Palmerston North Astronomy

This was my view of the triple conjunction last evening that included Venus, the 22.8% lit crescent Moon, and Spica (the brightest star in Virgo) after it suddenly cleared after sunset.

I thought that I had missed this close conjunction of the Moon and Venus tonight. The weather has been so terrible all day. A strong, blustery and bitterly cold southerly is bashing us after having passed over the freshly fallen snow on the Tararuas. I walked into my kitchen to boil the jug for a cuppa when I saw a light in the sky. I then realized that there were two lights and the Moon and Venus were sitting in a small gap in the clouds. I quickly assembled the camera and tripod an rushed outside to find a mob of sheep sheltering on the north side of my house out of the wind. This is a crop from my 135mm view. Thanks for the hat Tip from Naomi Austen-Reid in Kaitaia to remind me that it was actually happening tonight! Although not identical, tonight's conjunction reminds of a similar close conjunction that occurred on my 18th birthday, some 51 years and one week ago. I made this composite up using Stellarium to show both how the pair sat that night and also the difference in phase of the crescent moon between the two nights, as well as the different phase of Venus as well. Both of the inner planets exhibit phases the same as the Moon at times. The great thing about the one in 1975 was that the phase was the same for both of them! A very rare occurrence BTW.

Welcome to Mid-Winter’s Day! Some of you might be confused because you may have been told many times in your life that Mid-Winter’s Day is at the June Solstice in the southern hemisphere. The answer as to why there are two different days offered is due to two different cultural regimes influencing us from the past. The only reason that we have seasons at all is because of the 23.3⁰ tilt of the Earth’s axis in relation to its orbit around the sun. This means that the sun reaches its most northern point around June 21st, and six months later the sun is at its most southern point, a difference in height at noon of nearly 47⁰. In between the sun crosses overhead at the Earth’s equator to give us equal day & night, a time that we call the equinoxes.

The cultures of the ‘Fertile Crescent’ once dominated by the Babylonians determined that those cardinal dates denote the start of the four seasons. This belief spread to Ancient Greece and onto Rome then the rest of Europe. Meanwhile a counter view evolved in China and across to the widespread culture of the Celts who dominated central and northern Europe two thousand years ago. The Cino-Celtic seasons start at what we call the “Cross Quarter Days,” the days halfway between the solstices and equinoxes. By the latter determination today is the first day of spring in the southern hemisphere. I believe that the thinking that led to the Cino-Celtic version of the seasons came about due to a prolonged period where benign weather saw spring like weather dominating the next six weeks. In the northern hemisphere this occurs in early February. Groundhog Day is a relic of that belief in a way, the difference being that they use the reaction of a groundhog to determine if they are to get another six weeks of winter or a change to spring weather.

Just in case you hadn’t noticed today is definitely not spring like at all. We had one of the heaviest frosts of the year today after a fairly large dump of snow on the main dividing ranges of the North Island (not to mention snow down to sea level in the South Island the day before). I believe that if we had Wombats here in the North Island they would make a great substitute for a Ground Hog on this day. Maybe our Aussie neighbours in their high-country areas could take the idea up?

Happy Imbolic everyone.

August evenings are a great time to walk outside and look directly up and see the Winter Milky Way passing through the zenith (directly overhead). The Tail of the Scorpion is also known as ‘The Fishhook of Maui’ and is seen to drag ‘Te Ikaroa,’ the Milky Way up from the southeast through the zenith and back down to the southwest over the coming months. Pick a night like tonight when there is no moon around to get the best views of our brilliant Milky Way even from the suburbs!

Well so much for being the last "Matariki" image for the season. Nature called before dawn. After that I popped outside to check the sky and this was the view from my backdoor. Notice that Mars is moving down and away from Matariki as the days go by.

Once again, it cleared unexpectedly by sunset last night. It gave me the opportunity to catch the first part of a developing triple conjunction involving the waxing crescent Moon, Venus, and the brightest star in Leo, Regulus. The Moon will move up through the latter two tonight and tomorrow night. When we look at the ‘horns’ of the crescent Moon they indicate the angle of the ‘ecliptic’ (the apparent path of the sun, and where we also find the planets and the Moon). As we close in on spring in September, the ecliptic steepens, without becoming vertical, reaching its maximum on the first day of spring, around September 22nd. The bright star Regulus (Alpha Leonis) sits very close to the line of the ecliptic as well.

By the end of ‘astronomical twilight,’ when the sun is 18⁰ below the horizon, we can see a phenomenon called the ‘Zodiacal Light,’ The ‘Z-light.’ Thanks to the dust of hundreds of comets that have passed through the inner solar system over the years we can see an inverted cone of light pointing up from the horizon along the line of the ecliptic where the Zodiac constellations lie.

The last photo is the view looking south in the early evening and shows how the “Pointers” and Crux, “the Southern Cross,” are at their highest point on the southern meridian.

I have included two charts courtesy of ‘Stellarium’ showing the ongoing conjunction for those lucky enough to have clear skies.

This will be my last image for this year's 'Matariki Season.' I took this wide view capturing Matariki just above the Cyprus Cedar tree and Marama (the Moon) hanging off a lower branch to the right. This was at 6.33am and there was a heavy frost all around me at the time. the frost got heavier by the time the sun rose BTW.

Yesterday my mate John Honore from Levin and I travelled over to near Masterton for a Special General Meeting and the annual General Meeting of The Phoenix Astronomical Society that I am president of. the meetings both went well, but there was no observing afterwards as there was a low cloud sealing on the other side of the ranges. When we got back to my place at Sluggish Creek near Glen Oroua on the Manawatu Plains it was 11.30p.m. When I stepped out of the car there was already a good frost on the ground and John's car was covered in ice! When I looked up I was blown away by a pristine, transparent, dark sky with the Winter Milky Way just coming down off the zenith! This is a partial Fisheye view of what greeted us last night!

I got up before dawn this morning and caught Matariki (The Pleiades) beside Marama (the Moon). There was fog around and a frost setting in. The fog created a bright, lunar corona (not a halo, they are much bigger). This made it hard to get a well balanced shot light-wise, so for this image I have overlaid a correct lunar exposure. I have also adapted a Stellarium image to show what is available tomorrow morning for early risers as it is predicted to be another frosty morning here again. Don't forget go along to the Leisure centre in Ferguson St by the Council Depot to here our president Matthew Willey speak on "The Stars of Matariki." It should be very entertaining for one and all.

We say goodbye to Mercury by July 4th, then Jupiter by around the 10th, so tonight was a last chance to see them both close together in the NW during twilight. Mercury will be back with Venus in early October just as Venus exits the evening sky for 2026.