange so called 13th zodiacal constellation. According to Karen W. Pierce who made an excellent list of binocular objects that you can find on this site http://astrogeek.com Ophiuchus is rich in Messier Objects. You can find M9, M10, M12, M14, M19, and M6, which provide examples of different concentrations of stars. Also IC 4665, a big but often overlooked open cluster located near Beta Ophiuchi. On a dark night it is visible to the naked eye.
Sagittarius contains more Messier objects than any other constellation. The best way to identify them is to take them one by one. The main stars of Sagittarius form the famous “Teapot” asterism, which here in Wellington looks upside down. It is said that for the Northlings, the brightest part of the Milky Way seems to emerge from the Teapot’s spout like a puff of steam. In Sagittarius, M22, the Great Sagittarius star cluster is a very large globular — the best of the constellation’s many globulars. At magnitude 5.1 it is an easy binocular object. M23, is another one of the many clusters in Sagittarius. M23 presents over 100 stars in an area about the size of the Moon. Lagoon Nebula – M8, visible with the naked eye in dark nights, just north of the richest part of the Sagittarius Milky Way. Triffid Nebula – M20, Found only 1 ½ degrees northwest of the Lagoon Nebula. Ideal conditions and sharp eyes might detect M21, which is located just ½ degree northeast of M20, although it is rather faint by binocular standards. Omega Nebula – M17, also called the Swan, the Horseshoe or the Checkmark, this nebula can be seen clearly in binoculars. In Scorpius, Antares, or Rehua in Maori is the Heart of the Scorpion. A red giant star about 10,000 times more luminous than the Sun is a good binocular object. M4, is a globular cluster that in binoculars looks like a fuzzy patch. M6 the Butterfly Cluster, is a large open cluster of about 50 stars resembles a butterfly. M7 This large, bright open cluster, lying southeast of M6, needs to be seen through binoculars to be fully appreciated. NGC 6231 This bright open cluster lies in a rich region of the Milky Way. It is best surveyed in binoculars or at very low power in a telescope. In this same area of the scorpion’s tail are several other binocular-visible objects but I will let you discover these as that region of the sky comes about and remember that you don’t need fancy telescopes to enjoy the night sky but a pair of good binoculars (okay maybe a tripod for them too), a good sky atlas, and lots of hot chocolate.
It’s winter time here in the Southern Hemisphere and the nights are crisp and cold, but boy they are so beautiful!
- And finally… the Planets. Well at least some of them – visible with the naked eye.
- Mercury is the evening star at the beginning of the month, moving towards the Sun at the end of it
- Venus is in the morning sky, transiting Gemini and moving into Cancer at the end of the month
- Mars is very close to the Sun, in Cancer
- Jupiter is in Virgo.
- Saturn in Scorpius…